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1
Lee, Graham Mark. "Fluorocarbene, Fluoroalkyl, and Fluoride Complexes of First-Row Transition Metals." Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/36704.
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Fluorinated organic compounds play important roles in our society, as these products range from life-saving pharmaceuticals and agrochemicals, to fluoropolymers with extremely high thermal and chemical stability. Although elemental fluorine (F2) is the most reactive element, some fluoro-organic compounds are chemically inert. As such, controlled reactivity of fluorine or highly-fluorinated organic fragments is a considerable, yet important challenge for synthetic chemists.
Fluoro-organometallic chemistry has been studied for decades, as researchers attempt to maximize the potential of metal mediated/catalyzed processes for the synthesis of fluorinated organic molecules. Within this framework, metal fluorocarbene complexes are particularly interesting because of their highly tunable reactivity, and are proposed for use in important metathesis/polymerization reactions of perfluorinated alkenes. While considerable work is still needed to make these proposed reactions a reality, this thesis outlines contributions from our research group. We showed that cobalt fluorocarbene complexes CpCo(=CFRF)(PPh2Me) (RF = F, CF3) undergo [2+2] cycloaddition reactions with tetrafluoroethylene (TFE) and phenylacetylene to form perfluorometallacyclobutane and partially fluorinated metallacyclobutene products, respectively. For both reactions, computational studies reveal a stepwise ring-closing mechanism, which proceeds through a singlet 1,4-diradical intermediate.
Next, the formation of CpCo(=CF2)(L) complexes is achieved via the direct addition of difluorocarbene, generated in situ, to a cobalt(I) precursor. Subsequent addition of CF2 to cobalt fluorocarbene complexes results in [2+1] cycloaddition and formation of perfluorinated alkene complexes. The [2+1] addition is highly favored as the cobalt fluorocarbenes readily react with electrophilic CF2. A series of experiments provide evidence for the stepwise nature of fluoroalkene complex formation.
From Co(I) fluorocarbene complexes, the focus shifts to preparing metal fluorocarbenes with electrophilic-type reactivity. The synthesis of bis(perfluoroalkyl) complexes serve as precursors for preparation of perfluoroalkyl cobalt(III) fluorocarbenes, which undergo migratory insertion reactions of the fluorocarbene into the perfluoroalkyl ligand. Using a similar synthetic approach, nickel(II) and palladium(II) difluorocarbene complexes are prepared from their corresponding trifluoromethyl precursors.
The synthesis, characterization and reactivity of cobalt(III) fluoride complexes is also described, including the catalytic fluorination of acyl chlorides, demonstrating the first example of a cobalt(III) catalyzed fluorination reaction. The effects of the various ancillary ligands on these cobalt catalysts are investigated using high-throughput experimentation technology, and the scope of the reaction is expanded to include the synthesis of a variety of acyl fluoride compounds.
Finally, the results and learnings from this work will be summarized and highlighted. The future directions and novel research which could result from the continuation of these projects is discussed, with an emphasis placed on the areas believed to have the highest potential impact.
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Sole, Kathryn Clare. "Solvent extraction of first-row transition metals by thiosubstituted organophosphinic acids." Diss., The University of Arizona, 1993. http://hdl.handle.net/10150/186480.
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Organophosphorus compounds are well known as solvent-extraction reagents. Two new reagents in this class are Cyanex 302 and Cyanex 301, the respective mono- and dithio analogs of the commercial extractant, Cyanex 272 (bis(2,4,4-trimethylpentyl)-phosphinic acid). The replacement of oxygen by sulfur in these reagents decreases their pKₐ, and enables extraction to be carried out at much lower pH than previously attained. A comparative characterization of Cyanex 272, Cyanex 302, and Cyanex 301 is undertaken. The aggregation and partitioning behavior of these reagents is determined. A comparison of the solvent extraction behavior of first-row transition-metal ions from manganese to zinc in acidic sulfate solution by these reagents is reported. Distribution coefficients shift to lower pH with increasing sulfur substitution of the extractant, the greatest effect being observed for soft Lewis acids. These reagents are found to be strong extractants for the transition metals examined, but poor extractants for alkaline-earth ions and manganese(II). Certain metal ions, in particular copper(II) and silver(I), are, however, extremely difficult to strip, which may mitigate against potential applications. Stoichiometry of the extraction reactions and the nature of the metal complexes formed are postulated based on slope-analysis techniques and spectroscopic and molecular-mass measurements. Molecular modelling of the extractants and extracted species is presented. Some reasons for the enhanced stability of the complexes formed with certain metals are discussed in terms of d-electron effects, donor-/acceptor-atom interactions, ligand-field observations, and steric effects associated with the extractants.
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Salt, J. E. "[1,2-bis(dimethylphosphino)ethane] complexes on the first row transition metals." Thesis, Imperial College London, 1985. http://hdl.handle.net/10044/1/37844.
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Radulović, Stojan. "Solvation, reactivity and spectroscopy of complexes of some first row transition metals." Thesis, University of Leicester, 1988. http://hdl.handle.net/2381/27867.
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The work in this thesis is mainly concerned with the discussion of effect of solvation on the reaction kinetics of inorganic complexes. Rate constants for chemical reactions in various aqueous cosolvent systems have been measured and analysed. Crystal structure of several Fe (II) complexes are analysed from crystallographic data for possible structural parameters which might have effect on solvation. Solubility data, for a range of inorganic salts containing simple and complex ions, are reported for aqueous solutions and for solutions in aqueous cosolvent mixtures. Transfer chemical potentials for single ions in aqueous i-PrOH and t-BuOH solvent mixtures are determined using solubility data for salts in conjunction with TATB, tetraphenylarsonium tetraphenylboranate, assumption and are compared with those in corresponding aqueous methanol, ethanol and acetone solvent mixtures. Kinetic data are reported for reaction between [Fe (gmi)3]²+ and hydroxide ions at atmospheric and elevated pressures in above binary aqueous mixtures. Initial state and transition state analysis of reactivity trends for hydroxide attack on other Fe (II) diimine complexes in aqueous methanol solvent mixtures are reported. Dependence of visible absorption spectra on solvent has been examined for a number of Fe (II) and Fe (III) mixed ligand complexes. Preliminary redox study of the of Fe (II) and Fe (III) complexes is also reported.
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Moneo, Corcuera Andrea. "Bistable molecular materials: triazole-based coordination chemistry of first row transition metals." Doctoral thesis, Universitat Rovira i Virgili, 2019. http://hdl.handle.net/10803/668881.
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En la present tesi doctoral presentem el magnetisme molecular bàsic de compostos de coordinació basats en un lligant di-anionico: (L-2 = 4- (1,2,4-triazole-4-il) etanosulfonato). En particular, vam estudiar el fenomen de transició d'espín d'un trímer de ferro (II) poli-aniònic en diferents escales, des d'una escala macroscòpica ("bulk") fins a nivells moleculars, acabant amb la deposició en superfície. D'una banda, el comportament SCO "macroscòpic" es va modular canviant l'empaquetatge de vidre i la connectivitat entre els trímers amb una estratègia d'intercanvi catiònic. D'altra banda, hem trobat bi-estabilitat en sistemes altament diluïts del trímer de Fe (II), en una solució mixta sòlida i en dissolució, on les forces de cooperació entre trímers s'hi han reduït fins a nivells moleculars. Aquest resultat ens anima a estudiar la deposició i el comportament del trímer en diverses superfícies amb vista a un primer acostament cap a una aplicació real. Finalment, hem fabricat una pel·lícula nanomètrica del compost sobre sílice, amb propietats de transició d'espín intactes. A més, també vam poder impulsar el procés de miniaturització més enllà de la mida nanomètrica en créixer una subcapa ordenada del complex en una superfície d'or a través d'una deposició d'alt buit.En la presente tesis doctoral presentamos el magnetismo molecular básico de compuestos de coordinación basados en uno ligando *di-*anionico: (L-2 = 4- (1,2,4-*triazole-4-*il) *etanosulfonato). En particular, estudiamos el fenómeno de transición de espín de un trímero de hierro (II) *poli-aniónico en diferentes escalas, desde una escala macroscópica ("*bulk") hasta niveles moleculares, acabando con la deposición en superficie. Por un lado, el comportamiento *SCO "macroscópico" se moduló cambiando el empaque de vidrio y la conectividad entre los trímeros con una estrategia de intercambio catiónico. Por otro lado, hemos encontrado *bi-estabilidad en sistemas altamente diluidos del trímero de Fe (II), en una solución mixta sólida y en disolución, donde las fuerzas de cooperación entre trímeros se han reducido hasta niveles moleculares. Este resultado nos anima a estudiar la deposición y el comportamiento del trímero en varias superficies en orden a un primer acercamiento hacia una aplicación real. Finalmente, hemos fabricado una película *nanomètrica del compuesto sobre sílice, con propiedades de transición de espín intactos. Además, también pudimos impulsar el proceso de miniaturización más allá de la medida *nanomètrica al crecer una *subcapa ordenada del complejo en una superficie de oro a través de una deposición de alto vacío.
At the present doctoral thesis present the basic molecular magnetism of compounds of coordination based at one binding *di-*anionico: (*L-2 = 4- (1,2,4-*triazole-4-*il) *etanosulfonato). In particular, we studied the phenomenon of transition of spin of a trimer of iron (*II) *poli-*aniònic at distinct scales, since a macroscopic scale ("*bulk") until molecular levels, ending with the deposition at surface. On the one hand, the behaviour *SCO "macroscopic" modulated capsizing the packaging of glass and the connectivity among the trimers with a strategy of exchange *catiònic. On the other hand, we have found *bi-stability at systems highly diluted of the trimer of Faith (*II), at a solid mixed solution and at dissolution, where the forces of cooperation among trimers have reduced until molecular levels. This result warms us at studying the deposition and the behaviour of the trimer at several surfaces with a view to a first approach to a real app. Finally, we have fashioned a film *nanomètrica of the compound on silica, with properties of transition of intact spin. Besides, also we could further the process of miniaturisation further of the size *nanomètrica at growing a *subcapa ordered of the complex at a surface of gold through a deposition of tall void.
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Scharf, Austin Bennett. "First-Row Transition Metal Complexes of Dipyrrinato Ligands: Synthesis and Characterization." Thesis, Harvard University, 2013. http://dissertations.umi.com/gsas.harvard:11090.
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A library of variously-substituted dipyrrins and their first-row transition metal (Mn, Fe, Cu, Zn) complexes have been synthesized, and the effects of peripheral substituents on the spectroscopic, electrochemical, and structural properties of both the free-base dipyrrins and their metal complexes has been explored. The optical and electrochemical properties of the free dipyrrins follow systematic trends; with the introduction of electron-withdrawing substituents in the 2-, 3-, 5-, 7-, and 8-positions of the dipyrrin, bathochromic shifts in the absorption spectra are observed, oxidation becomes more difficult, and reduction becomes more facile. Similar effects are seen for iron(II) dipyrrinato complexes, where peripheral substitution of the dipyrrinato ligand induces red-shifts in the absorption spectra and increases the oxidation potential of the bound iron. Steric interactions between the peripheral halogens and the 5-substituent of the dipyrrinato ligand can induce distortion of the ligand from planarity, resulting in widely varying 57Fe Mössbauer quadrupole splitting (|ΔEQ|) parameters.Chemistry and Chemical Biology
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Brunker, Timothy J. "Studies of half-sandwich tris(pyrazolyl)borate complexes of first row transition metals." Thesis, University of Oxford, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.393565.
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Rodríguez, Serrat Mònica. "First row transition metal carbenes: from supporting ligands to organic reactive fragments." Doctoral thesis, Universitat de Girona, 2019. http://hdl.handle.net/10803/668829.
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In the last decades, carbenes have shown a huge potential and versatility in organometallic and organic chemistry. In each of these fields, first row transition metal chemistry is less developed than noble metal complexes. In the pursuit of more environmentally friendly systems, this thesis will be focused on the development of new organometallic complexes and reactivities using earth abundant metals.
In the organometallic field, the synthesis of a novel ligand bearing a chelating scaffold and a mesoionic carbene moiety has allowed the preparation of a family of first row transition metal complexes.
Using carbenes as intermediates in organic synthesis, the functionalization of aromatic Csp2-H bonds and aliphatic Csp3-H bonds by the activation of diazoacetates could be developed using non-heme iron complexesEn les últimes dècades, els carbens han mostrat un gran potencial i versatilitat tan en la química organometàl·lica com en la orgànica. En qualsevol d’aquest camps, els metalls de la primera sèrie de transició han estat menys utilitzats que els metalls nobles. Davant la recerca de sistemes que siguin més benignes amb el medi ambient, aquesta tesi està enfocada al desenvolupament de nous complexes organometàl·lics i reactivitats utilitzant metalls abundants a la natura. En el camp de la organometàl·lica, la síntesi d’un lligand nou el qual combina una estructura quelatant i un carbè mesoiònic va permetre la síntesi de complexos amb metalls de la primera sèrie de transició amb interessants propietats. Utilitzant carbens com a intermedis en síntesi orgànica, s’ha descrit la funcionalització d’enllaços Csp2-H aromàtics i d'enllaços Csp3-H alifàtics a través de l’activació de diazoacetats, utilitzant complexos de ferro no hemo
9
Tilford, Claire. "Experimental investigations of the electronic interactions within multinuclear first row transition metal complexes." Thesis, University of East Anglia, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302144.
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Sazama, Graham Thomas. "Late First-Row Transition Metals in Weak Ligand Fields - Correlating High-Spin Electronic Structure and Reactivity." Thesis, Harvard University, 2013. http://dissertations.umi.com/gsas.harvard:11012.
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High spin has been shown to be necessary for optimal reactivity of transition metal complexes toward the activation and functionalization of C-H bonds. This thesis presents our examination of the weak-field, tripodal, trianionic tris(pyrrolyl)ethane (tpe) ligand and its complexes. Outer-sphere oxidation of the manganese, iron, cobalt, nickel and zinc complexes of tpe were performed by electrochemical and chemical methods. Electrochemical oxidation occurred at the same potential for each species, suggesting a ligand-based oxidation. The reaction product of chemical oxidation of iron showed oxidation of a pyrrole unit followed by H-atom abstraction to form a dichelated species. Density functional theory calculations confirm these results, and in silico oxidation of the complexes is entirely ligand-based. These results establish that tpe complexes are oxidized at the pyrrolide subunits in outersphere electron transfers, and elucidate minimal metal-ligand electronic communication. The more reactive \([(tpe)Fe(THF)]^−\) anion exhibits rapid binding of three equivalents of tert-butyl isonitrile, while reaction with excess carbon monoxide induces ligand fragmentation to form a species wherein two molecules of carbon monoxide have been reductively coupled. A mechanism based on the observed isonitrile species is proposed. The use of inner-sphere oxidant reagents allows for several stable iron (III) complexes of tpe to be isolated and characterized. Alkyl peroxides and alkyl disulfides, organic azides, and diphenyldiazomethane are all shown to oxidize iron by a single electron. Reaction with organic azides results in the formation of iron (III) amide species, likely as a result of Hatom abstraction. The weak-field of tpe creates a high propensity for forming high-spin iron (III) complexes, to the extent that diphenyldiazoalkane acts as a redox-active ligand and provides a one-electron reservoir to reveal a high-spin \(Fe^{3+}\). Spectroscopic and computational studies were undertaken to rigorously assign the physical oxidation state of iron in all cases. Given the outer-sphere redox liability of the tpe ligand, and the capability for inner-sphere oxidation local to iron, tpe complexes of iron represent a new class of metal-ligand redox activity, wherein the metal and ligand form two separate redox reservoirs, accessible via different mechanisms.Chemistry and Chemical Biology
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Arbogast, James K. "Chromatographic behavior of anions and the first row transition metal ions /." The Ohio State University, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487335992905515.
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Roldán, Gómez Steven. "Computational mechanistic studies of C-H and C-X activated organometallic species with first-row transition metals." Doctoral thesis, Universitat de Girona, 2020. http://hdl.handle.net/10803/668858.
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During the last decades, computational chemistry has become a resourceful
tool in the quest to understand and predict the mechanism and the reactivity
of chemical systems. This is especially true in the area of organometallic
catalysis, where the computational models used nowadays show better
accuracy/computational-cost ratio compared to the ones of a few decades ago. In addition, it has become common practice to rationalize the mechanistic
proposals for a specific reaction based on combined computational and
experimental evidence. The role of computational chemistry is particularly
relevant when there is not enough experimental evidence due to the elusive
nature of the intermediate and reactive species.
This thesis addresses the calculations performed to determine the mechanism
of four different organometallic reactions catalyzed by first-row transition
metals that were developed in tight synergic collaboration with the
experimental researchers of our groupDurant les últimes dècades, la química computacional s'ha convertit en una eina molt útil per indagar i comprendre els mecanismes que regeixen els sistemes químics. Especialment en l'àrea de la catàlisi organometàl·lica, on els models computacionals poden tenir una bona relació entre precisió / cost computacional. A més, avui en dia es una pràctica habitual racionalitzar propostes mecanístiques, per a una reacció específica, basats en evidències tant computacionals com experimentals. El paper de la química computacional és particularment rellevant en els casos en què no hi ha prou evidència experimental, a causa de la naturalesa evasiva de les espècies intermèdies. Aquesta tesi aborda els càlculs realitzats en la determinació del mecanisme de quatre reaccions organometálicas diferents, catalitzades per metalls de transició de la primera sèrie, que es van desenvolupar en estreta col·laboració amb els investigadors experimentals del nostre grup
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Pelosin, Primavera. "Molecular water oxidation catalysts based on first row transition metal complexes." Doctoral thesis, Universitat Rovira i Virgili, 2020. http://hdl.handle.net/10803/670969.
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L'objectiu d'aquesta tesi era estudiar el procés d'oxidació de l'aigua mitjançant catalitzadors moleculars basats en
metalls de transició de primera fila. En el capítol tres es va demostrar la importància del disseny de lligands en la
formació de catalitzadors d’oxidació d’aigües resistents (WOC) basats en coure. Es va demostrar que un lligand tetraamidate
macrocicle (TAML) estabilitza el complex durant la catàlisi mitjançant la deslocalització de les càrregues
positives generades. A més, l'efecte macrocicle impedeix la desmetal·lació àcida del catalitzador, que era actiu també
a pH neutre. En el quart capítol es va descriure un procediment innovador per formar ànodes moleculars. El WOC
basat en Cu de TAML descrit anteriorment es va modificar amb restes de pirè, formant dos regioisòmers amb
propietats electròniques diferents. Tots dos regioisòmers es van ancorar a la superfície d’elèctrodes d’òxid d’estany
d’indi (ITO) mitjançant l’electropolimerització dels fragments de pirè en dissolvents orgànics. L'activitat dels ànodes es
va provar mitjançant l'elèctrode de disc d'anell rotatiu (RRDE) a pH 7,5, 9 i 10.
El capítol cinc es centra en la determinació de la naturalesa real de la catàlisi. Aquest estudi pren com a exemple un
complex de ferro pentanuclear, considerat un WOC molecular, que en realitat es descompon en presència d’aigua i
d’alts potencials. Es va confirmar que l’espècie activa era hematita mitjançant diverses anàlisis com EDX, SEM, XPS i
XAS.El objetivo de esta tesis fue estudiar el proceso de oxidación del agua mediante catalizadores moleculares basados en metales de transición de primera fila. En el capítulo tres se demostró la importancia del diseño de ligandos en la formación de catalizadores de oxidación de agua (WOC) resistentes basados en cobre. Se demostró que un ligando tetra-amidate macrociclo (TAML) estabiliza el complejo durante la catálisis mediante la deslocalización de las cargas positivas generadas. Además, el efecto del macrociclo evita la desmetalización ácida del catalizador, que también era activo a pH neutro.En el cuarto capítulo se describió un procedimiento innovador para formar ánodos moleculares. El WOC basado en Cu de TAML descrito anteriormente se modificó con pireno, formando dos regioisómeros con distintas propiedades electrónicas. Ambos regioisómeros se anclaron en la superficie de electrodos de óxido de indio y estaño (ITO) mediante electropolimerización del pireno en disolventes orgánicos. La actividad de los ánodos se evaluó mediante un electrodo de disco de anillo giratorio (RRDE) a pH 7,5, 9 y 10. El capítulo cinco se centra en la determinación de la naturaleza real de la catálisis. Este estudio toma como ejemplo un complejo de hierro pentanuclear, considerado un WOC molecular, que en realidad se descompone en presencia de agua y altos potenciales. Se confirmó que la especie activa era hematita mediante varios análisis como EDX, SEM, XPS y XAS.
The objective of this thesis was to study the process of water oxidation through molecular catalysts based on first row transition metals. In chapter three was proved the importance of ligand design in the formation of rugged water oxidation catalysts (WOCs) based on copper. A tetra-amidate macrocycle ligand (TAML) was proved to stabilize the complex during catalysis through -delocalization of the generated positive charges. Further the macrocycle effect prevents the acidic demetallation of the catalyst, which was active also at neutral pH. In the fourth chapter was described an innovative procedure to form molecular anodes. The previously described TAML Cu-based WOC was modified with pyrene moieties, forming two regio-isomers with distinct electronic properties. Both the regio-isomers were anchored on the surface of indium tin oxide (ITO) electrodes through electropolymerization of the pyrene moieties in organic solvents. The anodes activity was tested through rotating ring disk electrode (RRDE) at pH 7.5, 9 and 10. The Chapter five is focused on the determination of the real nature of the catalysis. This study takes as an example a pentanuclear iron complex, considered a molecular WOC, which actually decomposes in presence of water and high potentials. The active species was confirmed to be hematite through several analysis as EDX, SEM, XPS and XAS.
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Kemp, Jeremy. "Electron spectroscopy and electronic structure of first row transition metal oxides." Thesis, University of Oxford, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.257736.
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Hemming, Oliver. "Structure and reactivity of low-coordinate first-row transition metal complexes." Thesis, University of Manchester, 2018. https://www.research.manchester.ac.uk/portal/en/theses/structure-and-reactivity-of-lowcoordinate-firstrow-transition-metal-complexes(a7879b58-897e-4080-99f6-8551511a503a).html.
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Earth-abundant first-row transition metals have seen a renaissance in chemistry in recent years due to their relatively low toxicity and cost in comparison to precious metals. Furthermore open-shell transition metal complexes exhibit useful one-electron redox processes which contrasts to their heavier d block anologues. This thesis aims to synthesize and analyse the structure and reactivity of low-coordiante first-row transition metal complexes of from groups 7-9 with an aim to utilize these species in catalysis. The divalent compound [Co{N(SiMe3)2}2] reacts with the primary phosphines PhPH2 in the presence of an NHC ligand (IMe4) to yield the phosphinidene bridged dimer [(IMe4)2Co(µ-PMes)]2. The complex has interesting magnetic properties due to strong antiferromagnetic coupling between the two cobalt(II) centres. Increasing the steric bulk of the NHC yielded carbene-phosphinidene adducts (NHC·PAr). This transformation was shown to be catalytic. The structure and reactivity of complexes of the type [(NHC)xMn{(N(SiMe3)2}2] were investigated. The complexes exhibit similar structural properties to their iron and cobalt analogues; however their reactivity has been shown to differ. The addition of primary phosphines to complexes of the type [(NHC)xMn{N(SiMe3)2}2] yielded a range of manganese phosphide complexes. [Mn{N(SiMe3)2}2] also reacts with imidazolium salts at elevated temperatures to yield heteroleptic manganese NHC complexes. The reaction of [Mn{N(SiMe3)2}2] with IPr·HCl afforded the abnormal carbene complex [(aIPr)Mn{N(SiMe3)2}µ-Cl]2. A new monoanionic bidentate ligand is reported which has shown to be a useful ligand system to stabilize three-coordiante iron(II) complex. The reaction of [(L)Fe(Br)] with mesitylmagnesium Grignard or n-butyllithium yield the iron hydrocarbyls [(L)Fe(Mes)] and [(L)Fe(nBu)] with the latter being stable to β-hydrogen elimination. Finally [(L)Fe(nBu)] has been utilized as a pre-catalyst in the hydrophosphination of internal alkynes, showing selectivity for the E-isomeric vinylphosphine.
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Tilling, Matthew John. "Alternative approaches to orbital optimisation in first row transition metal systems." Thesis, University of Warwick, 2015. http://wrap.warwick.ac.uk/87866/.
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Two new methods to aid in the calculation of ab initio energies are presented. The first method sets out to change the way that systems that have multiple elements that would benefit from a multireference treatment are handled. The method proposes splitting the system into multiple small active spaces in order to avoid the computational issues present with a single large active space. The method is developed using localised orbitals and tested on Cr2 and the molecule N2 both at long bond lengths. The second method proposes and develops a method for the production of starting orbitals for CASSCF and CASPT2 calculations. This method requires multiple subunits of the system which are then optimised to produce subsets of orbitals. These orbitals are then combined using a custom script (detailed within) to form a coherent orbital set for the entire system. This method is then tested on two transition metal complexes, one of which could not be successfully treated using traditional methods. Along with the two new methods, two studies of individual transition metal systems are presented. The first covers a comparison between a published DFT/OLYP study of complexes of the form (nacnac)MIII (NPh) with a DFT/B3-LYP, CASSCF, CASPT2 and CCSD(T) study of similar systems presented here. The second studies the complex [CrII (CN)5 ] 3– . It produces a possible transition state, and discussed its role in a Berry pseudorotation-like mechanism for this system.
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Ansari, Nasrin. "Coordination properties of aminophosphine with first row transition metal nitrosyl complexes." Thesis, University of Ottawa (Canada), 1994. http://hdl.handle.net/10393/6862.
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The synthesis of the new thermolabile ironnitrosylhydride complex FeH(NO)(CO)(dppf) is reported. (dppf = 1,1$\sp\prime$-bisdiphenyl phosphino-ferrocene). The facile decomposition of FeH(NO)(CO)(dppf) is interpreted in terms of a homolysis of the Fe-H bond and of a nitrosyl transfer reaction. The synthesis of the structurally characterized iron complex Fe(O=PPh$\sb2$(2-Py))$\sb3\sp2\sp+\cdot$2BF$\sb4\sp-$, by the reaction of Fe(NO)$\sb2$(THF)$\sb2\sp+$ with PPh$\sb2$(2-Py) is described. The proposed mechanism for the formation of Fe(O=PPh$\sb2$(2-Py))$\sb3\sp2\sp+\cdot$2BF$\sb4\sp-$ involves a combination of disproportionation and oxygen transfer reactions. This dipositive iron complex is the first example of a first row transition metal chelated by the oxide of diphenyl(2-pyridyl)phosphines. The synthesis and the reactivity of the cobaltdinitrosyl monometallic Co(NO$\sb2$(PPh$\sb2(2$-Py))$\sb2\sp+\cdot$BF$\sb4\sp-$, Co(NO)$\sb2$(Py)$\sb2\sp+\cdot$BF$\sb4\sp-$, Co(NO)$\sb2$(Py)$\sb2\sp+\cdot$BPh$\sb4\sp-$ and bimetallic Co$\sb2$(NO)$\sb3$(PPh$\sb2$(2-Py))$\sb2\sp+$ -BPh$\sb4\sp-$ complexes are reported. The single crystal X-ray diffraction study of Co(NO)$\sb2$(PPh$\sb2$(2-Py))$\sb2\sp+$BF$\sb4\sp-$ shows that the aminophosphine ligands are co-ordinated through their P-donor sites. In solution, Co(NO)$\sb2$(Py)$\sb2\sp+$BF$\sb4\sp-$ was stable whereas, Co(NO)$\sb2$(Py)$\sb2\sp+$BPh$\sb4\sp-$ decomposed rapidly. The structural study of Co(NO)$\sb2$(Py)$\sb2\sp+$BF$\sb4\sp-$ has led to the proposal of a new theoretical model in which the non-bonded repulsions between the NO and L ligands of the M(NO)(L) moieties provide the most influential factor for fixing the value of the (O)N-M-N(O) angle. The structurally characterized Co$\sb2$(NO)$\sb3$(PPh$\sb2$(2-Py))$\sb2\sp+$ -BPh$\sb4\sp-$ complex is the first example of a bimetallic containing two metal-metal bonded first row transition metals with diphenyl(2-pyridyl)phosphine as a bridging ligand. It is also the first example of a Co$\sb2$(NO)$\sb3\sp+$ bimetallic core stabilized by two diphenyl(2-pyridyl)phosphine ligands coordinated by the P and N donor sites of the ligands arranged in a head-to-head fashion.
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Stevens, Michaela. "Fundamentals and Industrial Applications: Understanding First Row Transition Metal (Oxy)Hydroxides as Oxygen Evolution Reaction Catalysts." Thesis, University of Oregon, 2017. http://hdl.handle.net/1794/22633.
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Intermittent renewable energy sources, such as solar and wind, will only be viable if the electrical energy can be stored efficiently. It is possible to store electrical energy cleanly by splitting the water into oxygen (a clean byproduct) and hydrogen (an energy dense fuel) via water electrolysis. The efficiency of hydrogen production is limited, in part, by the high kinetic overpotential of the oxygen evolution reaction (OER). OER catalysts have been extensively studied for the last several decades. However, no new highly active catalyst has been developed in decades. One reason that breakthroughs in this research are limited is because there have been many conflicting activity trends. Without a clear understanding of intrinsic catalyst activity it is difficult to identify what makes catalysts active and design accordingly. To find commercially viable catalysts it is imperative that electrochemical activity studies consider and define the catalyst’s morphology, loading, conductivity, composition, and structure.
The research goal of this dissertation is twofold and encompasses 1) fundamentally understanding how catalysis is occurring and 2) designing and developing a highly active, abundant, and stable OER catalyst to increase the efficiency of the OER. Specifically, this dissertation focuses on developing methods to compare catalyst materials (Chapter II), understanding the structure-compositional relationships that make Co-Fe (oxy)hydroxide materials active (Chapter III), re-defining activity trends of first row transition metal (oxy)hydroxide materials (Chapter IV), and studying the role of local geometric structure on active sites in Ni-Fe (oxy)hydroxides (Chapter V). As part of a collaboration with Proton OnSite, the catalysts studied are to be integrated into an anion exchange membrane water electrolyzer in the future.
This dissertation includes previously published and unpublished co-authored material.10000-01-01
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Kayi, Hakan. "Parameterization of the AM1 semiempirical molecular orbital method for the first-row transition metals and other elements." kostenfrei, 2009. http://d-nb.info/1000061620/34.
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Corona, Prieto Teresa. "Understanding C-H oxidation and amination reactions performed by late first-row transition metals: trapping high-valent metal-O/N species." Doctoral thesis, Universitat de Girona, 2017. http://hdl.handle.net/10803/401684.
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The transformation of C-H bonds into C-O/N bonds is a process of interest in organic synthesis, but controlling the reactivity and selectivity among the multiple C-H bonds existing in most molecules is a challenging task. Traditional methodologies usually rely on the use of stoichiometric reagents that generate important amounts of toxic waste and relatively harsh reaction conditions are required. An alternative to these traditional methods is the use of catalysts, which enable the performance of these transformations under mild conditions, with improved selectivities and using less hazardous reagents. However, finding good catalysts inevitably means that intimate details about the reaction mechanism need to be unraveled. One key issue to further develop more effective catalysts is to understand the mechanism. Thus, this doctoral dissertation is focused on obtaining mechanistic insight into these transformations by trapping the active species that is the high-valent metal-oxygen/nitrogen species based on late first-row transition metalsLa transformació d'enllaços C-H en enllaços C-N/O és un procés interessant en síntesi orgànica, però encara és un repte controlar la reactivitat i selectivitat entre els diferents enllaços C-H presents en les molècules. Les metodologies tradicionals solen estar basades en l'ús de reactius en quantitats estequiomètriques, generant importants quantitats de residus tòxics, i en condicions de reacció agressives. Una alternativa és l'ús de catalitzadors, els quals permeten dur a terme aquestes transformacions en condicions de reacció més suaus, millorant les selectivitats, i utilitzant reactius menys perillosos. No obstant, trobar nous catalitzadors implica conèixer en detall el mecanisme de les reaccions. Per això, aquesta tesi té com a objectiu estudiar els mecanismes d’aquestes transformacions a través de la detecció i estudi de les espècies actives, corresponents a compostos metall-oxigen o metall-nitrogen en alt estat d’oxidació basats en metalls de la primera sèrie de transició
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Linfoot, Charlotte Louise. "First row transition metal complexes for application to dye-sensitised solar cells." Thesis, University of Edinburgh, 2011. http://hdl.handle.net/1842/4870.
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Ruthenium (II) complexes are used extensively in photoelectrochemical and photophysical devices, such as Dye-Sensitized Solar Cells (DSSCs). The use of Cu(I) as a possible replacement for Ru(II) has to date had limited exploration, but has obvious advantages in terms of low cost and high abundance. However, Cu(I) typically undergoes conformational change from tetrahedral towards square planar upon oxidation or MLCT excitation, often leading to reduced stability, reduced electron transfer rates and reduced excited state lifetime, thus impairing useful function. Typically, steric constraints are used to prevent this; however these can often be synthetically intensive, involving multi-step and low yielding synthetic pathways. In this work, we explore “blocking” functionality using two different ligands combined with a range of bipyridyl ligands with varying substituent groups. The study has looked into the synthesis of heteroleptic Cu(I) complexes of the general formula: [Cu(POP)(bipyridyl)][BF4], where POP = bis[2-(diphenylphosphanyl)phenyl] ether, and [Cu(pmppE)(bipyridyl)], where pmppE = hydrazono pyrazol-5-thiones(one). The work presented in this thesis focuses on the synthesis, and subsequent photoelectrochemical and photophysical characterisation of Cu(I) complexes, yielding results that open new avenues for design of functional Cu(I) systems. Solar cell testing also revealed photovoltages comparable to those of existing Cu(I) DSSC sensitisers. An extensive spectroscopic study of [Cu(POP)(dmbpy)]+ and [Cu(POP)(tmbpy)]+ has revealed the latter to have the significantly larger quantum yield: 65 % and 4% respectively in PMMA at 300 K. A complimentary computational investigation was carried out in order to gain a better understanding of how structural rigidity affects emission properties.
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Armitage, Andrew Paul. "First row transition metal complexes as transmissive filters for astronomical X-ray polarimetry." Thesis, University of Leicester, 2012. http://hdl.handle.net/2381/27635.
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This thesis aims to develop single crystals that can act as transmissive X-ray polarising filters at K-edge energies corresponding to the first row transition metal series (M = Cu–Ti; K-edge range = 8.9–4.9 keV). Discrete square-based pyramidal co-ordination complexes have been targeted in which the apical M–X or M=O bonds display a high degree of intermolecular alignment. Chapter 1 provides an overview of X-ray polarisation dependence, existing X-ray polarimeters and current materials offering X-ray polarisation capabilities. Finally, a molecular design strategy for the thesis is outlined. In Chapter 2, [(4,4′-Me2bipy)2Cu2Br2(μ-C2O4)] (1a) has been subjected to a successful dichroic evaluation at the Cu (8.9 keV) and Br K-edges (13.5 keV). The origins of the X-ray dichroism in 1a have been modelled using two complementary theoretical methodologies; i) TD-DFT and ii) multiple scattering theory, which have identified the importance of the apical Cu–Br bond in SBP 1a. In Chapter 3 the motif [(α-diimine)MBr(β-diketonate)] has been targeted as an all purpose platform for the Cu (3–5, 8.9 keV), Ni (6, 8.4 keV), Co (7, 7.7 keV), Fe (10, 7.1 keV) and Mn (11, 6.4 keV)] K-edges. Highly aligned SBP 3a has been shown to display X-ray dichroism at the Cu K-edge. For 6, 7, 10 and 11, five co-ordinate metal centres can indeed be accessed using suitably tailored pyridylarylimine chelates; however, the geometries of the metal centres can be anywhere between distorted trigonal bipyramidal and distorted square-based pyramidal while the intermolecular alignment is variable. In Chapter 4 macrocyclic tetraphenylporphyrinato (TPP2-) has been employed as a rigid support to fill the basal co-ordination sites in SBP [(TPP)MX] (M = Co, X = Cl (15a); M = Co, X = Br (15b); M = Fe, X = Br (16); M = Mn, X = Br (17)] and [(TPP)MO] [M = V (18), Ti (19)]. Notable X-ray dichroism has been observed at the Co (7.7 keV), Fe (7.1 keV), V (5.5 keV) and Ti (4.9 keV) K-edges in highly aligned 15, 16, 18 and 19, respectively. The observed dichroic features in 15a and 18 have also been modelled using multiple scattering theory. In addition, compact hybrid filters were developed using TPP-modified [(Y2-TPP)FeX] [(Y = Cl, X = Br (20a); Y = Br, X = Cl (20b); Y = X = Br (20c)], which offer multiple K-edges in one molecule. Chapter 5 explores exclusively halides and oxides of the earlier transition metal elements [Cr (5.9 keV), V (5.5 keV), Ti (4.9 keV)], in which the pre-edge has been observed to reveal the most dominant X-ray polarisation dependence. Hence, M(III) complexes [(nacnac)MCl(β-diketonate] [M = Cr, β-diketonate = dbm (21), acac (22); M = V, β-diketonate = acac (23a), dbm (23b); M = Ti, β-diketonate = dbm (24)] have been targeted and selected examples have been deliberately oxidised to generate M(IV) oxides [(nacnac)MO(dbm)] [M = V (25), Ti (26)]. The FEFF code has been used to predict the polarised XAS spectra in an attempt to evaluate the feasibility of materials of this structural type. Chapter 6 gives overarching conclusions of the key themes of the thesis with a summary that highlight the contributions to the area and science in general.
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Liu, Xuan. "The First-Row Transition Metal-Based Electrocatalysts for Water Splitting and Biomass Upgrading." University of Cincinnati / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1613752182130801.
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Jiang, Nan. "First-Row Transition Metal Sulfides and Phosphides as Competent Electrocatalysts for Water Splitting." DigitalCommons@USU, 2017. https://digitalcommons.usu.edu/etd/6480.
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Conversion of renewable energy resources (such as solar and wind) through water splitting to hydrogen and oxygen has attracted increasing attention. The sole product of hydrogen combustion is water, rendering a carbon-neutral energy cycle. Water splitting consists of two redox half reactions: hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Both of these two transformations involve multi- electron/proton movement and thus are kinetically sluggish. In order to accelerate the reaction rates for practical application, efficient catalysts are needed. State-of-the-art catalysts for water splitting are usually composed of noble metals, such as platinum, ruthenium, and iridium, whose scarcity and high cost limit their wide employment. Consequently, it is of critical importance to develop competent and non-precious catalysts via low-cost preparation.
Owing to the thermodynamic convenience and potential application in proton exchange membrane and alkaline electrolyzers, traditionally, most HER catalysts were developed under strongly acidic conditions while OER catalysts under strongly alkaline conditions. In order to accomplish overall water splitting, the coupling of HER and OER catalysts in the same electrolyte is mandatory. This thesis will summarize our recent efforts towards developing 1st-row transition metal-based sulfides and phosphides for electrocatalytic water splitting under ambient conditions.
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Gamblin, Stuart David. "Chemical effects in the soft x-ray spectra of first row transition metal compounds." Thesis, Queen Mary, University of London, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243969.
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Sakurai, Hideo. "Theoretical study on the interaction between first row transition metal atom and oxygen molecule." 京都大学 (Kyoto University), 2002. http://hdl.handle.net/2433/150008.
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Pagano, Justin Kane. "Cyclopentadienyl Compounds of the First Row Transition Metals and Early Actinides: Novel Main-Group Bond Forming Catalysis and New Metallacycles." ScholarWorks @ UVM, 2017. http://scholarworks.uvm.edu/graddis/700.
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Cyclopentadienyl first row transition-metal compounds have been well studied since the 1950's, with the nearly ubiquitous CpFe(CO)2Me (FpMe) (Cp = η5-C5H5) being one of the first organometallics to be fully characterized. Despite the decades of study that have been poured into this complex, reactions between FpMe and primary phosphines have not been reported. Catalytic reactions with primary phosphines are generally understudied, including dehydrocoupling and P-C bond forming reactions such as hydrophosphination. A novel mechanism of dehydrocoupling and P-C bond formation that has received even more limited attention is α-elimination. This dissertation describes efforts in proving that FpMe is a competent catalyst for α-phosphinidene elimination through detailed trapping, labelling, and mechanistic studies. Additionally, the potential of α-elimination for the catalytic synthesis of phospholes from commercially available starting materials is shown, which is currently unknown.
In the course of α-elimination studies, it was found that [CpFe(CO)2]2 (Fp2) is a visible-light activated photocatalyst for a variety of main-group bond forming reactions, including amine borane dehydrocoupling, siloxane formation, silylcyanation, and the double hydrophosphination of terminal alkynes with secondary phosphines. By utilizing commercially available and inexpensive LED bulbs Fp2 was an active catalyst for these reactions, which avoided the use of expensive, hazardous, and energy inefficient mercury arclamps.
During studies to determine whether other cyclopentadienyl first row transition-metal compounds could catalyze α-elimination, it was found that CpCo(CO)I2 and Cp*Co(CO)I2 (Cp* = η5-C5Me5) are active catalysts for ammonia borane dehydrocoupling and transfer hydrogenation. These compounds are rare examples of cobalt compounds able to catalytically dehydrocouple amine boranes as well as catalyze a rare example of transfer hydrogenation that utilizes ammonia borane as a hydrogen source.
I will also describe my year of research at Los Alamos National Laboratory (LANL) working under Dr. Jaqueline Kiplinger. Two primary projects are described herein: the first of which is the use of phenylsilane as a safe, versatile method for the synthesis of the bis(cyclopentadienyl) actinide hydrides [Cp*2An(H)(µ-H)]2 from the bis-alkyl complexes Cp*2AnMe2. It is shown that these hydrides are excellent precursors for the synthesis of a variety of actinide metallocenes. Additionally, in the case of uranium, by adjusting the equivalents of phenylsilane added, the oxidation state and nuclearity of the hydrides synthesized can be altered. Second, efforts in synthesizing a variety of novel actinacycles including actinacyclopentadienes, actinacyclocumulenes, a novel uranacyclopropene, and actinacyclopentadienecyclobutabenzenes that display alternating aromatic and antiaromatic character.
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Maurice, Rémi. "Zero-field anisotropic spin hamiltonians in first-Row transition metal complexes : theory, models and applications." Doctoral thesis, Universitat Rovira i Virgili, 2011. http://hdl.handle.net/10803/37363.
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Aquest treball presenta l’estudi teòric de l’anisotropia magnètica en complexos de metalls de transició, combinant esquemes de càlcul multiconfiguracionals relativistes amb derivacions analítiques basades en la teoria del camp del lligand, el que permet racionalitzar a través de conceptes senzills els resultats quantitatius obtinguts i interpretar les propietats estudiades.
Es desenvolupa primer una metodologia per extreure els paràmetres d’anisotropia en complexos mononuclears de metalls de transició. El mètode es basa en assignar els resultats d’un càlcul ab initio d’alt nivell a un Hamiltonià model mitjançant la teoria d’Hamiltonians efectius. Aquesta metodologia s’aplica a complexos de Ni(II), Co(II) i Mn(III) i es comprova que és aplicable de forma general a complexos mononuclears.
S’estén després la metodologia a complexos binuclears, pels quals l’Hamiltonià model usualment utilitzat té una base menys rigorosa. L’Hamiltonià efectiu obtingut per un complex binuclear de Ni(II) introdueix una nova parametrització amb termes addicionals de les interaccions anisotròpiques en sistemes polinuclears. Es tracta d’un procediment universal que proporciona valors precisos i a més és capaç de contrastar la consistència interna dels Hamiltonians models existents.
Per racionalitzar les correlacions magnetoestructurals dels paràmetres d’anisotropia en complexos de Ni(II) i Mn(III), es descriuen els mecanismes electrònics bàsics en base a consideracions de la teoria del camp del lligand. Aquest procediment proporciona regles senzilles per augmentar l’anisotropia, que poden ser aplicades en el disseny de nous materials.
Finalment, s’estudien les interaccions anisotròpiques simètriques i antisimètriques en compostos binuclears de Cu(II), interaccions de gran importància per explicar les propietats d’alguns materials d’interès tecnològic. Les interaccions antisimètriques s’extreuen a partir de càlculs ab initio d’estructura electrònica per primer cop en aquest treball. Es concentra l’atenció d’aquesta part en dos sistemes: el conegut complex binuclear de Cu(II) amb quatre ponts acetat, i l’òxid de coure en el que recentment s’ha evidenciat una fase ferroelèctrica.
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Acuña-Parés, Ferran. "Theoretical study of water oxidation and reduction mechanisms by aminopyridine first row transition metal catalysts." Doctoral thesis, Universitat de Girona, 2016. http://hdl.handle.net/10803/398411.
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One of the major current scientific goals is the development of renewable energy sources. An effective alternative to fossil fuels consists in the conversion of the sunlight energy into chemical fuels. The molecular hydrogen from water is considered the most promising energy carrier. In the natural photosynthesis the solar energy is stored into the carbohydrate chemical bonds derived from water and CO2. The key step of this process is the photo-oxidation of H2O molecules into O2, which provides the protons and electrons needed to produce H2. A detailed knowledge of the reaction mechanisms results essential to enhance the catalytic performance and to ensure the compatibility of the water oxidation and proton reduction catalysts. In this thesis, the key steps of the water oxidation and proton reduction reactions catalyzed by a group of metal complexes and the catalysts structural features that benefit both processes are studied using computational toolsUn dels grans reptes actuals consisteix en el desenvolupament de fonts d'energia renovables. Una alternativa eficaç als combustibles fòssils consisteix en la conversió de l'energia solar en combustibles químics. L’hidrogen molecular provinent de l’aigua és considerat el portador d’energia més prometador. En la fotosíntesi natural l’energia solar és emmagatzemada en els enllaços químics dels carbohidrats obtinguts a partir d’aigua i CO2. L’etapa clau del procés és la foto-oxidació de l'aigua en O2, que aporta els protons i electrons necessaris per produir H2. El coneixement detallat del mecanisme de reacció resulta essencial per millorar el rendiment catalític i assegurar la compatibilitat dels catalitzadors d’oxidació de l’aigua i reducció de protons. En aquesta tesi, les etapes fonamentals del mecanisme de les reaccions d’oxidació de l’aigua o la reducció de protons catalitzades per un grup de complexos metàl·lics i les característiques estructurals dels catalitzadors que beneficien ambdues reaccions són estudiades utilitzant eines computacionals
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Bartholomew, C. R. "A Raman and electrochemical study of first row transition metal phthalocyanines and rare earth diphthalocyanines." Thesis, University of Strathclyde, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382264.
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Pierpont, Aaron. "Computational Study of Small Molecule Activation via Low-Coordinate Late First-Row Transition Metal Complexes." Thesis, University of North Texas, 2010. https://digital.library.unt.edu/ark:/67531/metadc28462/.
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Methane and dinitrogen are abundant precursors to numerous valuable chemicals such as methanol and ammonia, respectively. However, given the robustness of these substrates, catalytically circumventing the high temperatures and pressures required for such transformations has been a challenging task for chemists. In this work, computational studies of various transition metal catalysts for methane C-H activation and N2 activation have been carried out. For methane C-H activation, catalysts of the form LnM=E are studied, where Ln is the supporting ligand (dihydrophosphinoethane or β-diketiminate), E the activating ligand (O, NCH3, NCF3) at which C-H activation takes place, and M the late transition metal (Fe,Co,Ni,Cu). A hydrogen atom abstraction (HAA) / radical rebound (RR) mechanism is assumed for methane functionalization (CH4 à CH3EH). Since the best energetics are found for (β-diket)Ni=O and (β-diket)Cu=O catalysts, with or without CF3 substituents around the supporting ligand periphery, complete methane-to-methanol cycles were studied for such systems, for which N2O was used as oxygen atom transfer (OAT) reagent. Both monometallic and bimetallic OAT pathways are addressed. Monometallic Fe-N2 complexes of various supporting ligands (LnFe-N2) are studied at the beginning of the N2 activation chapter, where the effect of ligand on N2 activation in end-on vs. side-on N2 isomers is discussed. For (β-diket)Fe-N2 complexes, the additional influence of diketiminate donor atom (N(H) vs. S) is briefly addressed. The remainder of the chapter expands upon the treatment of β-diketiminate complexes. First, the activation and relative stabilities of side-bound and end-bound N2 isomers in monometallic ((β-diket)M-N2) and bimetallic ((β-diket)M-N2-M(β-diket)) first row transition metal complexes are addressed. Second, the thermodynamics of H/H+/H- addition to (β-diket)Fe-bound N2, followed by subsequent H additions up to release of ammonia, is discussed, for which two mechanisms (distal and alternating) are considered. Finally, the chapter concludes with partial distal and alternating mechanisms for H addition to N2 in bimetallic (β-diket)Fe-N2-Fe(β-diket) and (β-diket)M-N2-M(β-diket) (M = Ti,V,Fe), respectively.
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Perry, Jason Kendrick Goddard William A. "Alkane activation by first, second, and third row transition metal ions organometallic chemistry in the gas plate /." Diss., Pasadena, Calif. : California Institute of Technology, 1994. http://resolver.caltech.edu/CaltechTHESIS:11122009-152204878.
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Thesis (Ph. D.)--California Institute of Technology, 1994. UM #94-27,313.Advisor names found in the Acknowledgements pages of the thesis. Title from home page. Viewed 01/14/2010. Includes bibliographical references.
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Ouanounou, Sarah. "Investigation of Structural and Magnetic Properties of First and Second Row Transition Metals with N,N’,N and S,N,S Pincer-type Ligands." Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32212.
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This work began with the ambition of probing the application of pincer ligands to control the geometry and bonding environments of metal centers by employing the bis(imino) pyridine ligand scaffold and an assortment of transition metals, particularly silver and a variety of paramagnetic centers. The work was further extended to the investigation of the SNS tridentate thiolate ligand backbone, specifically the bis(methylthiomethyl) pyridine and bis(ethylthiomethyl) pyridine ligand frameworks with a similary array of transition metal centres. Along with the reports of novel coordination compounds and analysis of trends in bonding, computational chemistry was utilized to correlate the data obtained experimentally with computed models. Synthesis, characterization and computational studies are presented herein. Chapter 1 presents a brief history of the bis(imino) pyridine ligand as well as its synthesis and characterization. Chapter 2 presents a brief history of the S,N,S ligand as well as its synthesis and characterization. Chapter 3 presents the synthesis of a series of first row transition metal bromide-bis(imino) pyridine complexes along with their characterizations and an analysis of bonding trends. Chapter 4 presents the synthesis of a series of first row transition metal bromide-S,N,S ligand complexes along with their characterizations and an analysis of bonding trends. Chapter 5 presents a general conclusion to the work.
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Wood, Iain J. "Synthesis, characterisation and thermal analysis of some first row transition metal complexes and their application in polymer systems." Thesis, Edinburgh Napier University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295462.
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Cantalupo, Stefanie A. "Structural and electronic effects of mono- and bidentate perfluorinated alkoxide ligands in late first-row transition metal complexes." Thesis, Boston University, 2013. https://hdl.handle.net/2144/12725.
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Thesis (Ph.D.)--Boston University
PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.Seven homoleptic first-row transition metal complexes were prepared with the perfluoro-t-butoxide ligand with three- and four-coordinate geometry. The compounds were prepared via metathesis reactions with the form [M(OC4F9)3]-, M = Mn (1), Fe (2), Co (5), and Zn (7); [M(OC4F9)4]n-, M = Fe (4), Co (6); and the THF adducts [M(THF)(OC4F9)3]- M = Co (5-TBF), and Zn (7-THF). The complexes were synthesized and structurally characterized. Spectroscopic characterization with UV-vis, NMR, and IR will be discussed. Cyclic voltammetry studies of 5 and 6 in conjunction with UV-vis data show the presence of an equilibrium between the three- and four-coordinate complexes with ligand association and dissociation. Using the bidentate perfluorinated pinacolate ligand, ddfp, three complexes were prepared as [M(ddfp)2]2-, in which M =Fe (8), Co (9), and Zn (10). Complexes 8 and 9 have square-planar geometry and are high-spin. The magnetism was studied both in solution and the solid state. The combination of geometry and spin-state is rare for {M04} complexes and 9 is the first example of {C0O4} with this combination, and 8 is the second example of this combination in an {FeO4} system. A five-coordinate Co complex was also structurally characterized (9-OH2). A family of heteroleptic complexes of the form [Fe(X)(OC4F9)3]- in which X = Cl (11), Br (12), or pyridine (13), and [M(py)(ddfp)2]2- for M= Co (14), and Fe (15), were prepared and some were structurally characterized. Analytical data suggests the formation of an iron-amide complex, [Fe(HN(C6H5)(ddfp)2]3-, (16), capable of further reactivity. The synthesis, characterization, and preliminary reactivity studies will be discussed. Two iron aryloxide complexes were synthesized with the pentafluorophenolate ligand, [Fe(OArF)4]2-, (17) and [(OArF)3Fe(μ2-OArF)2Fe(OArF)3]2-, (18). The FeIII complex was formed as a result of presumed ligand oxidation and dissociation, highlighting the vulnerability of aryloxide ligands. A series of isotopically labeled compounds containing a short, strong hydrogen bond were prepared and characterized for neutron diffraction experiments. The compounds, [Cp2Co][D(OAr5)], (19) and d10-[Cp2Co][H(OAr')], (20), were prepared with the partially fluorinated OAr' ligand, bis-(3,5-trifluoromethyl)phenoxide. The synthesis and characterization of these compounds will be discussed.
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Shiota, Yoshihito. "Theoretical Study of C-H Bond Activation by First-Row Transition-Metal Oxide Ions in the Gas Phase." Kyoto University, 2001. http://hdl.handle.net/2433/150658.
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李鼎威 and Ting-wai Lee. "Self-assembly and crystal structure analysis of some first-row transition metal coordination polymers of 1,3-bis(4-pyridyl)propane." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2001. http://hub.hku.hk/bib/B31224660.
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Lee, Ting-wai. "Self-assembly and crystal structure analysis of some first-row transition metal coordination polymers of 1,3-bis(4-pyridyl)propane." Hong Kong : University of Hong Kong, 2001. http://sunzi.lib.hku.hk/hkuto/record.jsp?B23242322.
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Prina, Cerai Gabriele [Verfasser], Bill [Gutachter] Morandi, and Lukas J. [Gutachter] Gooßen. "First row transition metal catalyzed radical transformations / Gabriele Prina Cerai ; Gutachter: Bill Morandi, Lukas J. Gooßen ; Fakultät für Chemie und Biochemie." Bochum : Ruhr-Universität Bochum, 2018. http://d-nb.info/1161942025/34.
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Severn, John Richard. "Studies of d'5-d'9 first row transition metal and tin complexes containing 1-aza-allyl; or #beta#-diketiminato ligands." Thesis, University of Sussex, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.285127.
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Frantz, Eric Benjamin. "Synthesis, reactivity, and coordination chemistry relevant to the copolymerization of CO2 and epoxides by first row transition metal schiff base complexes." [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-2893.
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Baillie, Gordon M. "Preparation, spectral and magnetic studies on some first row transition metal complexes and an investigation into their performance as colourants for poly(vinyl chloride)." Thesis, Edinburgh Napier University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385997.
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Nouri, Hela. "Synthèse et caractérisations de propriétés optiques d’un nouveau ligand dérivé du Cyclen-azaxanthone : Applications potentielles dans la détection sélective du Zn2+." Thesis, Reims, 2013. http://www.theses.fr/2013REIMS018.
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Le présent travail concerne principalement l'élaboration d'un nouveau ligand en l'occurrence le cyclen-hydrazone, luminescent et efficace pour une détection relativement sélective de l'ion d'intérêt biologique, Zn2+. La synthèse du groupement azaxanthone à greffer sur le cyclen a été décrite. A partir de ces ligands, la complexation de zinc, a été traitée dans le but de développer une sonde optique sélective pour les ions métalliques de la première série de transition. Une étude photophysique associée à un travail de modélisation théorique en solution a plus particulièrement montré la formation de deux nouveaux complexes de zinc. Finalement, le contrôle des conditions de déprotection par hydrazinolyse du cyclen-glyoxal-azaxanthone, a montré que le motif azaxanthone puisse être maintenu dans la conception de nouveaux complexant de métaux de la première série de transitionThis study deals with the development of a new ligand: the cyclen-hydrazone, luminescent and effective for a relatively selective detection of biological ion, Zn2+. The synthesis of graft azaxanthone group to the cyclen was described. From these ligands zinc complexation was treated in order to develop an optical probe selective for the first row transition metals. A photophysic study associated with theoretical modeling work in solution, specifically showed the formation of two new zinc complexes. Finally, the monitoring of deprotection by hydrazinolysis of cyclen-glyoxal-azaxanthone, showed that the azaxanthone deprotection could be maintained in the design of new metals complexes of the first serie of transition metals
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Xu, Zhiqiang. "The magnetism and coordination chemistry of mononuclear and polynuclear complexes of copper(II) and other first row transition metal ions derived from open-chain diazine (N-N) ligands." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ36217.pdf.
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Lidster, Jon. "Design and synthesis of new metallo-organic complexes and their evaluation as anti-cancer agents : synthesis, characterisation and biological evaluation of novel, late first row transition metal Schiff base complexes, as anti-cancer metallopharmaceuticals." Thesis, University of Bradford, 2011. http://hdl.handle.net/10454/5679.
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This work is concerned with the design and synthesis of the cheap, late first row transition metal complexes of Schiff base ligand systems. The prepared complexes readily afford systematic variation in order to probe potency and understand the role of metal, chelating ligands and anionic ligands when carrying out their cytotoxic effect. This study has lead to a better understanding of the action of these classes of complex and will be used to direct the design of new anti-cancer metallopharmaceuticals going forward. This thesis details the synthesis of a library of Schiff base macroacyclic ligands and their novel late first row transition metal complexes with varying anionic counterparts. The creation of a library with several degrees of variability provides a wide array of parameters to afford subtle variation in structure and chemistry e.g. denticity, co-ordination mode, chelate hole size, metal centred redox potentials, hydrolysis rates, co-ordinative saturation, lipophilicity, solubility and more. Complexation of the ligands was carried out by the free ligand and a novel macroacyclic metal template approach using the cheap late first row transition metal salts of Cobalt (II), Nickel (II), Copper (II) and Zinc (II) plus one Ru (III) complex. Structural studies of the 80 generated complexes was carried out by vibrational spectroscopy, elemental analysis, mass spectrometry, magnetic susceptibility and NMR. Single crystal X-ray structures have been determined with 20 reported in this thesis. All ligands act as tridentate ligands in all except one case to form monomeric distorted trigonal-bipyramidal, square-pyramidal or octahedral structures. In the case of zinc nitrate, the ligand L2PhMe acts as a tetradentate ligand to give a distorted octahedral structure. Paramagnetic NMR and solution magnetic susceptibility of paramagnetic complexes was achieved by the Evans NMR method and analysis of the solution NMR showed that L2R and L3R ligands display 2-fold symmetry and are likely either tetradentate in solution or a fast exchange between imine N-donar sites is occurring even down to -65°C. The majority of the resulting complexes of L1R were screened against a panel of three cancer cell lines. Several categories of complex were able to afford structure activity relationships. It was discovered that the ligand is indeed essential for activity of the metal salts against the panel of cell lines and it was largely discovered that the variation in 'tail group' and anionic coordinating ligands played little role in providing a dramatic variation in activity of the metal salt. In general all L1R complexes displayed moderate cytotoxicity showing a trend in activity with respect to the metal in the order RuIII≈CoII>CuII≈ZnII>NiII, over a 6 day exposure to the three cell panel RuIII was shown to be the most potent metal of the L1R series providing IC50 values of 4.6 (0.7) and 7.5 (1.2) μM against the DLD-1 and H460 cell lines respectively, which is Ca. 4.6 and 15 times less potent than cisplatin to the same cell panel respectively. RuIII was also discovered to be the only metal to provide an IC50 value from a 1 hour exposure to the DLD-1 cell panel. The value of 20.4 (3.5) μM is a moderate figure but again Ca. 10 fold less potent than cisplatin for the same test. The L2R and L3R complexes could not be screened by the same comprehension due to their low solubilities. However the lone screen that was possible from the very sparingly soluble complex [CuCl2(L3Bui)] gave the most exciting result and most potent complex of this thesis. After a 6 day exposure, [CuCl2(L3Bui)] gave IC50 values of 4.3 (0.1) and 2.9 (0.1) μM against the DLD-1 and H460 cell lines respectively. These values are merely 4 and 6 fold more than Cisplatin to the same cell lines respectively and demonstrates the potential of this class of complex as cytostatic agents. Further studies utilising a semi-quantitative DNA damaging assay, demonstrated that all first row complexes can damage DNA when in the presence of hydrogen peroxide, with the exception of ZnII complexes. CoII appeared to afford the greatest DNA damage with the most intsense bands for double strand breaks and the CuII complex of the ligand L3Bui also demonstrated a greater DNA damage as opposed to its L1Bui analogue.
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Mercadé, Espinosa Elisabet. "Nitrogen-based ligands for iron, zinc and cobalt catalyzed selective processes." Doctoral thesis, Universitat Rovira i Virgili, 2015. http://hdl.handle.net/10803/586282.
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Aquesta tesi doctoral aborda la síntesi de nous lligands polidentats, i la seva posterior coordinació amb metalls de la primera sèrie de transició per formar catalitzadors efectius en les reaccions de transferència d'hidrogen asimètrica, hidrogenació i acoblament de CO2 amb epòxids. En el capítol 3 es descriu la síntesi de nous lligands quirals tipus PNNP. Els corresponents complexos de ferro es van obtenir en bons rendiments, i les seves estructures de raigs-X van ser resoltes. La reacció de transferència d'hidrogen asimètrica de diversos substrats cetona es va dur a terme amb un sistema catalític compost per lligands PNNP/ Fe3 (CO)12 obtenint de moderades a elevades conversions i enantioselectivitats.
En el capítol 4 es descriu la síntesi d'una nova família de lligands tipus N2O2, N2NH2, N4 i N4 (NH). Els corresponents complexos de zinc es van obtenir en bons rendiments i les seves estructures de raigs-X van ser resoltes. Els complexos de zinc resultants van catalitzar la reacció d'acoblament de CO2 amb epòxids terminals i interns, sent el complex de zinc-N4 el més actiu de la sèrie. Aquest mateix complex es va poder reciclar fins a cinc vegades sense pèrdua significativa d'activitat, el que va provar la robustesa del mateix.
En el Capítol 5 es descriu la síntesi de lligands C ^ N ^ C de tipus pincer. Posteriorment, es van coordinar a cobalt, observant la coordinació del centre de cobalt únicament a la piridina del lligand, deixant els imidazols del lligant sense coordinar al centre metàl·lic. Posteriorment es va estudiar l'activitat d'aquests complexos en la hidrogenació asimètrica de diverses cetones.Esta tesis doctoral aborda la síntesis de nuevos ligandos polidentados, y su posterior coordinación con metales de la primera serie de transición para formar catalizadores efectivos en las reacciones de transferencia de hidrógeno asimétrica, hidrogenación y acoplamiento de CO2 con epóxidos. En el Capítulo 3 se describe la síntesis de nuevos ligandos quirales tipo PNNP. Los correspondientes complejos de hierro se obtuvieron en buenos rendimientos, y sus estructuras de rayos-X fueron resueltas. La reacción de trasferencia de hidrógeno asimétrica de diversos sustratos cetona se llevó a cabo con un sistema catalítico compuestos por ligandos PNNP/Fe3(CO)12 obteniendo de moderadas a elevadas conversiones y enantioselectividades. En el capítulo 4 se describe la síntesis de una nueva familia de ligandos tipo N2O2, N2NH2, N4 y N4(NH). Los correspondientes complejos de zinc se obtuvieron en buenos rendimientos y sus estructuras de rayos-X fueron resueltas. Los complejos de zinc resultantes catalizaron la reacción de acoplamiento de CO2 con epóxidos terminales e internos, siendo el complejo de zinc-N4 el más activo de la serie. Este mismo complejo se pudo reciclar hasta cinco veces sin pérdida significativa de actividad, lo que probó la robusteza del mismo. En el Capítulo 5 se describe la síntesis de ligandos C^N^C de tipo pincer. Posteriormente, se coordinaron a cobalto, observando la coordinación del centro de cobalto únicamente a la piridina del ligando, dejando los imidazoles del ligando sin coordinar al centro metálico. Posteriormente se estudió la actividad de estos complejos en la hidrogenación asimétrica de varias cetonas.
This thesis deals with the synthesis of new polydentate ligands, and further coordination with first-row transition metals to form effective catalysts in the asymmetric transfer hydrogenation and asymmetric hydrogenation of ketones and coupling of CO2 with epoxides. In Chapter 3 the synthesis of new chiral PNNP ligands is described. The corresponding iron complexes were obtained in good yields, and their X-ray structures were elucidated. The asymmetric transfer hydrogenation of a variety of ketones was carried out with the PNNP/Fe3(CO)12 catalytic system obtaining moderate to high conversions and enantioselectivities. In Chapter 4 the synthesis of a new family of ligands containing N2O2, N2NH2, N4 and N4 (NH) ligand scaffolds is described. The corresponding zinc complexes were obtained in good yields and their X-ray structures were elucidated. The resulting zinc complexes catalyzed the coupling of CO2 with terminal and internal epoxides, being the zinc-N4 complex the most active of the series. This catalytic system could be also recycled up to five times without significant loss of activity, which demostrated the robustness of the system. Chapter 5 describes the synthesis of C^N^C pincer type ligands. Subsequently, their coordination to cobalt was evaluated, observing the coordination of the cobalt center to the pyridine of the C^N^C ligand maintaining the imidazole moieties uncoordinated. Subsequently the activity of these complexes was studied in the asymmetric hydrogenation of various ketones.
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Nduwimana, Alexis. "First principle calculation of missing-row reconstructed (110) surfaces of noble metals." DigitalCommons@Robert W. Woodruff Library, Atlanta University Center, 2001. http://digitalcommons.auctr.edu/dissertations/3771.
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The purpose of this thesis is to calculate the surface energy for the (1 x n) reconstructed (110) surfaces of noble metals. The calculation was done using a code called VASP (Vienna Ab-initio Simulation Package). The code uses the Density Functional Theory to study the electronic structures of materials. By computing the surface energy of the missing-row reconstructed (110) surfaces of Au, we observe that the (1x2) structure has the lowest energy. For Pt, the (1x2) and the (1x3) structures have close surface energies. For Ir, the (331) configuration is found to have the lowest energy. The multilayer relaxation of those noble metal surfaces and the surface energy exhibited the same behavior. The change in the charge projection of the top layer can be used to explain the surface energy trend.
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Feng, Yongjia. "First principles studies of transition metal surfaces : the effect of an external field on surface electronic properties and surface energetics /." View Abstract or Full-Text, 2003. http://library.ust.hk/cgi/db/thesis.pl?PHYS%202003%20FENG.
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Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2003.Includes bibliographical references (leaves 106-110). Also available in electronic version. Access restricted to campus users.
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MUDARMAH, KHALIL. "REACTIVITY OF MOLYBDENUM AND TUNGSTEN SULFIDO COMPLEXESWITH FIRST-SERIES TRANSITION METALS." Cleveland State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=csu1566563467202265.
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Yamagishi, Shuichi. "First principles studies of aromatic adsorbates on transition metals : structure, energetics and diffusion." Thesis, University of Cambridge, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.620466.
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