New Square-Pyramidal Oxovanadium (IV) Complexes Derived from Polydentate Ligand (L1)

New series of oxovanadium (IV) complexes isolated from 2,4,6-tris-(2-pyridyl)-1,3,5-triazine (L1) are incorporated and portrayed using spectroscopic (IR, UV-Vis, ESR, mass spectrometric), magnetic moment, thermal and cyclic voltammetry measurements. The results demonstrate that L1 acts in various styles of chelation with [V3O3(L1)(SO4)3(EtOH)1/2(H2O)3/2] 1), [VO(L1)(2,4-pentadionate)]·Cl·4HCl 2), [V2O2(L1)(SO4)2(EtOH)5/2] 3), [V2O2(L1)(SO4)2(EtOH)3/2(H2O)1/2] 4), [VO(L1)SO4 (H2O)3/2]·2.5H2O 5) and [V2O2(L1)(SO4)2(H2O)]·H2O 6). The values of magnetic moments and spectral studies suggest a square-pyramidal geometry around the V (IV) ion for all complexes. The molar conductance values suggest that the complexes are non-electrolyte, except the [VO(L1) (2,4-pentadionate)] Cl·4HCl. Molecular modeling calculates the bond length, bond angle, chemical reactivity, energy components (Kcal/mol) and binding energy (Kcal/mol) for the isolated complexes. The in vitro antibacterial studies of these complexes screened against pathogenic bacteria prove them as growth inhibiting agents. Antitumor activity is carried out in vitro on human mammary gland (breast) MCF-7 and cervical cancer cell-HeLa has shown that [VO(L1)SO4(H2O)3/2]·2.5 H2O and [VO(L1)(2,4-pentadionate)] Cl·4HCl complexes display the highest powerful activity between all of the investigated complexes.

Syntheses and Crystal Structures of 3-Chloro-N'-(3,5-dichloro-2-hydroxybenzylidene)-benzohydrazide and Its Oxovanadium(V) Complex with Antimicrobial Activity

A hydrazone compound 3-chloro-N＇-（3,5-dichloro-2-hydroxybenzylidene）benzo-hydrazide（H2L） derived from the condensation of 3,5-dichlorosalicylaldehyde with 3-chloro-benzohydrazide and its oxovanadium（V） complex [VOL（CH3OH）（OCH3）] have been successfully prepared and characterized by physico-chemical methods and single-crystal X-ray diffraction.The hydrazone ligand coordinates to the V atom through the phenolate O,imine N,and enolic O atoms.The V atom is hexa-coordinated in a distorted octahedral geometry.The antimicrobial activities（MIC） of the hydrazone ligand and the oxovanadium（V） complex have been evaluated against the bacteria Staphylococcus aureus,Baccilus subtilis,Pseudomonas aeruginosa,and Escherichia coli.

Synthesis,Crystal Structure and Properties of Complex VO(C_(12)H_(12)N_2O_2)(C_(13)H_(10)NO_2)

Complex VO(C\-\{12\}H\-\{12\}N\-2O\-2)(C\-\{13\}H\-\{10\}NO\-2)(C\-\{12\}H\-\{12\}N\-2O\+\{\{\}\+\{2-\}\}\-2=acetylacetone benzoylhydrozanate,C\-\{13\}H\-\{10\}NO\+_\-2=\%N\%\|phenylbenzohydroxamate) was synthesized and characterized by means of elemental analysis,IR and UV spectroscopies,cyclic voltammetry and single crystal X\|ray diffraction. The complex crystallized in the monoclinic system with space group \%P\%2\-1/\%n\% and the crystal cell parameters \%a\%=1\^3003(1) nm,\%b\%=0\^88836(6) nm,\%c\%=2\^0196(2) nm,\%β\%=95\^065(8)°,\%V\%=2\^3238(3) nm\+3,\%M\%\-r=495\^40 and \%Z\%=4. The two oxygen and one nitrogen atoms of the tridentate hydrazone ligand coordinate to the vanadium atom,forming an equatorial plane. And the coordinated vanadium atom exhibits a distorted octahedral geometry. The atom in the transposition to the oxo O atom is the carbonyl oxygen atom of the hydroxamate ligand in the complex. The half\|wave redox potential of the title complex in the three different solvents positively shifts in the order of CH\-2Cl\-2<CH\-3CN<DMF.

Synthesis, Crystal Structure and Properties of Complex VO(C_(10)H_9NO_3)(C_(13)H_(10)NO_2)

Complex VO(C 10H 9NO 3)(C 13H 10NO 2)(C 10H 9NO 2- 3=N-salicylidene-L-alaninate, C 13H 10NO- 2=N-phenylbenzohydroxamate) was synthesized and characterized by means of elemental analysis, IR, UV, 1H NMR spectroscopies, cyclic voltammetry and single crystal X-ray diffraction. The complex crystallized in a monoclinic system with space group P2 1 and crystal cell parameters a=0.9720(1) nm, b=1.8274(2) nm, c=1.2542(1) nm, β=104.868(9)°, V=2.1532(4) nm3, M r=470.34, Z=2. The two oxygen atoms and the one nitrogen atom of the tridentate Schiff base ligand and the one oxime oxygen atom of the hydroxamate ligand coordinate to the vanadium atom, forming an equatorial plane, the two axial positions are respectively occupied by the oxygen atom of the oxovanadium and the carbonyl oxygen atom of the hydroxamate and the vanadium atom exhibits a distorted octahedral VO(ONO)(OO) coordination sphere. The 1H NMR spectrum suggests that the two isomers, endo and exo in a molar ratio of 1/1.7, coexist in the solution of the title complex in CDCl 3. There exists a quasi-reversible one-electron redox reaction corresponding to VⅤ/VⅥ couple in the three non-aqueous solvents, and the redox potential E 1/2 of the title complex substantially shifts in the direction of the positive voltage increase in the order: CH 2Cl 2<CH 3CN<DMF.

Synthesis and magnetic studies of phthalato-bridged oxovanadium(Ⅳ) binuclear complexes

Six new μ-phthalato binuclear oxovanadium(IV) complexes,namely [(VO)2(PHTH)-(L)2]SO4 (L denotes 2,2'-bipyridine (bpy);1,10-phenanthroline (phen);4,4'-dimethyl-2,2'-bipyridine (Me2bpy);5-nitro-1,10-phenanthroline (NO2-phen);5-chloro-1,10-phenanthroline (Cl-phen) and 5-methyl-l,10-phenanthroline (CH3-phen),where PHTH is the phthalate dianion),have been synthesized and characterized by elemental analyses,IR,electronic spectra,magnetic moments at room temperature and molar conductivity measurements.The temperature dependence of the magnetic susceptibility of complexes [(VO)2(PHTH)(Phen)2]SO4 (1) and [(VO)2(PHTH)(CH3-phen)2]SO4 (2) was measured in 4-300 K range and the observed data were successfully simulated by the equation based on the spin Hamiltonian operator,H--2JS1S2,giving the exchange integrals J=-12.8 cm-1 for 1 and J=-7.9 cm-1 for 2.This indicates an antiferromagnetic spin-exchange interaction between the metal ions within each molecule.

Synthesis and Crystal Structure of a New Oxovanadium（V） Multicomponent Complex with Acylhydrazone and Benzoylhydrazine

A new oxovanadium（V） complex with the mixed ligand of 2-oxopropionic acid benzoylhydrazone （C10H10N2O3） and benzoylhydrazine （C7H8N2O）, VO（C7H7N2O）（C10H9N2O3）, has been synthesized. Its structure was determined by single crystal X-ray diffraction analysis. The crystal belongs to monoclinic system with space group P21/n and cell parameters： a=1.1136（4） nm, b=0.6217（2） nm, c=2.6038（9） nm, β=97.182（6）°, V= 1.7887（11） nm^3, Z=4, F（000）=836, Mr=407.28, Dc= 1.512 g/cm^3,μ （Mo Kα） =0.592 mm^-1, R1 =0.0445, wR2= 0.1203. Vanadium atom is 6-coordinated by carboxyl and carbonyl O atoms and N atom of one tridentate C10H10N2O3 to form two stable five-membered rings with the same edge, and the other coordinated atoms of N and O come from one bidentate benzoylhydrazine C7H8N2O. The title complex has a six-coordinated V center [VO（N2O3）] with a distorted octahedral arrangement. In the crystal lattice, there are hydrogen bonding interactions between two molecules.