Tesis: "Organic-inorganic c"

1

Stein, Natalia. "Spectroscopic and electrochemical studies of Shewanella oneidensis cytochrome c nitrite reductase, and improving c-heme expression systems". Thesis, The University of Wisconsin - Milwaukee, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3685085.

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In this work the redox properties of cytochrome c nitrite reductase (CcNiR), a decaheme homodimer that was isolated from S. oneidensis, were determined in the presence and absence of the strong-field ligands cyanide and nitrite. Four hemes per CcNiR protomer are hexa-coordinate with tightly bound axial histidines, while the fifth (active site) has one tightly bound lysine and a distal site that can be open, or contain exogenous ligands such as the substrate nitrite. Controlled potential electrolysis in combination with UV/visible absorption (UV-vis) and electron paramagnetic resonance (EPR) spectroscopies allowed for assignment of all heme midpoint potentials under each set of conditions. The studies show that the active-site heme is the first to be reduced under all conditions. The midpoint redox potential of that heme shifts approximately 70mV to the positive upon binding a strong field ligand such as nitrite or cyanide. When controlled potential electrolysis was carried out in the presence of nitrite, a concerted two electron reduction was observed by UV-vis, and a {Fe(NO)}⁷ reduced product was revealed in EPR. In addition, an asymmetry in ligand binding between active sites was revealed. This information is relevant for the interpretation of planned and ongoing mechanistic studies of CcNiR.

Over-expression, partial purification and characterization of another S. oneidensis multiheme enzyme, known as octaheme tetrathionate reductase (OTR), is also described herein. Though of unknown cellular function, OTR was previously reported to have tetrathionate reductase activity, in addition to nitrite and hydroxylamine reductase activities. The new results indicate that the expression of OTR has no effect on tetrathionate or nitrite reductase activities in the whole cell lysate, and only hydroxylamine reductase activity was substantially elevated in the overexpressing bacteria. OTR was stable in buffered solutions, but substantial activity loss during all attempts at column chromatography was a major obstacle to the complete purification. OTR also proved quite hydrophobic, so possible membrane association should be considered in future attempts to purify this protein.

Finally, this dissertation also reports attempts to improve S. oneidensis' ability to express foreign proteins. Though ideally suited to expressing c-hemes, it proved difficult to express carboxy his-tagged proteins in S. oneidensis because of persistent tag degradation. Attempts to knock out lon protease, a cytoplasmic carboxypeptidase, as well as the result of redirecting ccNiR from the SecA to the possibly more protected signal particle recognition (SRP) secretion pathway, are described.

Iron heme cofactors are single-electron transport moieties that play a crucial role in respiration. While oxygen is the electron acceptor of choice in aerobic atmospheres, microorganisms that live in anaerobic environments utilize other molecules with similarly high reduction potentials. S. oneidensis can utilize numerous terminal electron acceptors, including nitrite, dimethylsulfoxide and even uranium, thanks to a particularly rich array of multi c-heme respiratory proteins. Understanding of how the midpoint potentials and heme arrangements within the proteins influence these exotic respiratory processes is of interest in the fields of bioremediation and fuel development.

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2

Fritze, Lars [Verfasser] y Holger [Gutachter] Helten. "Ways to Novel Inorganic-Organic Hybrid Materials Applying New B–C Bond Formation Strategies / Lars Fritze ; Gutachter: Holger Helten". Würzburg : Universität Würzburg, 2021. http://d-nb.info/1238018483/34.

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3

Gowda, Anitha Shankaralinge. "HYDROGENATION AND HYDROGENOLYSIS OF FURAN DERIVATIVES USING BIPYRIDINE-BASED ELECTROPHILIC RUTHENIUM(II) CATALYSTS". UKnowledge, 2013. http://uknowledge.uky.edu/chemistry_etds/29.

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The catalytic activity of ruthenium(II) bis(diimine) complexes cis-[Ru(6,6′-Cl2bpy)2(OH2)2](Z)2 (2, Z = CF3SO3; 3, Z = (3,5-(CF3)2C6H3)4B ,i.e. BArF), cis-[Ru(4,4′-Cl2bpy)2(OH2)2](Z)2 (4, Z = CF3SO3; 5, Z = BArF) and cis-[Ru(bpy)2(PR3)(OH2)](CF3SO3)2 (7, bpy = 2,2’-bipyridine, PR3 = P(C6H4F)3; 8, bpy = 2,2-bipyridine, PR3 = PPh3; 9, bpy = 4,4’-dichloro-2,2’-bipyridine, PR3 = PPh3; 10, bpy = 4,4’-dimethyl-2,2’-bipyridine, PR3 = P(C6H4F)3) for the hydrogenation and hydrogenolysis of furfural (FFR), furfuryl alcohol (FFA) and 5-hydroxymethylfurfural (HMF) was investigated. The compounds 2-5 are active and highly selective catalysts for the hydrogenation of FFR to FFA. Using 2 as catalyst at 100 °C, hydrogenation of FFR proceeded to high conversion (≥98%) and with 100% selectivity to FFA in 2 h. The catalyst cis-[Ru(6,6′-Cl2bpy)2(OH2)2](CF3SO3)2 (2) also showed some activity for hydrogenolysis of FFR and FFA at 130 °C in ethanol, giving up to 25% of 2-methylfuran (MF) yield. The catalyst 3 alsodisplayed high catalytic activity for the hydrogenation of FFA to tetrahydrofurfuryl alcohol. Catalysts 7-10 are also active towards the hydrogenation of furfural (FFR) in NMP giving >90% FFR conversion with 100% selectivity for furfuryl alcohol (FFA) in 12 h. Compounds 7-10 are active C-O bond hydrogenolysis catalysts in presence of bismuth halide Lewis acids. For example, hydrogenolysis of FFA in the presence of 1 mol% of catalyst cis-[Ru(4,4’-Cl2bpy)2(PPh3)(OH2)](CF3SO3)2 (9) and 20 mol% bismuth bromide at 180 °C/51 atm H2 pressure gave >96% conversion of FFA and 55% MF yield. Compounds 7-10 in the presence of bismuth halides, showed almost 100% conversion of HMF with a very high selectivity (65-72%) for 2,5-DMF, along with 10-12% of MF, and trace amount of 5-methylfurfural (MeFFR). In order to test the activity of ruthenium hydrides towards the C-O bond hydrogenation and hydrogenolysis of HMF, series of monocationic ruthenium complexes cis-[Ru(bpy)2(PR3)(H)](CF3SO3) (12, bpy = 2,2’-bipyridine, PR3 = P(C6H4F)3; 13, bpy = 2,2-bipyridine, PR3= PPh3; 14, bpy = 4,4’-dimethyl-2,2’-bipyridine, PR3= P(C6H4F)3) were prepared. The hydrogenation of HMF using catalysts 12-14, produced 70-72% of 2,5-DMF and 11% MF, suggesting that ruthenium hydrides are active and efficient catalysts for HMF hydrogenation.

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4

Wieland, Florian D. C. [Verfasser], Metin [Akademischer Betreuer] Tolan y Heinz [Akademischer Betreuer] Rehage. "Formation of organic and inorganic thin films at the aqueous solution-gas interface / Florian D. C. Wieland. Betreuer: Metin Tolan. Gutachter: Heinz Rehage". Dortmund : Universitätsbibliothek Dortmund, 2012. http://d-nb.info/1098312848/34.

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5

Wieland, Florian [Verfasser], Metin [Akademischer Betreuer] Tolan y Heinz [Akademischer Betreuer] Rehage. "Formation of organic and inorganic thin films at the aqueous solution-gas interface / Florian D. C. Wieland. Betreuer: Metin Tolan. Gutachter: Heinz Rehage". Dortmund : Universitätsbibliothek Dortmund, 2012. http://nbn-resolving.de/urn:nbn:de:101:1-201604272960.

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6

Banks, Surya R. "Organometallic Materials: Ferroceno[c]thiophenes and 1,2-Bisthienylmetallocenes". UKnowledge, 2016. http://uknowledge.uky.edu/chemistry_etds/68.

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Development of synthetic routes toward two general organometallic frameworks was undertaken. The first project involved synthetic attempts of substituted and unsubstituted ferroceno[c]thiophene while the second one was the synthesis of 1,2-dithienylmetallocenes. The long-term goal of this work is to lay the foundations for study of electronic, electrochromic, redox, and optical properties of thiophene-based materials integrated with organometallic systems such as ferrocene, ruthenocene and cymantrene. The synthetic pathway for the target molecule in the first project involved converting 1,2-bis(hydroxymethyl)ferrocene to 1,2-bis(thiouroniummethyl)ferrocene with thiourea under acidic conditions. Refluxing the salt in base followed by acidification resulted in 1,2-bis(mercaptomethyl)ferrocene, which is oxidized to the cyclic ferroceno[d]-1,2-dithiane. Ring contraction of cyclic dithiane gave the thioether, ferroceno[c]-2,5-dihydrothiophene. Periodate oxidation of the thioether gave ferroceno[c]-2,5-dihydrothiophene-S-oxide (1), a potential precursor for ferroceno[c]thiophene via Pummerer dehydration. Attempts to dehydrate 1 and to trap the resulting thiophene in situ indicated instability of the target compound. Synthesis of ferroceno[c]thiophene with electron-donating as well as electron-withdrawing substituents at the 2,5-positions of the thiophene ring was attempted. 1,2–Dithienylethenes and their derivatives have gained increased attention due to their exceptional photochromic property. They tend to be thermally irreversible but photochemically reversible, which is a vital for their potential use in optical memories, switches and other optoelectronic applications. Inspiration of the second project was that incorporation of 1,2-dithienyl systems into metallocenes would enhance the general properties of the molecule, including stability, fatigue resistance, solid-state reactivity and higher sensitivity. 1,2-Dithienylferrocene was successfully synthesized. The synthetic pathway for 1,2-dithienylferrocene involved the reaction of α-bromo-3-acetyl-2,5-dimethylthiophene (1) with ethyl 4-(2,5-dimethylthiophen-3-yl)-3-oxobutanoate (2) to give 2,3-diarylcyclopent-2-en-1-one (3). Compounds 1 and 2 were synthesized following literature methods. Compound 3 was then converted to its cyclopentadienide form by first reducing the ketone to alcohol using LAH, followed by dehydration and then deprotonation of the substituted cyclic diene using butyllithium to give 1,2-bis(2,5-dimethylthiophene)-2,4-cyclopentadien-1-yl)lithium (4). [Fe(fluorenyl)(Cp)] was then used as a transfer reagent and reacted with 4 to yield the target compound.

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7

Gazda, Daniel Bryan. "Development of colorimetric solid Phase Extraction (C-SPE) for in-flight Monitoring of spacecraft Water Supplies". Washington, D.C. : Oak Ridge, Tenn. : United States. Dept. of Energy. Office of Science ; distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2004. http://www.osti.gov/servlets/purl/835309-K3fMzj/webviewable/.

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8

Nambukara, Wellala Nadeesha P. "Synthesis and Catalytic Activities of Nickel Complexes Bearing Flexible Tridentate Ligands". University of Cincinnati / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1491561548324255.

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9

Kitschke, Philipp, Marc Walter, Tobias Rüffer, Heinrich Lang, Maksym V. Kovalenko y Michael Mehring. "From molecular germanates to microporous Ge@C via twin polymerization". Universitätsbibliothek Chemnitz, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-200917.

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Four molecular germanates based on salicyl alcoholates, bis(dimethylammonium) tris[2-(oxidomethyl)phenolate(2-)]germanate (1), bis(dimethylammonium) tris[4-methyl-2-(oxidomethyl)phenolate(2-)]germanate (2), bis(dimethylammonium) tris[4-bromo-2-(oxidomethyl)phenolate(2-)]germanate (3) and dimethylammonium bis[2-tert-butyl-4-methyl-6-(oxidomethyl)phenolate(2-)][2-tert-butyl-4-methyl-6-(hydroxymethyl)phenolate(1-)]germanate (4), were synthesized and characterized including single crystal X-ray diffraction analysis. In the solid state, compounds 1 and 2 exhibit one-dimensional hydrogen bonded networks, whereas compound 4 forms separate ion pairs, which are connected by hydrogen bonds between the dimethylammonium and the germanate moieties. The potential of these compounds for thermally induced twin polymerization (TP) was studied. Germanate 1 was converted by TP to give a hybrid material (HM-1) composed of phenolic resin and germanium dioxide. Subsequent reduction with hydrogen provided a microporous composite containing crystalline germanium and carbon (Ge@C – C-1, germanium content ∼20%). Studies on C-1 as an anode material for Li-ion batteries revealed reversible capacities of ∼370 mA h gGe@C−1 at a current density up to 1384 mA g−1 without apparent fading for 500 cycles
Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich

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10

Krasia, Theodora. "Synthese und kolloidale Eigenschaften neuartiger Blockcopolymere mit [beta]-Dicarbonyl-Einheiten [Beta-Dicarbonyl-Einheiten] Synthesis and colloidal properties of a novel type of block copolymers bearing [beta]-dicarbonyl [beta-dicarbonyl] residues /". Phd thesis, [S.l. : s.n.], 2003. http://pub.ub.uni-potsdam.de/2003/0021/krasia.pdf.

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11

Kitschke, Philipp, Marc Walter, Tobias Rüffer, Andreas Seifert, Florian Speck, Thomas Seyller, Stefan Spange et al. "Porous Ge@C materials via twin polymerization of germanium(II) salicyl alcoholates for Li-ion batteries". Universitätsbibliothek Chemnitz, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-197302.

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The germylenes, germanium(II) 2-(oxidomethyl)phenolate (1), germanium(II) 4-methyl-2-(oxidomethyl)phenolate (2) and germanium(II) 4-bromo-2-(oxidomethyl)phenolate (3) were synthesized and their thermally induced twin polymerization to give organic–inorganic hybrid materials was studied. The compounds 1–3 form oligomers including dimers, trimers and tetramers as a result of intermolecular coordination of the benzylic oxygen atom to germanium. The structural motifs were studied by single crystal X-ray diffraction analysis and DFT-D calculations. Thermally induced twin polymerization of these germylenes gave hybrid materials based on germanium-containing phenolic resins. Carbonization of these resins under reductive conditions resulted in porous materials that are composed of germanium and carbon (Ge@C materials), while oxidation with air provided non-porous germanium dioxide. The porous Ge@C materials were tested as potential anode materials for rechargeable Li-ion batteries. Reversible capacities of 540 mA h g−1 were obtained at a current density of 346 mA g−1 without apparent fading for 100 cycles, which demonstrates that germanium is well accessible in the hybrid material
Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich

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12

Deb, Tapash K. "Bioinspired Redox Active Pseudotetrahedral Ni(II) Thiolate and Phenolate Complexes: Synthesis, Characterization, Alkylation Kinetics and Molecular Oxygen Activation". Ohio University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1377256181.

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13

Goldmann, Michel. "Etude, par diffusion neutronique de l'insertion du tetrahydrofuranne dans le graphiture csc : :(24) et des transitions structurales dans les composes intercalaires cs(thf)::(x)c::(24)". Paris 7, 1988. http://www.theses.fr/1988PA077061.

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Des composes ternaires graphite-cesium-tetrahydrofuranne (thf) sont formes par reaction du thf gazeux avec csc::(24). L'insertion du thf a ete suivie in situ en temps reel. On observe que l'insertion se produit en deux etapes successives, conduisant dans un premier temps a un compose pauvre cs(thf)::(0,9)c::(24), puis au compose riche final cs(thf)::(1,7)c::(21). Le passage de la phase riche a la phase pauvre est reversible par cryopompage du thf qui est, dans tous les cas, couche parallelement aux feuillets graphitiques. Description des deux phases et de leurs transformations

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14

Nafis, Mohammed. "Etude spectroscopique de l'hypericine et de ses complexes métalliques en relation avec leur activité photodynamique". Grenoble 1, 1993. http://www.theses.fr/1993GRE10117.

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L'hypericine, pigment naturel dont la phototoxicite est remarquable, pourrait etre utilisee en phototherapie. La deprotonation a ph>10 se traduit par un effet bathochrome sur le spectre d'absorption. La complexation par un des cations des metaux (al, gd, tb, fe, cu) dans la region ou se situent les groupes carbonyle et hydroxyle s'accompagne, de maniere analogue, d'un deplacement de ce spectre vers le rouge. Nous avons determine les constantes de formation des complexes metalliques de l'hypericine du type (hyp-m) ou (hyp-m2). Les proprietes spectroscopiques et photophysiques des complexes metalliques de l'hypericine ont ete etudiees en liaison avec leurs proprietes phototoxiques. L'etude cinetique de l'oxydation du 1,3-diphenylisobenzofuranne montre que les complexes metalliques de l'hypericine photosensibilisent avec un bon rendement la formation d'oxygene singulet. L'irradiation d'une solution aeree d'hypericine, conduit aussi a la formation du radical anion superoxyde a partir de la reduction de l'oxygene par une semiquinone. Cette formation sensibilisee a ete demontree a l'aide de la reduction du cytochrome c. Les complexes metalliques de l'hypericine peuvent etre utilises comme agents phototherapeutiques

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15

Fritze, Lars. "Ways to Novel Inorganic-Organic Hybrid Materials Applying New B–C Bond Formation Strategies". Doctoral thesis, 2021. https://doi.org/10.25972/OPUS-24217.

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π-Conjugated oligomers and polymers with tricoordinate boron centers incorporated into the main chain have attracted considerable attention as the interaction of the vacant p orbital on boron with an adjacent π system of the chain leads to conjugated materials with intriguing optical and electronic properties. This enables applicability in organic electronics and optoelectronics (OLEDs, OFETs, photovoltaics) or as sensory materials. The potential of our B–C coupling protocol using metal-free catalytic Si/B exchange condensation is demonstrated by the synthesis of a series of π-conjugated monodisperse (het)aryl oligoboranes. Variation of the (het)aryl moieties allowed for tunability of the optoelectronic properties of the materials. Additionally, catalytic C–C cross-coupling strategies were applied to synthesize oligofuryl-based mono- and bisboranes, as well as polymers. These studies led to very robust and highly emissive compounds (f up to 97 %), which allow for tuning of their emission color from blue to orange. Furthermore, this work includes investigations of reaction routes to a kinetically stabilized tetraoxaporphyrinogen. Being a key aspect of this work, a full investigation of the mechanism of the catalytic Si/B exchange was carried out. Additionally, this work presents the use of borenium cations to perform B–C coupling via intermolecular electrophilic borylation. Similar to the Si/B exchange, this route is capable of giving access to diaryl(bromo)boranes
π-konjugierte Oligomere und Polymere mit dreifach koordinierten Bor-Zentren, die in die Hauptkette eingebaut sind, haben große Aufmerksamkeit erregt, da die Wechselwirkung des vakanten p-Orbitals am Bor mit dem π-System der Kette zu konjugierten Materialien mit faszinierenden optischen und elektronischen Eigenschaften führt. Dies ermöglicht die Anwendbarkeit in organischer Elektronik und Optoelektronik (OLEDs, OFETs, Photovoltaik) oder als sensorische Materialien. Das Potenzial unseres B–C-Kupplungsprotokolls unter Verwendung der metallfreien katalytischen Si/B-Austauschskondensation wird durch die Synthese einer Reihe von π-konjugierten monodispersen (Het)aryl-Oligoboranen demonstriert. Durch Variation der (Het)aryl-Anteile konnten die optoelektronischen Eigenschaften der Materialien eingestellt werden. Zusätzlich wurden katalytische C–C-Kreuzkupplungsstrategien angewandt, um Oligofuryl-basierte Mono- und Bisborane sowie Polymere zu synthetisieren. Diese Untersuchungen führten zu sehr robusten und stark emittierenden Verbindungen (f bis zu 97 %), die die Einstellung ihrer Emissionsfarbe von blau bis orange ermöglichen. Weiterhin beinhaltet diese Arbeit Untersuchungen von Reaktionswegen zu einem kinetisch stabilisierten Tetraoxaporphyrinogen. Als ein Schlüsselaspekt dieser Arbeit wurde eine vollständige Untersuchung des Mechanismus des katalytischen Si/B-Austauschs durchgeführt. Zusätzlich wird in dieser Arbeit die Verwendung von Borenium-Kationen zur Durchführung von B–C-Kupplungen über intermolekulare elektrophile Borylierungen vorgestellt. Ähnlich wie beim Si/B-Austausch kann dieser Weg genutzt werden, um Zugang zu Diaryl(bromo)boranen zu geben

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16

Gonzalez, Jorge Alberto. "Part I. Spin-state isomerism in crystalline (trifluoromethanesulfonato)(meso-tetraphenylporphinato)iron(III). Part II. Toward refined model compounds for the cytochrome c oxidase active site: A new picket-fence porphyrin with short imidazole pickets". Thesis, 1991. http://hdl.handle.net/1911/16443.

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Part I. The unsolvated porphyrin compound (Fe$\sp{\rm III}$(TPP)(OSO$\sb2$CF$\sb3$)) has been structurally characterized by single-crystal X-ray diffraction in a monoclinic phase at 293 K and in a triclinic phase at 293, 188 and 103 K. While only one type of molecular site is found in the monoclinic phase, the temperature-dependent structural parameters and magnetic susceptibility data (5.82 $\mu\sb{\rm B}$ at 293 K; 4.86 $\mu\sb{\rm B}$ at 20 K) together indicate the existence of two crystallographically and magnetically distinct spin-admixed crystal lattice sites in the triclinic phase. One site (molecule 1) is unique in that its structure is temperature dependent, whereas the second site (molecule 2) has a structure which is essentially independent of temperature. This distinct site assignment has been further investigated by Mossbauer and EPR spectroscopies which suggest different spin ground states for molecules 1 and 2. This triclinic phase is also the first report of molecule pairs of the same porphyrin complex interacting in very different ways in the same crystal lattice in that molecule 1 pairs form $\pi$-$\pi$ dimers, whereas molecule 2 pairs do not. Part II. A new binucleating picket-fence porphyrin ligand, 5,10,15,20-Tetrakis (o-4-methylimidazole-5-ethylcarboxyl-2-oxy)phenyl) porphyrin, N$\sb4$-PH$\sb2$, has been synthesized and characterized to be used eventually as a vehicle to study the structure, function and reactivity patterns of the active site of cytochrome c oxidase. The enzyme itself contains an (Fe(porphyrin)$\cdots$Cu) binuclear active site of unknown structure. The properties which set N$\sb4$-PH$\sb2$ apart from other binucleating picket-fence porphyrin ligands previously prepared as active site ligating molecules are the four authentic imidazole nitrogen donor atoms in the potential binding site for the Cu center and a separation between potential metal binding sites of only 3.5 to 4.0 A, made possible by the ligand's exceptionally "short" picket-fence arms derived from imidazole-ether linkages.

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17

Lu, JIASHENG. "N^N- AND N^C CHELATE FOUR-COORDINATE ORGANOBORON COMPOUNDS: SYNTHESIS, PROPERTIES AND APPLICATIONS". Thesis, 2013. http://hdl.handle.net/1974/7913.

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This thesis concerns the synthesis of N^N- and N^C-chelate four coordinate organoboron compounds and the investigation of their photophysical and photochemical properties. The preparation of a novel BODIPY derivative possessing unusual dual emissive property has been accomplished. The origin of the dual emission was determined through a detailed investigation. The use of the new BODIPY compound as a highly effective surface ligand for achieving highly uniform and monodispersed PbS nanoparticles has been demonstrated. Electronic communication between BODIPY ligands at the nanoparticle surface and the PbS core has also been established. The incorporation of BODIPY-bearing PbS nanoparticles into a simple photovoltaic device was shown to enhance the device’s performance. The preparation of two new BODIPY molecules decorated with either BMes2(vinyl) units or N^C-chelate boryl units has been achieved. Substitution at the meso or the 2,6-positions of the BODIPY core resulted in a significant shift of the emission energy with respect to that of the parent compound. In contrast, replacement of the fluorine substituents with BMes2-vinyl or B(ppy)Mes2-alkynyl groups did not affect the emission wavelength. Both molecules exhibited excellent photophysical properties in solution and the solid state. The BMes2(vinyl) unit greatly enhances BODIPY fluorescence efficiency in a PMMA matrix. Meanwhile, the photoreactivity of the N^C-chelate boryl unit is switched off completely by the BODIPY ligand via intramolecular energy transfer. A new class of N^C-chelate organoboron compounds have been synthesized. This class of compounds has been found to display unprecedented photo-reactivity, namely, photo-elimination reactions, which enabled the synthesis of new B-N substituted phenanthrene compounds in high conversion yields. The new B-N substituted phenanthrene compounds exhibited excellent absorptive and emissive properties with potential applications in optoelectronic devices.
Thesis (Ph.D, Chemistry) -- Queen's University, 2013-04-22 15:53:14.091

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18

Yen, Yu-Ling y 顏郁玲. "Effects of dietary organic and inorganic manganese source interact with vitamin C on the growth and immune response of grouper, Epinephelus malabaricus". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/85856602439423191075.

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碩士
國立臺灣海洋大學
食品科學系
99
This investigation elucidates the interaction of dietary vitamin C (L-ascorbyl-2-monophosphate-Na, C2MP-Na) with inorganic Manganese (Mn, MnSO4) and organic Mn (Mn-peptide) on the growth and immune responses of grouper, Epinephelus malabaricus. The amount vitamin C and Mn added to the basal diet in representing the adequate dietary level for grouper were derived from previous results. Basal diet containing either low (1/2 adequate) or adequate organic and inorganic Mn were each supplemented with adequate, 2X and 4X adequate level of C2MP-Na. There were total of 12 experimental diets, each was fed to triplicate groups of fish (initial body weight: 9.78 ± 0.17 g) for 8 weeks. After that, fish were challenged with Vibrio carchariae. Regardless of Mn source and Mn and vitamin C supplementation levels, weight gain, whole body and hepatic Mn concentration, leukocyte superoxide anion production ratio, hepatic total superoxide dismutase (SOD) and MnSOD activities, muscle and hepatic thiobarbituric acid-reactive substance (TBARS) value in fish were not different (p>0.05) among all dietary treatments. Regardless of the dietary supplementation levels of Mn and vitamin C, fish fed diets with inorganic Mn had higher bone Mn concentration than fish fed diets with organic Mn. Regardless of either organic or inorganic Mn in diet, fish fed diet supplemented with 2X and 4X adequate vitamin C had higher hepatic and body kidney vitamin C concentration than fish fed diet supplemented with adequate level of vitamin C. These results suggest that both organic Mn and inorganic Mn are equally utilized by grouper. Increase dietary vitamin C supplementation level does not enhance Mn utilization by fish, but diet with adequate vitamin C level do enhance immune responses of the fish regardless of either the source or supplementation level of Mn.

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19

Hsu, Chia-Hsiang y 許家祥. "Effects of dietary organic and inorganic copper source interact with vitamin C on the growth and immune response of grouper, Epinephelus malabaricus". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/09025503058836434589.

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碩士
國立臺灣海洋大學
食品科學系
99
This investigation elucidates the interaction of dietary vitamin C (L-ascorbyl-2-monophosphate-Na, C2MP-Na) with inorganic copper (Cu, CuSO4) and organic Cu (Cu-peptide) on the growth and immune responses of grouper, Epinephelus malabaricus. The amount vitamin C and Cu added to the basal diet in representing the adequate dietary level for grouper were derived from previous results. Basal diet containing either adequate or 2X adequate organic and inorganic Cu were each supplemented with adequate, 2X and 4X adequate level of C2MP-Na. There were total of 12 experimental diets, each was fed to triplicate groups of fish (initial body weight: 5.63±0.10g) for 8 weeks. After that, fish were challenged with Vibrio alginolyticus. Diet with adequate vitamin C level regardless of the Cu supplementation level, fish fed diets with organic Cu had higher (P<0.05) weight gain than fish fed diets with inorganic Cu. Regardless of Cu source and vitamin C supplementation level, fish fed diet supplemented with 2X adequate Cu had higher whole body Cu concentration than fish fed diet supplemented with adequade Cu. Regardless of Cu source and Cu supplementation level, fish fed diet supplemented with adequate vitamin C had higher whole body Cu concentration than fish fed diet supplemented with 2X and 4X adequade Cu. Regardless of Cu source and Cu supplementation level, fish fed diet supplemented with 2X and 4X adequate vitamin C had higher macrophage superoxide anion production ratio than fish fed diet supplementated with adequate vitamin C. These results suggest that diet with adequate vitamin C level, fish fed diets with organic Cu had higher growth than fish fed diets with inorganic Cu. Regardless of the source and supplementation level of Cu, increase dietary vitamin C supplementation level reduce Cu accumulation and enhance the superoxide anion production ratio in fish.

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20

Asfaw, Belay Tedla. "Direct and residual effects of organic and inorganic fertilizers on soil chemical properties, microbial components and maize yield under long-term crop rotation". Thesis, 2001. http://hdl.handle.net/2263/23104.

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Management-induced degradation of soil chemical and microbial quality is one of the most pressing concerns and a considerable threat to the sustainability of agroecosystems. However, information on this important issue is limited and largely based on short-term studies. A long-term experiment initiated in 1939 at the University of Pretoria provided a unique opportunity to assess the direct and residual effects of manure and inorganic fertilizers on soil chemical properties, microbial components and maize yield in rotation with field pea. Long-term addition of manure resulted in increased total organic C (TOC), total N and available P levels in the soil. Seasonally, these nutrients exhibited variations that appeared to be related to influences of crop rotation. Soil N content in an adjacent native site remained relatively constant but tended to increase in the control and manured plots. Soil microbial biomass C, N and P and microbial populations were affected by previous manure application as well as by crop rotation. Microbial biomass and numbers were generally higher in the manured plots. Manure application also had substantial residual effects and resulted in maize grain yields higher than in the control. Long-term NPK application resulted in decreased TOC and basic cation contents, and lowering of soil pH. The decrease in TOC was greater in single fertilizer treatments whereas basic cation contents and pH declined more in the balanced fertilizer treatments. Soil microbial biomass and numbers were influenced by, and exhibited qualitative changes in response to, long-term fertilization. Crop rotation also exerted effects on chemical and microbial properties of the soil. Maize grain yield showed significant increases in response to balanced fertilizer treatments. Response of maize to simple fertilizer applications was not beneficial in terms of yield returns. These results suggest that judicious use of inorganic fertilizers may, in the long-term, maintain soil quality and productive capacity. A comparison of the effects of residual manure and NPK fertilizers on the content of selected nutrients, microbial properties, C and N inputs, tissue nutrient concentration and crop yield showed differences due to treatments. TOC, total N and available P levels were increased due to residual manure alone or in combination with NPK fertilizers. C and N inputs and tissue P concentration were also generally higher in manured than in the NPK treatment. However, the higher increase in nutrient contents of manured plots was not reflected in microbial properties of the soil. Despite lower nutrient levels, the NPK treatment resulted in relatively greater increases in microbial properties of the soil. The differential responses were largely due to differences in quality and decomposability of organic material. Organic material in the NPK treatment appeared to have a higher decomposition and turnover rate than in other treatments, suggesting that C limitation in soils of low C but good nutrient supply may be compensated by high turnover rates of the available organic materials. The beneficial effect of residual manure on microbial properties and crop yield was decreased by application of supplemental N fertilizer but remained unaffected by application of supplemental K fertilizer. The depressive effect of excess soil P levels on soil microbial properties and crop yield was exacerbated by supplemental N fertilizer and mitigated by supplemental manure and K fertilizer applied to residual P. The decrease in available P levels due to supplemental K application implies that this may serve as a viable alternative to ameliorate soils with excess P levels.
Thesis (PhD (Plant Production and Soil Science))--University of Pretoria, 2003.
Plant Production and Soil Science
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21

Chakraborty, Shubhadip. "Gas Phase Infrared Spectroscopy of Large Aromatic Molecules : Fermi Resonance in the C-H Stretching Region". Thesis, 2015. http://etd.iisc.ernet.in/2005/3859.

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In this thesis, I have investigated gas phase infrared spectroscopy of environmentally as well as astrophysical important large organic molecules such as naphthalene, methy-lated naphthalene, fluorine, methyalted fluorine etc. which are commonly known as polycyclic aromatic hydrocarbons (PAHs). Depending upon the molecular weight these organic molecules can exist both in gaseous as well as in the particulate state at room temperature hence they are the major environmental pollutants. They are also responsible for the unidentified infrared emission bands in the interstellar medium. Chapter 1 provides a brief introduction to my thesis work. A detailed literature survey on the importance, abundance of the PAHs in the environment as well as various spectroscopic techniques useful for identifying the PAHs has been done. Since the objective of my thesis work is to assign the observed fundamental infrared bands of large organic molecules with the help of high level quantum mechanical calculations, a brief introduction to the various high level quantum mechanical techniques that I have used in assigning the bands have been described in this chapter. In Chapter 2 I have presented the experimental and the theoretical methodologies in details. The chapter begins with a detailed description of the experimental procedure used for recording the infrared spectrum of these molecules followed by the theoretical methodologies used for the assignment of the observed infrared bands as well as for identifying the Fermi resonances. In Chapters 3 and 4, of this thesis I have recorded infrared spectrum of 1-and 2-methylnaphthalene (1-and 2-MN), fluorine (FL), 1-methylfluorene (1-MFL) and 1,8-dimethylfluorene (1,8-DMF) in the gas phase. The observed bands were assigned with the help of scaled harmonic frequency, scaled quantum mechanical harmonic force field (SQMFF) and enharmonic frequency calculations. The first two methods are based on the harmonic approximation, whereas the enharmonic frequency calculation is based on the standard second order perturbation theory. All these calculations gave me a partial fit to the fundamental bands in both aromatic and aliphatic C-H stretching as well as in the non C-H stretching region. At the end of both the chapters an error analysis in fitting the spectrum from all the three different calculations have been presented. Evidently the non linear least square fitting method employed in SQMFF calculation gives much better agreement between the experiment and theory than the other two methods. It has been observed in the experimental spectrum of methylated naphthalene that the band structure near the C-H stretch around 3000 cm−1 is very complicated and many bands and shoulders remain unassigned by the methods described in Chapters 3 and 4. Fermi resonance is one of the potential reason for the complicated band structure in this region. In Chapter 5, I have taken naphthalene and have investigated the Fermi resonance around the C-H stretching region using an effective vibrational hamiltonian (EVH) approach. In this method I have constructed an EVH consisting of 8 C-H stretches and 8 H-C-C in-plane bend overtones and 28 H-C-C in-plane bend combination modes as the basis. Both type 1 (stretch overtone) and type 2 (stretch combination) Fermi resonances were investigated. Calculated frequencies belonging to B1u and B2u irreducible representation were compared with the observed bands. Many bands and shoulders have been assigned as the overtone and combination modes of low frequency H-C-C bend motion obtained from the EVH approach. How-ever some bands remain unassigned in this method. This is perhaps due to the neglect of the carbon framework motion in the construction of the EVH. To improve upon the results obtained from the EVH formalism I included the carbon frame degrees of freedom and have carried out a full variation treatment in curvilinear coordinates. I have considered the 8 C-H stretches and 8 H-C-C in-plane bends of naphthalene as local mode oscillators and 17 coordinates belonging to the carbon framework motion as curvilinear normal mode oscillators. A quartic hamiltonian in a mixed local mode -normal mode basis was constructed including up to three body terms in both kinetic and potential energy part. The hamiltonian was subsequently recast into the ladder operator form and diagonal zed in a symmetry adapted basis with polyad constraints. Frequencies so obtained were compared to the experiment All these findings have been presented in Chapter 6 of this thesis. The concluding remark of the thesis and the future direction is presented in Chapter 7

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22

Yadav, Ruchika. "Growth and Studies of Phase Transitions in Multifunctional Perovskite Materials". Thesis, 2015. http://etd.iisc.ernet.in/2005/3680.

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Crystal growth and characterization of few multifunctional materials with perovskite (ABX3) structure are discussed in this thesis. Efforts were made to modify the magnetic and electric behaviour of these materials by selective tuning of A, B and X components. Structural, magnetic and dielectric characterization are detailed in various chapters for doped (A and B site) rare-earth manganites and organometallic compounds with different (Chloride or formate) anions. The relevant aspects of crystal structure and its relationship with ordered ground states are discussed in the introductory chapter. A detailed review of prominent theories pertaining to magnetic and ferroelectric ordering in the literature is provided. Growth of various inorganic compounds by solid-state reaction and floating zone method as well as use of solvothermal techniques for growing organometallic compounds are discussed. Material preparation, optimization of crystal growth processes and results of characterization are addressed in various chapters. The effect of Yttrium doping on structural, magnetic and dielectric properties of rare-earth manganites (RMnO3 where R = Nd, Pr) has been investigated. Neutron diffraction studies (Pr compounds) confirm A-type antiferromagnetic structure and fall in transition temperature as the Yttrium doping level increases. Diffraction experiments in conjunction with dc magnetization and ac susceptibility studies reveal magnetic frustration in excess Yttrium dopedcompounds. When mutliglass properties of 50% B-site doped Nd2NiMnO6 were investigated, evidence of re-entrant cluster glass phase was seen probably due to presence of anti-site disorder. The relaxor-like dielectric behaviour arises from crossover of relaxation time in grain and grain boundary regions. Multiferroic behaviour of the organometallic compound (C2H5NH3)2CuCl4 as well as the ferroelectric transition were investigated in detail. The role of Hydrogen bond ordering in driving structural transitions is elucidated by low temperature dielectric and Raman studies in (C2H5NH3)2CdCl4. It was found possible to tune the magnetic and ferroelectric properties in metal formate compounds (general formula AB(HCOO)3) by selectively choosing organic cations [(CH3)2NH2+; C(NH3)3+] and transition metal ion [B = Mn, Co and Cu]. The nature of magnetic ordering and transition temperature could be altered by the transition metal ion. The effect of reorientation of organic cations which leads to ferroelectric nature is discussed using dielectric and pyroelectric data. Significant results are summarized in the chapter outlining general conclusions. Future prospects of work based on these observations are also provided. The conclusions are corroborated by detailed analysis of experimental data.

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23

Tedla, Asfaw Belay. "Direct and residual effects of organic and inoganic fertilizers on soil chemical properties, microbial components and maize yield under long-term crop rotation". Thesis, 2001. http://hdl.handle.net/2263/26074.

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Management-induced degradation of soil chemical and microbial quality is one of the most pressing concerns and a considerable threat to the sustainability of agroecosystems. However, information on this important issue is limited and largely based on short-term studies. A long-term experiment initiated in 1939 at the University of Pretoria provided a unique opportunity to assess the direct and residual effects of manure and inorganic fertilizers on soil chemical properties, microbial components and maize yield in rotation with field pea. Long-term addition of manure resulted in increased total organic C (TO C), total Nand available P levels in the soil. Seasonally, these nutrients exhibited variations that appeared to be related to influences of crop rotation. Soil N content in an adjacent native site remained relatively constant but tended to increase in the control and manured plots. Soil microbial biomass C, Nand P and microbial populations were affected by previous manure application as well as by crop rotation. Microbial biomass and numbers were generally higher in the manured plots. Manure application also had substantial residual effects and resulted in maize grain yields higher than in the control. Long-term NPK application resulted in decreased TOC and basic cation contents, and lowering of soil pH. The decrease in TOC was greater in single fertilizer treatments whereas basic cation contents and pH declined more in the balanced fertilizer treatments. Soil microbial biomass and numbers were influenced by, and exhibited qualitative changes in response to, long-term fertilization. Crop rotation also exerted effects on chemical and microbial properties of the soil. Maize grain yield showed significant increases in response to balanced fertilizer treatments. Response of maize to simple fertilizer applications was not beneficial in terms of yield returns. These results suggest that judicious use of inorganic fertilizers may, in the long-term, maintain soil quality and productive capacity. A comparison of the effects of residual manure and NPK fertilizers on the content of selected nutrients, microbial properties, C and N inputs, tissue nutrient concentration and crop yield showed differences due to treatments. TOC, total N and available P levels were increased due to residual manure alone or in combination with NPK fertilizers. C and N inputs and tissue P concentration were also generally higher in manured than in the NPK treatment. However, the higher increase in nutrient contents of manured plots was not reflected in microbial properties of the soil. Despite lower nutrient levels, the NPK treatment resulted in relatively greater increases in microbial properties of the soil. The differential responses were largely due to differences in quality and decomposability of organic material. Organic material in the NPK treatment appeared to have a higher decomposition and turnover rate than in other treatments, suggesting that C limitation in soils of low C but good nutrient supply may be compensated by high turnover rates of the available organic materials. The beneficial effect of residual manure on microbial properties and crop yield was decreased by application of supplemental N fertilizer but remained unaffected by application of supplemental K fertilizer. The depressive effect of excess soil P levels on soil microbial properties and crop yield was exacerbated by supplemental N fertilizer and mitigated by supplemental manure and K fertilizer applied to residual P. The decrease in available P levels due to supplemental K application implies that this may serve as a viable alternative to ameliorate soils with excess P levels.
Thesis (PhD)--University of Pretoria, 2010.
Plant Production and Soil Science
unrestricted

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Tesis sobre el tema "Organic-inorganic c"

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