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1
Labonnette, Daniel. "Etude des especes du vanadium iv en milieu faiblement acide et alcalin : isopolyanions mixtes mo**(vi)-v**(iv), complexes carbonates de v**(iv)." Orléans, 1987. http://www.theses.fr/1987ORLE2009.
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L'alcalinisation progressive d'une solution acide de vo**(2+) par une base forte, entraine la formation successive des especes : vooh**(+), (vooh)::(2)**(2+) vo(oh)::(2), v::(4)o::(9)h**(-), v::(4)o::(9)h**(-), v::(4)o::(9)**(2-), vo(oh)::(3)**(-) et des ions polycondenses en milieu fortement basique et tres concentre en v(iv). Quand l'alcalinisation est realisee par hco::(3)**(-) ou co::(3)**(2-), il y a formation de complexes carbonato
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Kuwata, Shigemasa. "Transition metal complexes of 3,7-diazabicyclo[3.3.1]nonane derivatives complex stabilities and oxidation reactivity of cobalt (II) and vanadium (IV) /." [S.l. : s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=974319856.
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Walmsley, Ryan Steven. "An investigation into the antidiabetic and catalytic properties of oxovanadium(IV) complexes." Thesis, Rhodes University, 2012. http://hdl.handle.net/10962/d1004978.
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In part 1 of this thesis, the antidiabetic activity of a series of novel oxovanadium(IV) complexes was investigated. A range of bidentate N,O-donor ligands, which partially mimic naturally occurring bioligands, were prepared and reacted with the vanadyl ion to form the corresponding bis-coordinated complexes. Initially, 2-(2ˊ-hydroxyphenyl)-1R-imidazoline (where R = H, ethyl and ethanol) ligands were prepared. The aqueous pH-metric chemical speciation was investigated using glass electrode potentiometry which allowed for the determination of protonation and stability constants of the ligands and complexes, respectively. The species distribution diagrams generated from this information gave an indication of how the complexes might behave across the broad pH range experienced in the digestive and circulatory systems. This information was used to create an improved 2nd generation of ligands that were constructed by combining the imidazole and carboxylic acid functionalities. These corresponding bis[(imidazolyl)carboxylato]-oxovanadium(IV) complexes displayed a broader pH-metric stability. Both sets of complexes improved glucose uptake and reduced coagulation in vitro. In part 2 of this thesis, a range of homogeneous and heterogeneous oxovanadium(IV) catalysts were prepared. Firstly, Merrifield beads were functionalized with ligands from Part 1 and then reacted with vanadyl sulfate to afford the corresponding heterogeneous catalysts. These displayed promising catalytic activity for the peroxide facilitated oxidation of thioanisole, styrene and ethylbenzene as well as the oxidative bromination of phenol red. Smaller imidazole-containing beads with higher surface areas than the Merrifield beads were prepared by suspension polymerization. These beads similarly demonstrated excellent catalytic activity for the oxidation of thioanisole and were highly recyclable. In attempt to increase the exposed catalytic surface area, while retaining the ease of separation achieved in the before mentioned systems, micron to nano sized electrospun fibers containing coordinating ligands were fabricated. The corresponding oxovanadium(IV) functionalized fibers were applied to the oxidation of thioanisole using a continuous flow system. The flexible and porous nature of the fiber mats was well suited to this approach. After optimization of the reactant flow rate and catalyst amount, near quantitative (> 99%) oxidation was achieved for an extended period. In addition, leaching of vanadium was mitigated by modification of the attached ligand or polymer material.
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Ugirinema, Vital. "Biospeciation and antidiabetic effects of oxidovanadium(IV) complexes." Thesis, Nelson Mandela Metropolitan University, 2014. http://hdl.handle.net/10948/d1020973.
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The syntheses of bis(1R-imidazole-2/4-carboxylato)oxidovanadium(IV) complexes was successfully carried out and the complexes were isolated in the solid state. The coordinated water was confirmed by elemental analyses, and single crystal XRD. The complexes were therefore distorted octahedral rather than square planar due to the coordination of water at the sixth position. The reaction of the vanadyl ion (VO2+) with imidazole-4-carboxylic acid (Im4COOH), imidazole-2-carboxylic acid (Im2COOH) and methylimidazole-2-carboxylic acid (MeIm2COOH), respectively, in the presence of small bioligands (bL) [oxalate (Ox), lactate (Lact), and phosphate (Phos)] and high molecular weight (HMM) human serum proteins [albumin (HSA) and transferrin (hTf)] were studied in aqueous solution using potentiometric acid base titrations under oxygen and carbon dioxide–free conditions. The data obtained from these titrations was used to calculate the binary and ternary stability constants using the programme HYPERQUAD. The overall stability constants for VO2+-L-Ox system (log β1111 = 18.9, 18.79 and 19.86), VO2+-L-Lact system (log β1111 = 21.83, 20.98 and 22.86), and VO2+-L-Phos system (log β1111 = 27.35, 24.16 and 27.42) (for L= Im4COOH, Im2COOH and MeIm2COOH, respectively) were obtained. The species distribution diagrams showed that under physiological pH the following ternary and quaternary species; [(VO)L(bL)], and [VO(L)(bL)(OH)], would dominate provided that the competition with serum proteins is not too strong. These species were also confirmed by HPLC, LC-MS and EPR. The overall stability constants for the VO2+-L-HSA system (log β2,1,1,0 = 24.3, 23.7 and 24.7), and for the VO2+-L-hTf system (log β2,2,1,0 = 31.1, 30.8, 36.4 for L = Im4COOH, Im2COOH and MeIm2COOH, respectively), suggesting stronger binding of transferrin. The formation constants for the formation of binary (VO(IV) and the proteins) were 9.1 and 13 for log β11, and 20.9 and 25.2 for β12, for human serum albumin and human serum transferrin respectively. The species distribution diagrams for the proteins (HMM) with oxidovanadium(IV) under physiological pH was dominated by VO(HMM)2, VOL(HMM) for unsubstituted Im4COOH and Im2COOH, however, for the N-substituted MeIm2COOH, the species distribution diagrams under physiological pH, were dominated by VOL2, VO(HMM)2 and VO2L2(HMM). These species were further confirmed by HPLC, MALDI-TOF-MS and EPR. The glucose stimulated insulin secretion (GSIS) action of the complexes was investigated using INS-1E cells at 1μM concentration which was established through cytotoxicity studies via the MTT assay. The vanadium salt (VOSO4), cationic vanadium(IV) complex ([VO(MeImCH2OH)2]2+) were also included in the GSIS study in addition to the three neutral complexes [VO(Im4COO)2, VO(Im2COO)2 and VO(MeIm2COO)2] for comparison. The neutral complexes, especially VO(MeIm2COO)2, showed promising results in the stimulation of insulin secretion than the cationic complex and the vanadium salt.
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Alvino, De la Sota Nora, and Calderón Javier Pacheco. "Diseño de Agentes Antidiabéticos de Vanadio: Desarrollo y Avances Recientes." Revista de Química, 2007. http://repositorio.pucp.edu.pe/index/handle/123456789/100688.
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El descubrimient o del mayor efecto hipoglicémic o del bis(maltolato)oxovanadio (IV) (BMOV) con respecto a las salesde vanadio, propició el diseño, síntesis y evaluación in vitro e in vivo de una amplia variedad de complejos de oxovanadio(IV) con diversos ligandos orgánicos para su potencial uso como fármacos antidiabéticos que reemplacen , parcial ototalmente , las incómodas inyecciones de insulina en el tratamiento de la diabetes mellitus tipo 1 o los fármacos oraleshipoglicemiante s empleados generalment e en terapias combinadas para la tipo 2.Recientemente , un complejo etil sustituido , análogo al BMOV, ha completado favorablemente la fase clínica I deensayos en humanos. El diseño de nuevos tipos de complejos y el desarrollo de nuevos modos de administración constituyenactualmente un activo campo de investigación<br>Design of Vanadium Antidiabetic Agents: Development and Recent AdvancesThe discovery of the enhanced hypoglycemic activity of bis(maltolate)oxovanadiu m (IV) (BMOV) compared to simplevanadium salts stimulated the design, synthesis and both in vitro and in vivo evaluation of a large variety of oxovanadium (IV)complexes with different organic ligands for their potential use as antidiabetic drugs that may be able to substitute, either partially or totally, the daily insulin injections used in the treatment of type 1 diabetes mellitus or the orally available hypoglycemic drugs usually used in combined therapy for type 2 diabetes.Recently, a close BMOV analogue, an ethyl substitute, has already successfully completed the phase 1 clinical trial in humans. The design of new types of complexes and the development of alternative delivery methods represent an active research field today.
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Weiss, Vitor Correa. "Complexos de vanádio(IV) não oxo." reponame:Repositório Institucional da UFSC, 2012. http://repositorio.ufsc.br/xmlui/handle/123456789/93103.
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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas, Programa de Pós-Graduação em Química, Florianópolis, 2009.<br>Made available in DSpace on 2012-10-24T16:40:44Z (GMT). No. of bitstreams: 1
273349.pdf: 901411 bytes, checksum: b664df92fc9cf4e20e2e9976ba78a192 (MD5)<br>A existência de diferentes estados de oxidação é uma característica importante na química dos metais de transição. O potencial de oxirredução de um complexo metálico não depende somente da natureza do íon metálico. A presença de um ligante complexado ao metal altera a densidade eletrônica sobre os centros metálicos e a estabilidade dos mesmos, afetando os potenciais de oxirredução dos íons metálicos. Neste sentido, apresenta-se neste trabalho a síntese e caracterização de quatro novos ligantes H4btben-Br, H4btben-NO2, H4btben e H4btben-CH3, que diferem exclusivamente na presença dos grupos substituintes Br, NO2, H e CH3 nas posições para aos grupos fenolatos, e seus respectivos complexos de vanádio(IV) não-oxo, com o objetivo de estudar a variação no potencial redox do metal devido a presença desses substituintes. Os complexos foram caracterizados pelas técnicas de espectroscopia no infravermelho, UV-Vis e Ressonância Paramagnética Eletrônica (EPR). Os complexos [V(btben-NO2] e [V(btben)] também foram caracterizados através de suas estruturas cristalinas por difração de raios X. Para estudar a influência no potencial redox do íon metálico pelos quatro grupos substituintes Br, NO2, H e CH3, foram realizados estudos eletroquímicos dos complexos através do método de voltametria cíclica a diferentes velocidades de varredura e seus potenciais correlacionados com os parâmetros de Hammett dos respectivos substituintes, onde se observou uma correlação linear, demonstrando uma influência direta dos grupos nos potenciais redox desses complexos.
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Olivier, Isabelle. "Stabilité et structure des complexes du cuivre (II) et du vanadium (IV) avec des sucres." Lille 1, 1990. http://www.theses.fr/1990LIL10009.
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Ce travail aborde l'étude de la coordination de sucres amines, d'acides uroniques et de l'acide salicylique avec les ions CU (II) et VO (IV). Il constitue une approche des mécanismes chimiques de l'assimilation par les plantes des éléments nutritifs contenus dans les sols. La spectroscopie électronique, le dichroisme circulaire et la résonance paramagnétique électronique interviennent pour caractériser l'environnement chimique de l'ion complexe, la potentiométrie, outil principal de l'investigation, permet de déterminer la stabilité des complexes formes. Seul CU (II) se complexe avec les sucres aminés, le groupement aminé apparaissant comme premier site de complexation. Les groupements hydroxyles deprotonés en position c(1) et c(3) interviennent directement dans la formation des complexes ML2 H2 et sous forme protonés ont un rôle stabilisateur dans celle de ML2. Des différences de stabilité sont relevées avec les acides uroniques, en relation avec la nature de l'ion, cuivre(II) ou oxovanadium(IV). A ph<5, dans tous les cas on observe la formation des uronates. Au-dela de ce ph les espèces m(ac gal)2 h2 et M(AC GAL)2H1 apparaissent pour les systèmes ou intervient l'acide d-galactoronique. Par contre avec l'acide d glucuronique, l'hydroxyde en c(4) n'intervient pas dans la coordination, ce qui entraîne la formation d'espèces polymérisées. Avec l'acide salicyclique, le processus de complexation proposé met en évidence une double compétition entre ligands différents (sal et oh-) et les espèces à 1 ou 2 molécules d'acide salicylique
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Thompson, Nicholas John. "Chromium (III), Titanium (III), and Vanadium (IV) sensitization of rare earth complexes for luminescent solar concentrator applications." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/69674.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2011.<br>This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (p. 56-59).<br>High optical concentrations without excess heating in a stationary system can be achieved with a luminescent solar concentrator (LSC). Neodymium (Nd) and ytterbium (Yb) are excellent infrared LSC materials: inexpensive, abundant, efficient, and spectrally well-matched to high-performance silicon solar cells. These rare earth ions are reasonably transparent to their own radiation and capable of generating high optical concentrations. Neodymium's and ytterbium's disadvantage is their relatively poor absorption overlap with the visible spectrum. Transition metals such as chromium (Cr), titanium (Ti), and vanadium (V) have broadband absorption covering the visible and near-infrared and can efficiently sensitize neodymium and ytterbium through a non-radiative energy transfer process. Chromium, titanium, and vanadium containing glasses were fabricated using a custom designed glass making furnace. The optical properties including molar absorption coefficient, photoluminescence spectrum, and energy transfer characteristics were investigated to determine the suitability for LSC applications. Glasses containing Cr or V co-doped with Nd or Yb demonstrated energy transfer from the transition metal to the rare earth, a fundamental step toward integration into a LSC. Titanium co-doped glasses did not exhibit photoluminescence or energy transfer. Chromium co-doped glasses exhibit both forward and backward energy transfer. Vanadium holds the best promise as a sensitizer for LSC applications.<br>by Nicholas John Thompson.<br>S.M.
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Labonnette, Daniel. "Etude des espèces du vanadium IV en milieu faiblement acide et alcalin isopolyanions mixtes MoVI-VIV, complexes carbonatés de VIV /." Grenoble 2 : ANRT, 1987. http://catalogue.bnf.fr/ark:/12148/cb37606781k.
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Jäger, Norbert. "Molekülmechanische und quantenchemische Berechnung der räumlichen und elektronischen Struktur von Vanadium(IV)- und Oxo-Rhenium(V)-Chelaten dreizähnig diacider Liganden." Phd thesis, Universität Potsdam, 1998. http://opus.kobv.de/ubp/volltexte/2005/154/.
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In dieser Arbeit wurden die Molekülstrukturen und die elektronischen Eigenschaften von Vanadium(IV)- und Oxo-Rhenium(V)-Chelaten mit einem kombinierten molekülmechanisch-quantenchemischen Ansatz untersucht, um sterische und elektronische Effekte der Komplexierung mit einem theoretischen Modell zu quantifizieren. Es konnte gezeigt werden, daß auf diese Weise detaillierte Aussagen zu den Bindungsverhältnissen der Metallchelate getroffen werden können. Die Berechnung der Molekülstrukturen gelingt mit exzellenter Übereinstimmung mit den Kristallstrukturen der Komplexe. Die molekülmechanischen Berechnungen erfolgen auf der Grundlage des Extensible Systematic Force Field ESFF und des Consistent Force Field 91 (CFF91). Dabei konnte die hohe Flexibilität und Zuverlässigkeit des regelbasierten ESFF für eine Vielzahl verschiedenster Metallchelate nachgewiesen werden. Aufgrund der mangelhaften Ergebnisse für trigonal-prismatische Komplexgeometrien mit dem ESFF wurden eine Anpassung des CFF91 für derartige Vanadiumkomplexe vorgenommen. Auf Grundlage von theoretischen Ergebnissen wurden die alternativen Strukturen von isoelektronischen Vanadiumkomplexen berechnet und in Übereinstimmung mit experimentellen Daten, theoretischen Modellen der Komplexchemie und empirischen Fakten eine Hypothese für die Ursache der strukturellen Differenzen erarbeitet.<br> Der hier vorgestellte, kombinierte Algorithmus aus kraftfeldbasierter Geometrieoptimierung und single-point-Rechnung an diesen Strukturen ist ein zuverlässiger und relativ schneller Weg Molekülgeometrien von Metallkomplexen zu berechnen. Er kann somit zur Voraussagen von Komplexstrukturen und zur gezielten Modellierung definierter Koordinationsgeometrien verwendet werden.<br>In this work the molecular structures and the electronic properties of Vanadium(IV)- and Oxo-Rhenium(V)-chelates have been investigated to quantify steric and electronic effects of complexation. It has been shown, that in this way detailed insight can be gained into the bonding conditions of that metal complexes. Molecular mechanic calculations based on the Extensible Systematic Force Field (ESFF) and the Consistent Force Field 91 (CFF91) have been carried out. High flexibility and reliability of the rule based ESFF has been proven for a large variety of different metal chelates. Due to the poor ESFF-results for trigonal-prismatic complex geometries, a fit of the CFF91 for that species was done. Based on the theoretical results the alternative structure of isoelectronical vanadium(IV)- complexes have been calculated and a hypothesis on the reason for the structural differnces have been stated in accordance with experimental results, theoretical models of complex chemistry, and empirical facts. This combined approach of force field based geometry optimization and single point calculation at these structures has been proven to be a reliable and fast way to get molecular structures of metal complexes. It can be used to predict complex structures for modelling destinct coordination geometries.
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Wheeler, Dale E. "The chemistry of para-tolylimidovanadium V trichloride: synthesis and characterization of dialkyldithiocarbamate and related derivatives and of bis(organophosphine)vanadium IV complexes." 1986. http://hdl.handle.net/2097/22175.
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Kuwata, Shigemasa [Verfasser]. "Transition metal complexes of 3,7-diazabicyclo[3.3.1]nonane derivatives : complex stabilities and oxidation reactivity of cobalt (II) and vanadium (IV) / vorgelegt von Shigemasa Kuwata." 2005. http://d-nb.info/974319856/34.
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Wen, Shung-Shien, та 溫學賢. "(一) vanadium(IV) complex mediated in catalyze asymmetric Mukaiyama aldol addition reaction (二)Study of C2 symmetric 2,6-dioxabicycle[3,3,0]octane as chiral templet". Thesis, 1999. http://ndltd.ncl.edu.tw/handle/04931318409431181780.
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碩士<br>國立臺灣師範大學<br>化學研究所<br>87<br>Condensation of vanadyl sulfate with 2,2-biphenol in the presence of N-containing ligands provides oxovanadium complexes which serve as efficient catalysts in Mukaiyama aldol reactions to afford aldol products in 78-99% yields with diastereoselectivities of up to 91/9 (anti/syn)
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Kumar, Arun. "Vanadium Complexes for DNA Crosslinking and Photodynamic Applications." Thesis, 2018. http://etd.iisc.ac.in/handle/2005/4328.
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The present thesis work deals with the studies involving synthesis of vanadium-based complexes as photoactivated chemotherapeutic as well a photodynamic therapeutic agent. Their interactions with DNA, as double-stranded DNA crosslinkers, visible light induced cytotoxic effect on cancerous cells, mechanistic aspects of cell death, and cellular localization behavior were studied.
Chapter I presents a brief introduction to the metal-based photochemotherapeutic and DNA crosslinking agents. Importance of vanadium metal in medicinal as well as biological aspects is discussed. The significance of photoactivated chemotherapy (PACT) and photodynamic therapy (PDT) in cancer treatment is discussed. A discussion on the opportunities and motivation for the development of metal-based anticancer agents is also made. DNA crosslinks and its relation to cancer and cancer treatment are presented. Objective of the present investigation is also dealt in this chapter.
Chapter II of the thesis deals with the synthesis, characterization and DNA damaging ability of a dioxovanadium(V) complex of vitamin-B6 Schiff base. The complex exhibited significant reactive oxygen species (ROS) mediated apoptotic photocytotoxicity in the cancer cells, while being essentially non-toxic in the dark. Alkaline Comet assay showed damage of nuclear DNA.
Chapter III presents synthesis and characterization of two oxovanadium(IV) complexes, viz. [VO(pyphen)Cl2] (2) and [VO(pydppz)Cl2] (3), where pyphen is 2-(2'-pyridyl)-1,10-phenanthroline and pydppz is 3-(pyridin-2-yl)dipyrido[3,2-a:2',3'-c]phenazine. The complexes exhibited photo-induced DNA crosslinking property and photo-cytotoxicity.
Chapter-IV deals with oxovanadium (IV) complexes, viz. [VO(L1/L2)Cl2]n+ (4, 5) of anthracenyl terpyridine and triphenyl phosphonium-appended anthracenyl terpyridine. Upon photo-irradiation with visible light (400-700 nm), The complexes showed significant photocytotoxicity in visible light with low dark toxicity in HeLa and MCF-7 cells. FACScan analysis showed cellular apoptosis when treated with the complex in visible light in comparison to their dark controls. The photocytotoxicity of the complexes was attributed to their DNA crosslinking ability. Fluorescence microscopic studies revealed mitochondrial localization of the complex within the cancer cells.
Chapter V deals with the synthesis, characterization, photo-induced DNA crosslinking ability and photocytotoxicity of the oxovanadium (IV) complexes, viz. [VO (dpa/L1/L2)Cl2] (7-9) of glucose or biotin appended ligands. Cell death mechanism was found out to be apoptic in nature. The complexes displayed enhanced cellular uptake in cancerous cells. The cytotoxicity of the complexes is comparable with the already available DNA crosslinking drug cis-platin.
In Chapter VI we have designed the oxovanadium (IV) complexes of BODIPY appended dipicolyl amine. The complexes, viz. [VO (bzdpa/L1/L2)Cl2] (10-12) were synthesized, characterized and their cellular uptake, photocytotoxicity, DNA crosslinking ability and mode of photo-induced cell death in cancer cells was studied. Mitochondria targeting photocytotoxic property of the complexes has been studied in details.
Finally, the summary of the dissertation and conclusions drawn from the present investigations are presented.
The references in the text have been indicated as superscript numbers and assembled at the end of each chapter. The complexes presented in this thesis are represented by bold-faced numbers. Due acknowledgements have been made wherever the work described is based on the findings of other investigators. Any omission that might have happened due to oversight or mistake is regretted.
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Wang, Rong-Ching, and 王榮慶. "Synthesis and characterization of Vanadium(III、IV)complexes of Tri(thiolate)phosphine ligands." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/00020082741931467124.
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碩士<br>國立成功大學<br>化學系碩博士班<br>94<br>Vanadium plays important roles in biology and medicine. For instance, vanadium containing nitrogenase (V-nitrogenase) catalyzes the reduction of dinitrogen to ammonia. Some vanadium compounds such as VIVO-bis(maltolato), VIVO-bis(acetylacetonato) and VV-dipicolinato were found to replace insulin for treating type II diabetes.
The mechanism of vanadium nitrogenase catalyzes nitrogen fixation is still obscure. How vanadium compounds can treat diabetes is also not well understood. According to the spectroscopic studies, vanadium site in V-nitrogenase has a S-rich coordination environment. It has been reported that the mechanism of vanadium insulin mimics might be related to the interaction of vanadium compound with the cystein residue of protein tyrosine phosphatase (PTP). Thus, it is very important to have a fully understanding for the chemistry of vanadium compounds, particularly, in sulfur-rich ligation environment. In this research, we use polythiolate ligands, and [PS3]H3 (P(C6H4-2-SH)3), [PS3’]H3 (P(C6H3-5-Me-2-SH)3), and[PS3”]H3 (P(C6H3-3-SiMe3-2-SH)3) as a title ligand for reacting with VIII species. We obtained [(C3H7)4N][VIII(PS3)N3] (1), [PPh4][VIV(PS3”)(PS3”SH)] (2) and [VIV(PS3”)(PS3”S-C-S)] (3). Compound 1 is the first example of V(III) species binding to an N3- ion, an alternate substrate of nitrogenase. In addition, the catalytic reactivity of the reduction of azide by [VIII(PS3”)Cl]- was also investigated. [PPh4][VIV(PS3”)(PS3”SH)] (2) and [VIV(PS3”)(PS3”S-C-S)] (3) represent rare examples of seven-coordinate nonoxovanadium(IV) compounds. In this dissertation, we will detail the syntheses, structural characterization, reactivities, spectroscopies of these compounds.
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Yeh, Chao-Hsuan, and 葉釗瑄. "Synthesis and Characterization of Vanadium(IV) NNO-Schiff Base Complexes: Their Application in DNA Photocleavage and Photocytotoxicity." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/52c4yu.
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碩士<br>國立中興大學<br>化學系所<br>101<br>A series of vanadium(IV) complexes [V(Ln)B](ClO4)] (1d-4e) (n=1 – 4, B= dppz, d; dppn, e) have been synthesized and characterized by elemental analysis, ESI-MS, Cyclic Voltammetry and UV-Vis spectroscopy.
Their activity and mechanism for photo-induced cleavage of supercoiled DNA are investigated under UVA light (365 nm) and blue light (430 nm) condition. Furthermore, Photocytotoxicity assay against Ca9-22 and SCC-15 cancer cells indicate that dppn vanadium(IV) complexes (1e-4e) show significant photo-induced cytotoxicity under blue light. These results give impetus to new therapeutic strategies for developing photodynamic drugs.
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Zegke, Markus, H. L. M. Spencer, and Rianne M. Lord. "Fast, facile and solvent‐free dry melt synthesis of oxovanadium(IV) complexes: Simple design with high potency towards cancerous cells." 2019. http://hdl.handle.net/10454/17232.
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Yes<br>A range of oxobis(phenyl‐1,3‐butanedione) vanadium(IV) complexes have been successfully synthesized from cheap starting materials and a simple and solvent‐free one‐pot dry‐melt reaction. This direct, straightforward, fast and alternative approach to inorganic synthesis has the potential for a wide range of applications. Analytical studies confirm their successful synthesis, purity and solid‐state coordination, and we report the complexes’ uses as potential drug candidates for the treatment of cancer. After a 24‐hour incubation of A549 lung carcinoma cells with the compounds, they reveal cytotoxicity values 11‐fold greater than cisplatin, and remain non‐toxic towards normal cell types. Additionally, the complexes are stable over a range of physiological pH values and show the potential for interactions with BSA.<br>University of Bradford. Grant Number: Internal Research Development Fund
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Bartlett, Malcolm Alan. "Synthesis and characterisation of novel oxovanadium(IV) Schiff base complexes: A study of their electronic spectral properties, peroxide binding affinities, DFT-calculated geometries and spectra, and cytotoxicity towards human carcinoma cells." Thesis, 2012. http://hdl.handle.net/10413/8894.
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A series of five, tetradentate Schiff-base ligands were synthesised and chelated to vanadyl to form
oxovanadium(IV) complexes. The ligands, 4,4’-{benzene-1,2-diylbis[nitrilo(1E)phen-1-yl-1ylidene]}-
dibenzene-1,3-diol (H2L1), 4,4’-{ethane-1,2-diylbis[nitrilo(1E)phenyl-1-yl-1-ylidene]}dibenzene-1,3-diol
(H2L2), 4,4’-{propane-1,2-diylbis[nitrilo(1E)phen-1-yl-1-ylidene]}dibenzene-1,3-diol (H2L3), 4,4’-{(2-
hydroxypropane-1,3-diyl)bis[nitrilo(1E)phen-1-yl-1-ylidene]}dibenzene-1,3-diol (H2L4) and 4,4’-{2,2-
dimethylpropane-1,3-diyl)bis-[nitrilo(1E)phen-1-yl-1-ylidene]}-dibenzene-1,3-diol (H2L5), characterised by
TOF-MS, IR, electronic absorption, 1H and 13C NMR spectroscopy. The ligand H2L5 was also characterised
by XRD. The ligands were shown to have a bis-zwitterionic structure in the solid state, and possibly also in
solution. Complexes were characterised by Elemental Analysis, TOF-MS, IR, electronic absorption spectra,
EPR and 51V NMR spectroscopy. They form mononuclear complexes, with one ligand binding a single
vanadyl ion.
EPR spectroscopy was performed on both the powdered form and solutions of the complexes. All the
complexes displayed axial symmetry, with increasing distortion from an ideal square pyramidal geometry
as the size and bulk of the central chelate ring was increased. Isotropic g0 values suggest solvent
interaction with the vanadium ion for the coordinating solvent DMSO. Additional distortion on the
coordination geometry, presumably from the benzyl groups of the compounds, causes the isotropic
hyperfine coupling constants to be greater than expected.
Furthermore, the ability of the complexes to bind peroxide species was investigated by following the
addition of H2O2 to the complexes using 51V NMR spectroscopy to observe shielding changes at the
vanadium nucleus, and 1H NMR spectroscopy to monitor the bulk magnetic susceptibility, via a modified
Evan’s NMR method. Similar experiments were done with sodium hydroxide for comparison. As expected,
the oxoperoxovanadium(V) complexes were more stable than their progenitor oxovanadium(IV)
complexes. Additionally, increasing the distortion from the ideal pseudo square-pyramidal coordination
geometry for the vanadyl ion resulted in a greater increase in the apparent stability of the peroxocomplexes.
This latter effect is further enhanced by the addition of a hydrogen-bonding group in close
proximity to the vanadium nucleus.
DFT calculations of the optimized geometries, natural bond orbitals, electronic absorption and infra-red
frequencies were performed for both the ligands and the complexes; nuclear magnetic resonance
calculations were performed for the ligands as well. The B3LYP/6-311G (d,p) and B3LYP/LANL2DZ level of
theories were used for the ligands and complexes respectively, except for electronic transitions, which
were calculated using TD-SCF methods for both ligands and complexes. Calculated and experimental
results were compared where possible, and showed reasonable agreement for all calculations performed.
The exception to this was for the NMR calculations for the ligands, which were poorly simulated.
Finally, the in vitro biological activity of the complexes was evaluated for cytotoxicity against the human
tumour cell lines: A549, U251, TK-10 and HT29, via an MTT assay. All complexes showed promising
anticancer activity, as evidenced by their low IC50 values for the cell lines A549, U251 and TK-10, which are
in general, lower than that observed for cisplatin. They did, however, express negligible activity against
the HT29 colon adenocarcinoma cell line; showing an apparent selectivity for certain cell lines. These
oxovanadium(IV) complexes, thus warrant further evaluation as chemotherapeutic agents.<br>Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.