1
|
Wang C, Xing N, Feng W, Guo S, Liu M, Xu Y, You Z. New mononuclear dioxidomolybdenum(VI) complexes with hydrazone ligands: Synthesis, crystal structures and catalytic performance. Inorganica Chim Acta 2019. [DOI: 10.1016/j.ica.2018.11.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
2
|
Kowol CR, Nagy NV, Jakusch T, Roller A, Heffeter P, Keppler BK, Enyedy ÉA. Vanadium(IV/V) complexes of Triapine and related thiosemicarbazones: Synthesis, solution equilibrium and bioactivity. J Inorg Biochem 2015; 152:62-73. [PMID: 26349014 DOI: 10.1016/j.jinorgbio.2015.08.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 07/29/2015] [Accepted: 08/24/2015] [Indexed: 01/07/2023]
Abstract
The stoichiometry and thermodynamic stability of vanadium(IV/V) complexes of Triapine and two related α(N)-heterocyclic thiosemicarbazones (TSCs) with potential antitumor activity have been determined by pH-potentiometry, EPR and (51)V NMR spectroscopy in 30% (w/w) dimethyl sulfoxide/water solvent mixtures. In all cases, mono-ligand complexes in different protonation states were identified. Dimethylation of the terminal amino group resulted in the formation of vanadium(IV/V) complexes with considerably higher stability. Three of the most stable complexes were also synthesized in solid state and comprehensively characterized. The biological evaluation of the synthesized vanadium complexes in comparison to the metal-free ligands in different human cancer cell lines revealed only minimal influence of the metal ion. Thus, in addition the coordination ability of salicylaldehyde thiosemicarbazone (STSC) to vanadium(IV/V) ions was investigated. The exchange of the pyridine nitrogen of the α(N)-heterocyclic TSCs to a phenolate oxygen in STSC significantly increased the stability of the complexes in solution. Finally, this also resulted in increased cytotoxicity activity of a vanadium(V) complex of STSC compared to the metal-free ligand.
Collapse
Affiliation(s)
- Christian R Kowol
- University of Vienna, Institute of Inorganic Chemistry, Währinger Strasse 42, A-1090 Vienna, Austria; Research Platform "Translational Cancer Therapy Research" University of Vienna, Waehringer Strasse 42, A-1090 Vienna, Austria.
| | - Nóra V Nagy
- Institute of Organic Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar Tudósok körútja 2, H-1117 Budapest, Hungary
| | - Tamás Jakusch
- Department of Inorganic and Analytical Chemistry, University of Szeged, H-6720 Szeged, Hungary
| | - Alexander Roller
- University of Vienna, Institute of Inorganic Chemistry, Währinger Strasse 42, A-1090 Vienna, Austria
| | - Petra Heffeter
- Research Platform "Translational Cancer Therapy Research" University of Vienna, Waehringer Strasse 42, A-1090 Vienna, Austria; Institute of Cancer Research and Comprehensive Cancer Center, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna, Austria
| | - Bernhard K Keppler
- University of Vienna, Institute of Inorganic Chemistry, Währinger Strasse 42, A-1090 Vienna, Austria; Research Platform "Translational Cancer Therapy Research" University of Vienna, Waehringer Strasse 42, A-1090 Vienna, Austria
| | - Éva A Enyedy
- Department of Inorganic and Analytical Chemistry, University of Szeged, H-6720 Szeged, Hungary.
| |
Collapse
|
3
|
Pyridoxal based ONS and ONO vanadium(V) complexes: Structural analysis and catalytic application in organic solvent free epoxidation. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.molcata.2015.03.016] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
4
|
Pourpoint F, Yehl J, Li M, Gupta R, Trébosc J, Lafon O, Amoureux JP, Polenova T. NMR Crystallography of an Oxovanadium(V) Complex by an Approach Combining Multinuclear Magic Angle Spinning NMR, DFT, and Spin Dynamics Simulations. Chemphyschem 2015; 16:1619-26. [DOI: 10.1002/cphc.201500033] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Indexed: 11/08/2022]
|
5
|
Maurya MR, Saini N, Avecilla F. Effect of N-based additive on the optimization of liquid phase oxidation of bicyclic, cyclic and aromatic alcohols catalyzed by dioxidomolybdenum(vi) and oxidoperoxidomolybdenum(vi) complexes. RSC Adv 2015. [DOI: 10.1039/c5ra16490g] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Catalytic potentials of [MoVIO2]2+ and [MoVIO(O2)]2+ complexes with dibasic tridentate ONO donor ligands for the oxidation of bicyclic, cyclic and aromatic alcohols in the presence of NEt3 are reported.
Collapse
Affiliation(s)
- Mannar R. Maurya
- Department of Chemistry
- Indian Institute of Technology Roorkee
- Roorkee 247 667
- India
| | - Neeraj Saini
- Department of Chemistry
- Indian Institute of Technology Roorkee
- Roorkee 247 667
- India
| | - Fernando Avecilla
- Departamento de Química Fundamental
- Universidade da Coruña
- Campus de A Zapateira
- 15071 A Coruña
- Spain
| |
Collapse
|
6
|
Maurya MR, Dhaka S, Avecilla F. Oxidation of secondary alcohols by conventional and microwave-assisted methods using molybdenum complexes of ONO donor ligands. NEW J CHEM 2015. [DOI: 10.1039/c4nj02208d] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Oxidation of secondary alcohols by conventional liquid phase and microwave-assisted methods using molybdenum complexes is reported.
Collapse
Affiliation(s)
- Mannar R. Maurya
- Department of Chemistry
- Indian Institute of Technology Roorkee
- Roorkee 247 667
- India
| | - Sarita Dhaka
- Department of Chemistry
- Indian Institute of Technology Roorkee
- Roorkee 247 667
- India
| | - Fernando Avecilla
- Departamento de Química Fundamental
- Universidade da Coruña
- 15071 A Coruña
- Spain
| |
Collapse
|
7
|
Sutradhar M, Pombeiro AJ. Coordination chemistry of non-oxido, oxido and dioxidovanadium(IV/V) complexes with azine fragment ligands. Coord Chem Rev 2014. [DOI: 10.1016/j.ccr.2014.01.007] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
8
|
Dash SP, Pasayat S, Bhakat S, Roy S, Dinda R, Tiekink ERT, Mukhopadhyay S, Bhutia SK, Hardikar MR, Joshi BN, Patil YP, Nethaji M. Highly Stable Hexacoordinated Nonoxidovanadium(IV) Complexes of Sterically Constrained Ligands: Syntheses, Structure, and Study of Antiproliferative and Insulin Mimetic Activity. Inorg Chem 2013; 52:14096-107. [DOI: 10.1021/ic401866x] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Subhashree P. Dash
- Department
of Chemistry, National Institute of Technology, Rourkela 769008, Odisha, India
| | - Sagarika Pasayat
- Department
of Chemistry, National Institute of Technology, Rourkela 769008, Odisha, India
| | - Saswati Bhakat
- Department
of Chemistry, National Institute of Technology, Rourkela 769008, Odisha, India
| | - Satabdi Roy
- Department
of Chemistry, National Institute of Technology, Rourkela 769008, Odisha, India
| | - Rupam Dinda
- Department
of Chemistry, National Institute of Technology, Rourkela 769008, Odisha, India
| | | | - Subhadip Mukhopadhyay
- Department
of Life Science, National Institute of Technology, Rourkela 769008, Odisha, India
| | - Sujit K. Bhutia
- Department
of Life Science, National Institute of Technology, Rourkela 769008, Odisha, India
| | - Manasi R. Hardikar
- Biometry
and Nutrition Group, Agharkar Research Institute, G.G. Agrakar Road, Pune 411004
| | - Bimba N. Joshi
- Biometry
and Nutrition Group, Agharkar Research Institute, G.G. Agrakar Road, Pune 411004
| | - Yogesh P. Patil
- Department
of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560012, India
| | - M. Nethaji
- Department
of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560012, India
| |
Collapse
|
9
|
Hall N, Orio M, Jorge-Robin A, Gennaro B, Marchi-Delapierre C, Duboc C. Vanadium Thiolate Complexes for Efficient and Selective Sulfoxidation Catalysis: A Mechanistic Investigation. Inorg Chem 2013; 52:13424-31. [DOI: 10.1021/ic4017504] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Nikita Hall
- Univ Grenoble Alpes 38041 Grenoble Cedex 9, France
- CNRS, UMR-5250 Département
de Chimie Moléculaire, Laboratoire de Chimie Inorganique Redox, Institut de Chimie Moléculaire de Grenoble, FR-CNRS-2607, BP-53, 38041 Grenoble Cedex 9, France
- TGE Réseau National de RPE interdisciplinaire, FR-3443, 75231 Paris Cedex 05, France
| | - Maylis Orio
- TGE Réseau National de RPE interdisciplinaire, FR-3443, 75231 Paris Cedex 05, France
- Univ Lille Nord de France, UDSL, CNRS UMR
8516, BP 83, 59000 Lille, France
- Laboratoire de Spectrochimie
Infrarouge et Raman, CNRS LASIR-UMR 8516, Bat C4 59655 Villeneuve d’Ascq Cedex, France
| | - Adeline Jorge-Robin
- Univ Grenoble Alpes 38041 Grenoble Cedex 9, France
- CEA, iRTSV, LCBM, 38054 Grenoble, France
- CNRS, UMR 5249, Grenoble, France
| | - Béatrice Gennaro
- Univ Grenoble Alpes 38041 Grenoble Cedex 9, France
- CNRS, UMR-5250 Département
de Chimie Moléculaire, Laboratoire de Chimie Inorganique Redox, Institut de Chimie Moléculaire de Grenoble, FR-CNRS-2607, BP-53, 38041 Grenoble Cedex 9, France
| | - Caroline Marchi-Delapierre
- Univ Grenoble Alpes 38041 Grenoble Cedex 9, France
- CEA, iRTSV, LCBM, 38054 Grenoble, France
- CNRS, UMR 5249, Grenoble, France
| | - Carole Duboc
- Univ Grenoble Alpes 38041 Grenoble Cedex 9, France
- CNRS, UMR-5250 Département
de Chimie Moléculaire, Laboratoire de Chimie Inorganique Redox, Institut de Chimie Moléculaire de Grenoble, FR-CNRS-2607, BP-53, 38041 Grenoble Cedex 9, France
- TGE Réseau National de RPE interdisciplinaire, FR-3443, 75231 Paris Cedex 05, France
| |
Collapse
|
10
|
Maurya MR, Haldar C, Kumar A, Kuznetsov ML, Avecilla F, Costa Pessoa J. Vanadium complexes having [VO]2+, [VO]3+ and [VO2]+ cores with hydrazones of 2,6-diformyl-4-methylphenol: synthesis, characterization, reactivity, and catalytic potential. Dalton Trans 2013; 42:11941-62. [DOI: 10.1039/c3dt50469g] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
|
11
|
Datta S, Seth DK, Butcher RJ, Bhattacharya S. Mixed-ligand thiosemicarbazone complexes of nickel: Synthesis, structure and catalytic activity. Inorganica Chim Acta 2011. [DOI: 10.1016/j.ica.2011.08.005] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
12
|
Chang YH, Su CL, Wu RR, Liao JH, Liu YH, Hsu HF. An Eight-Coordinate Vanadium Thiolate Complex with Charge Delocalization between V(V)−Thiolate and V(IV)−Thiyl Radical Forms. J Am Chem Soc 2011; 133:5708-11. [DOI: 10.1021/ja2004208] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
13
|
El-Sonbati AZ, Belal AAM, Diab MA, Balboula MZ. Polymer complexes. LVIII. Structures of supramolecular assemblies of vanadium with chelating groups. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2011; 78:1119-1125. [PMID: 21227746 DOI: 10.1016/j.saa.2010.12.063] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Revised: 12/06/2010] [Accepted: 12/14/2010] [Indexed: 05/30/2023]
Abstract
Oxovanadium(IV) polymer complexes of formulation {[(VO)L](2)}(n) (1) and [(VO)LB](n) (2-4), where H(2)L is tridentate and dianionic ligand (allylazorhodanine) and B is planar heterocyclic and aliphatic base have been prepared and characterized by elemental analyses, IR, (1)H NMR, electronic spin resonance spectra, magnetic susceptibility measurements, molar conductance and thermal studies. The molecular structure shows the presence of a vanadyl group in six-coordinate VNO(3)/VN(3)O(3) coordination geometry. The N,N-donor heterocyclic and aliphatic bas displays a chelating mode of binding with an N-donor site trans to the vanadyl oxo-group. In all polymeric complexes (1-4) the ligand coordinates through oxygen of phenolic/enolic and azodye nitrogen. The molar conductivity data show them to be non-electrolytes. All the polymer complexes are ESR active due to the presence of an unpaired electron. The calculated bonding parameters indicate that in-plane σ bonding is more covalent than in-plane π bonding. From the electronic, magnetic and ESR spectral data suggest that all the oxovanadium(IV) polymer complexes have distorted octahedral geometry. The thermal decomposition process of the polymeric complexes involves three decomposition steps.
Collapse
Affiliation(s)
- A Z El-Sonbati
- Chemistry Department, Faculty of Science, (Demiatta), Mansoura University, Egypt.
| | | | | | | |
Collapse
|
14
|
Chumakov YM, Janneau E, Bejenari NP, Tsapkov VI, Gulea AP. Crystal structure of copper sulfate and thiocyanate complexes with 5-bromo-and 5-nitrosalicylaldehyde thiosemicarbazones. RUSS J COORD CHEM+ 2011. [DOI: 10.1134/s1070328408010089] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
15
|
Gao YG, Zhou YZ, Dai YD, Yang XH. A binuclear oxovanadium(V) complex containing a tetrasulphido bridging ligand: synthesis, characterization, mechanism, TG-DTA analysis and UV–Vis spectra. J COORD CHEM 2010. [DOI: 10.1080/00958970902737432] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Yang Guang Gao
- a Department of Chemistry , Capital Normal University , Beijing 100048, China
| | - Yin Zhuang Zhou
- a Department of Chemistry , Capital Normal University , Beijing 100048, China
| | - Ying Di Dai
- a Department of Chemistry , Capital Normal University , Beijing 100048, China
| | - Xiao Hui Yang
- a Department of Chemistry , Capital Normal University , Beijing 100048, China
| |
Collapse
|
16
|
Hazari SK, Kopf J, Palit D, Rakshit S, Rehder D. Oxidovanadium(IV) complexes containing ligands derived from dithiocarbazates – Models for the interaction of VO2+ with thiofunctional ligands. Inorganica Chim Acta 2009. [DOI: 10.1016/j.ica.2008.06.020] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
17
|
Çakır S, Odabaşoğlu M, Biçer E, Yazar Z. Synthesis, spectroscopic and voltammetric studies of a novel Schiff-base of cysteine and saccharin. J Mol Struct 2009. [DOI: 10.1016/j.molstruc.2008.07.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
18
|
Rubčić M, Milić D, Horvat G, Đilović I, Galić N, Tomišić V, Cindrić M. Vanadium-induced formation of thiadiazole and thiazoline compounds. Mononuclear and dinuclear oxovanadium(v) complexes with open-chain and cyclized thiosemicarbazone ligands. Dalton Trans 2009:9914-23. [DOI: 10.1039/b913653c] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
19
|
Seena E, Mathew N, Kuriakose M, Kurup MP. Synthesis, spectral and EPR studies of oxovanadium(IV) complexes incorporating tridentate ONO donor hydrazone ligands: Structural study of one oxovanadium(V) complex. Polyhedron 2008. [DOI: 10.1016/j.poly.2008.01.020] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
20
|
Odunola OA, Woods JAO. SYNTHESIS, ELECTRONIC, AND MAGNETIC PROPERTIES OF SOME 3-SUBSTITUTED 2,4-PENTANEDIONATOOXOVANADIUM(IV) COMPLEXES AND THEIR 4-METHYLPYRIDINE ADDUCTS. ACTA ACUST UNITED AC 2007. [DOI: 10.1081/sim-100106865] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- O. A. Odunola
- a Department of Chemistry , University of the North , Private Bag X1106, Sovenga, 0727, South Africa
| | - J. A. O. Woods
- b Department of Chemistry , University of Ibadan , Ibadan, Nigeria
| |
Collapse
|
21
|
Demirci T, Köseoğlu Y, Güner S, Ülküseven B. Oxovanadium(IV) complexes of bromo-and methoxy substituted N1,N4-diarylidene-S-methylthiosemicarbazones. OPEN CHEM 2006. [DOI: 10.1007/s11532-005-0011-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
AbstractFour new oxovanadium(IV) compounds were prepared by template reaction of salicyl-, 5-bromosalicyl-and 3-methoxysalicyl-aldehyde S-methylthiosemicarbazones with 2-hydroxy-, 5-bromo-2-hydroxy-and 3-methoxy-2-hydroxy-benzaldehyde in various combinations. The compounds were isolated as stable solid compounds with general formula [VO(L)] and characterized by elemental analysis, conductivity and magnetic measurements, electronic, IR and EPR spectroscopy. The X-band EPR signals recorded from powder forms of all samples have a single asymmetric line shape and theoretical fit studies proved the presence of axial symmetry around the paramagnetic vanadium ions. The anisotropic Lande splitting factors take values of g‖ < g⊥ < ge = 2.0023. Orbital energy levels for magnetic electrons were determined from theoretically well fitted Spin Hamiltonian parameters. The EPR spectra recorded from solution forms almost have isotropic character.
Collapse
Affiliation(s)
- Tülay. Demirci
- 1Department of Chemistry, Istanbul University, 34320, Avcilar Istanbul, Turkey
| | - Yüksel Köseoğlu
- 2Department of Physics, Fatih University, 34500, Buyukcekmece Istanbul, Turkey
| | - Sadik Güner
- 2Department of Physics, Fatih University, 34500, Buyukcekmece Istanbul, Turkey
| | - Bahri Ülküseven
- 1Department of Chemistry, Istanbul University, 34320, Avcilar Istanbul, Turkey
| |
Collapse
|
22
|
Hsu HF, Su CL, Gopal NO, Wu CC, Chu WC, Tsai YF, Chang YH, Liu YH, Kuo TS, Ke SC. Redox Chemistry in the Reaction of Oxovanadium(V) with Thiolate-Containing Ligands: the Isolation and Characterization of Non-Oxo Vanadium(IV) Complexes Containing Disulfide and Thioether Groups. Eur J Inorg Chem 2006. [DOI: 10.1002/ejic.200500874] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
23
|
Rosenthal E, Cui H, Lange K, Dechert S. Synthesis, Molecular Structure, and Olefin Polymerisation Activity of an Oxovanadium(V) Alkoxide with Unprecedented Chloride Bridging Ligands. Eur J Inorg Chem 2004. [DOI: 10.1002/ejic.200400451] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
24
|
Elias H, Schwartze-Eidam S, Wannowius KJ. Kinetics and mechanism of ligand substitution in bis(N-alkylsalicylaldiminato)oxovanadium(IV) complexes. Inorg Chem 2003; 42:2878-85. [PMID: 12716179 DOI: 10.1021/ic020682m] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Conventional and stopped-flow spectrophotometry was used to to study the kinetics of ligand substitution in a number of bis(N-alkylsalicylaldiminato)oxovanadium(IV) complexes (=VO(R-X-sal)(2)) by 1,1,1- trifluoropentane-2,4-dione (=Htfpd) in acetone, according to the following reaction: VO(R-X-sal)(2) + 2Htfpd --> VO(tfpd)(2) + 2R-X-salH. The acronym R-X-salH refers to N-alkylsalicylaldimines with substituents X = H, Cl, Br, CH(3), and NO(2) in the 5-position of the salicylaldehyde ring and N-alkyl groups R = n-propyl, isopropyl, phenyl, and neopentyl. Under excess conditions ([Htfpd](0) >> [VO(R-X-sal)(2)](0)), substitution by Htfpd occurs in two observable steps, as characterized by pseudo-first-order rate constants k(obsd(1)) and k(obsd(2)). Both rate constants increase linearly with [Htfpd](0) according to k(obsd(1)) = k(s(1)) + k(1)[Htfpd](0) and k(obsd(2)) = k(s(2)) + k(2)[Htfpd](0), with k(s(1)) and k(s(2)) describing small contributions of solvent-initiated pathways. Depending on the nature of R and X, second-order rate constants k(1) and k(2) lie in the range 0.098-0.87 M(-1) s(-1) (k(1)) and 0.022-0.41 M(-1) s(-1) (k(2)) at 298 K. For ligand substitution in the system VO(n-propyl-sal)(2)/Htfpd, the activation parameters DeltaH++ = 35.8 +/- 2.8 kJ mol(-1) and DeltaS++ = -146 +/- 23 J K(-1) mol(-1) (k(1)) and DeltaH++ = 40.2 +/- 1.3 kJ mol(-1) and DeltaS++ = -142 +/- 11 J K(-1) mol(-1) (k(2)) were obtained. The Lewis acidity of the complexes VO(n-propyl-X-sal)(2) with X = H, Cl, Br, CH(3), and NO(2) was quantified spectrophotometrically by determination of equilibrium constant K(py), describing the formation of the adduct VO(n-propyl-X-sal)(2).pyridine. The adduct VO(tfpd)(2).n-propyl-salH, formed as product in the system VO(n-propyl-sal)(2)/Htfpd, was characterized by its dissociation constant, K(D) = (3.30 +/- 0.10) x 10(-3) M. The mechanism suggested for the two-step substitution process is based on initial formation of the adducts VO(R-X-sal)(2).Htfpd (step 1) and VO(R-X-sal)(tfpd).Htfpd (step 2).
Collapse
Affiliation(s)
- Horst Elias
- Eduard Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, Petersenstrasse 18, D-64287 Darmstadt, Germany.
| | | | | |
Collapse
|
25
|
Maurya M, Khurana S, Shailendra, Azam A, Zhang W, Rehder D. Synthesis, Characterisation and Antiamoebic Studies of Dioxovanadium(V) Complexes Containing ONS Donor Ligands Derived from S-Benzyldithiocarbazate. Eur J Inorg Chem 2003. [DOI: 10.1002/ejic.200200642] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
26
|
Dutta SK, Samanta S, Ghosh D, Butcher RJ, Chaudhury M. Oxovanadium(V) and cobalt(III) complexes of dithiocarbazate-based Schiff base ligands: formation of a thiadiazole ring by vanadium-induced cyclization of the coordinated ligand. Inorg Chem 2002; 41:5555-60. [PMID: 12377053 DOI: 10.1021/ic0200895] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
S-Methyl 3-((2-hydroxyphenyl)methyl)dithiocarbazate (H(2)L(1)) and its bromo derivative (H(2)L(2)), which are traditionally biprotic tridentate (ONS) ligands, behave in an unprecedented manner when allowed to react with [VO(acac)(2)] under an oxidative environment in acetonitrile-water medium containing a catalytic amount of alkali metal ion. The products obtained are oxovanadium(V) compounds [VOL(L(cyclic))] (L = L(1), 1a, and L(2), 1b) that contain one molecule of ligand which undergoes metal-induced cyclization to form a thiadiazole ring. Compound 1a crystallizes in the triclinic space group P(-)1 with a = 9.1830(9) A, b = 9.4165(12) A, c = 12.700(2) A, alpha = 100.988(8)(o), beta = 100.195(7)(o), gamma = 78.774(8)(o), V = 1046.3(2) A(3), and Z = 2. With cobalt(III), however, the products [CoL(HL)].H(2)O (L = L(1), 2a, and L(2), 2b) have hydrogen-bonded dimeric structures with each ligand virtually carrying 1.5 units of negative charge as confirmed by X-ray crystal structure analysis of 2a. It also crystallizes in triclinic space group P(-)1 with a = 12.0842(8) A, b = 13.5251(9) A, c = 14.1960(10) A, alpha = 78.122(6)(o), beta = 73.888(6)(o), gamma = 78.255(6)(o), V = 2154.7(3) A(3), and Z = 4. In solution, 2a is a symmetric molecule as indicated by (1)H NMR, involving a characteristic hydrogen-bonded O-H-O broad feature in the downfield (at 14.5 ppm) connecting both monoprotonated (LH(-)) and deprotonated (L(2-)) forms of the ligand--a situation somewhat analogous to the classic H-F-H case as observed in bifluoride ion.
Collapse
Affiliation(s)
- Subodh Kanti Dutta
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata 700 032, India
| | | | | | | | | |
Collapse
|
27
|
Maurya M, Khurana S, Zhang W, Rehder D. Vanadium(IV/V) Complexes Containing [VO]2+, [VO]3+, [VO2]+ and [VO(O2)]+ Cores with Ligands Derived from 2-Acetylpyridine andS-Benzyl- orS-Methyldithiocarbazate. Eur J Inorg Chem 2002. [DOI: 10.1002/1099-0682(200207)2002:7<1749::aid-ejic1749>3.0.co;2-g] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
28
|
Maurya MR, Khurana S, Zhang W, Rehder D. Biomimetic oxo-, dioxo- and oxo-peroxo-hydrazonato-vanadium(iv/v) complexes. ACTA ACUST UNITED AC 2002. [DOI: 10.1039/b202852m] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|