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.

Nonheme Oxovanadium(V,IV) Complexes Catalyze the Oxidative Cleavage of Catechols

It was found that the oxovanadium(V) complex of triethanolamine (TEA) exhibits catalytic activity to the oxidative cleavage of catechols. On the other hand. the vanadyl nitrilotriacetic acid (NTA) complex is inactive. but leads to the formation of stable ternary complex. The main products of the catalytic oxidative cleavage of 3.5-di-tert-butylcatechol were separated and characterized. Based on the results. a reaction mechanism was discussed

Photocleavage Properties and DNA-Binding Studies of Oxovanadium Complexes Incorporating 2-(2-Hydroxybenzylideneamino) Isoindoline-1,3-Dione and Fluoro-Phenanthroline Derivatives

Three mononuclear oxovanadium complexes [VO(Hbid)(CF3PIP)] (1) (Hbid=(E)-2-(2-hydroxybenzylideneamino) isoindoline-1,3-dione, CF3PIP=2-(2-trifluoromethyl phenyl)imidazole[4,5-f][1,10] phenanthroline), [VO(Hbid)(m-CF3PIP)];(2) (m-CF3PIP=2-(3-trifluoromethyl phenyl)imidazole [4, 5-f][1,10]phenanthroline) and [VO(Hbid)(p-CF3PIP)];(3) (p-CF3PIP=2-(4-trifluoromethyl phenyl) imidazole[4,5-f][1,10]phenanthroline) have been synthesized and characterized by elemental analysis, IR, molar conductance, ES-MS and 1H NMR. The DNA-binding properties of these complexes were studied by using UV-Vis absorption titration, fluorescence spectra, viscosity measurements and thermal denaturation studies. The results show that 1, 2 and 3 interact with calf thymus DNA (CT-DNA) by intercalation modes and the magnitude of their intrinsic binding constants (Kb values) follows the order: 2 < 1 < 3. Furthermore, their photocleavage properties with pBR322 plasmid DNA were investigated by agarose gel electrophoresis experiments. The DNA cleavage capacity of complex 3 is also stronger than that of 1 and 2.

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.

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.

Synthesis and crystal structure of sodium ammonium dimeric (citrato)dioxovanadium(V) Na_2(NH_4)_4[VO_2(cit)]_2·6H_2O

Recent crystallographic analysis of the metal centers in the nitrogenasemolybdenum-iron protein with 0.22 and 0.27 nm resolution revealed the structural model ofFeMo-cofactor as a cage-like cluster, in which molybdenum is chelated by hydroxy- andcarboxylate ligands of homocitrate. It is deduced that the homocitrate may be importantfor the substrate reduction mechanism. Considering that the central molybdenum of

Synthesis, Characterization and Antimicrobial Activity of Oxovanadium（IV） Complexes of Schiff Base Hydrazones Containing Quinoxaline Moiety

The oxovanadium（IV） complexes of the Schiff base hydrazones, synthesized from 3-hydrazinoquinoxaline-2- one （HQO） with salicylaldehyde （HSHQO）, o-hydroxyacetophenone （HHAHQO）, dehydroacetic acid （HDHAHQO） and o-nitrobenzaldehyde （NBHQO） were synthesized and characterized on the basis of analytical, conductance, magnetic moment, infrared, NMR, ESR and electronic spectral data. The ligands HSHQO, HDHAHQO behaved as monobasic tridentate ONN donors through phenolic oxygen, azomethine nitrogens. The ligand HAHQO acted as a monobasic bidentate ON donor through the phenolic oxygen, azomethine （free） nitrogen and the ligand NBHQO acted as neutral bidentate ON donor through oxygen of the nitro group and azomethine （free） nitrogen.

Glucose-lowering A ivity of Amino Acid- phosphonic Acid Oxovanadium Complexes and Its Interaction with DNA

Vanadium has well-documented lowering glucose properties both in vitro and in vivo. The design of new oxovanadium（IV） coordination compounds, intended for use as insulin-enhancing agents in the treatment of diabetes mellitus, can potentially benefit from a synergistic approach, in which the whole complex has more than an additive effect from its component parts. Biological testing with oxovanadium（IV） organic phosphonic acid, for insulin-enhancing potential included acute administration, by oral gavage in streptozotocin （STZ） diabetic rats. The complexes of oxovanadium（IV） amino acid-N-phosphonic acid exhibit higher lowering glucose activity in vivo. The interaction of the complexes of oxovanadium（IV） amino acid-N-phosphonic acid with DNA was investigated by agarose gel electrophoresis. The results indicated that these complexes have strong interaction with DNA.

Synthesis, Characterization and the Effect of Glucose-lowering of Guanidino Acid Oxovanadium(Ⅳ) Complexes

Two guanidino acid oxovanadium(IV) complexes have been synthesized. Preliminary tests in vivo have shown that the two title complexes all display lowering glucose activity in vivo to STZ-rats. The effect of glucose-lowering of guanidino acetic acid oxovanadium(IV) complex in vivo is higher than that of guanidino propanoic acid oxovanadium(IV) complex.

ESR SPECTRA OF SOME ACIDIC PHOSPHATE (PHOSPHONATE) OXOVANADIUM (Ⅳ) COMPLEXES

Acidic phosphate (phosphonate) ester can form coordination complexes with many metal ions. Sato, T. et al. have studied ESR spectra of the complexes formed in the extraction of oxovanadium from hydrochloric acid solutions by di-(2-ethylhexyl)-phosphoric acid (DEHPA), however better, resolving spectra cannot be obtained.

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, characterization and magnetic properties of μ-iodanilato dinuclear oxovanadium (Ⅳ) complexes

Five oxovanadium(Ⅳ) dinuclear complexes described by the overall formula [(VO)2(IA)L2]-SO4, where IA represents the dianion of iodanilic acid and L denotes 2,2'-bipyridine (bpy) ; 4,4'-dimethyl-2,2'-bipyridine (Me2-bpy); 1,10-phenanthroline (phen); 4,7-diphenyl-1, 10-phenanthroline (Ph2-phen) and 5-nitro-l, 10-phenanthroline (NO2-phen) , have been synthesized and characterized by elemental analyses, molar conductivity and room-temperature magnetic moment measurements, IR and electronic spectral studies. It is proposed that these complexes have IA-bridged structures and consist of two oxovanadium(Ⅳ) ions each in a square- pyramidal environment. The complexes [ ( VO)2 (IA) (bpy )2 ] SO4 (1) and [ ( VO )2 ( IA) ( phen)2 ] -SO4 (2) were further characterized by variable temperature (4.2-300 K) magnetic susceptibility measurements and the observed data were fitted to the modified Bleaney-Bowers equation by the least-squares method, giving the exchange integral J = -2.15 cm-1 for 1 and J = - 9.88 cm-1 for 2. This result indicates that there is a weak antiferromagnetic spin-exchange interaction between the two VO2+ ions within each molecule.

Studies on the synthesis and magnetic property of binuclear oxovanadium(Ⅳ) complexes ridged by chloranilato group

Six novel oxovanadium(IV) binuclear complexes have been synthesized and characterized,namely,[(VO)2(CA)La]SO4 [L denotes 5-methyl-l,10-phenanthroline (Me-phen);2,9-dimethyl-1,10-phenanthroline (Me2-phen); 5-chloro-l,10-phenanthroline (Cl-phen); diaminoethane (en); 1,3-diaminopropane (pn) and 1,2-diaminopropane (ap) respectively.],where CA represents the dianion of chloranilic acid.Based on elemental analyses,molar conductivity and room temperature magnetic moment measurements,IR and electronic spectral studies,it is proposed that these complexes have CA-bridged structures and consist of two vanadium(IV) ions in a square-pyramidal environment.The complexes [(VO)2(CA)(Me-phen)2]SO4 (1) and [(VO)2(CA)(Me2-phen)2]SO4 (2) were characterized by variable temperature magnetic susceptibility measurements (4~300 K) and the observed data were fitted to the modified Bleaney-Bowers equation by the least-squares method,giving the exchange integral J=-15.8 cm-1 for 1 and J=-10.6 cm-1 for 2.This result indicates that t

Synthesis and characteriza-tion of two new types of oxovanadium complexes with pyrazole as ligand

At room temperature, two new different oxovanadium complexes with simple pyrazole (C3H4N2) as ligand were synthesized. VO(pz)4(SO4)? H2O (1) (pz: pyrazole) is a mono-nuclear oxovana- dium complex with pyrazole as terminal ligands. V2O2(μ-pz)(μ-OOSO2)(μ-OCH3)(pz)4 (2) is bi-nuclear oxovanadium complex containing three different bridges, which are pyrazolate, sulphate and methoxy, respectively. The two complexes were characterized by IR, elemental analyses, thermal analyses and X-ray diffraction. The crystal structural data of the complexes 1 and 2 are given as follows: Complex 1, orthorhombic, Pna21, a = 14.547(2) ?, b =10.895(2) ?, c =11.835(2) ?; α=β=γ=90°, V=1875.8(5) ?3, Z = 4, R1 = 0.0485, WR2 = 0.1092. Complex 2, triclinic, P1 , a =8.377(2) ?, b =9.928(2) ?, c = 16.527(3) ?, α = 85.54(3)°, β = 80.92(3)°, γ = 87.92(3)°, R1 = 0.1461, WR2 = 0.4444. The study of non-thermal kinetic de- composition shows that, for complex 1, the possible reaction mechanisms of the two steps are nucleation and growth n=1/3, and three-dimensional pervasion n=2, respectively, and the kinetic equations may be expressed as dα/dT = (A/β)exp(?E/RT){1/3(1?α) [?In(1?α)]?2} and dα/dT = (A/β)exp(?E/RT){3/2(1?α)2/3 [1?(1?α)1/3] ?1}, respectively; for complex 2, the pos- sible reaction mechanisms of the two steps are chemical reaction, and three-dimensional pervasion n=2, respectively; the kinetic equations may be ex- pressed as dα/dT = (A/β)exp(?E/RT)[(1?α)2], anddα/dT = (A/β)exp(?E/RT){3/2(1?α)2/3[1?(1?α)1/3] ?1}, respectively.

Synthesis, spectra, structure and quantum chemistry study on two novel oxovanadium complexes with hydrotris (pyrazolyl) borate ligands

Two novel oxo-vanadium complexes of VO(HB(pz)3)(pzH)(SCN) (1) and VO(HB(3,5-Me2pz)3) (3,5-Me2pzH)(SCN)(SCNH)2 (2) with tris(pyrazolyl) hydroborate ligands were prepared by the reaction of VOSO4?nH2O, KSCN with Na(HB(pz)3), pyrazole, or Na(HB(3,5-Me2pz)3) and methyl-substituted pyrazole in the solution of MeOH, respectively. The complexes were characterized by element analysis, IR, and UV- vis spectra. In the mean time, the fluorescence spec-trum was studied too, and the result indicates that the luminescence of the complexes is related to the in-teraction between oxovanadium ion and tris(pyra- zolyl) hydroborate ligands. In addition, structures of oxovanadium complexes 1 and 2 were determined by X-ray diffraction. The electronic structures and the bonding characters of the two complexes were ana-lyzed with ab initio calculations.

蝎型钒氧苯甲酸配合物的合成、结构及量化计算

设计合成了两种以聚吡唑硼酸盐、苯甲酸为配体的钒氧配合物VO[HB(pz)3](pzH)(C6H5COO)(1)和VO[HB(3,5-Me2pz)3](3,5-Me2pzH)(C6H5COO)(2)((HB(pz)3:聚吡唑硼酸钠盐;pzH:吡唑;HB(3,5-Me2pz)3:聚甲基吡唑硼酸钠盐;3,5-Me2pzH:3,5-二甲基吡唑).通过元素分析、红外光谱和X射线单晶衍射方法对配合物进行了表征.并结合从头计算结果进一步分析了配合物的稳定性及分子中配键的共价特征.分析结果表明,配合物2的稳定性大于配合物1,中心钒原子周围的价键类型都属于共价键范畴,键序分析结果与晶体结构测定的键长结果是一致的.

双(α-呋喃甲酸)氧钒的合成和抗糖尿病活性研究

设计和合成了一种新型的有机羧酸氧钒配合物双 (α 呋喃甲酸 )氧钒 .运用元素分析、红外光谱、紫外光谱、质谱和核磁共振氢谱对配合物的结构进行了初步确证 .在实验性动物模型上研究了这个配合物的初步毒性和降血糖作用 .结果表明 :双 (α 呋喃甲酸 )氧钒具有活性高 ,安全性好的优点 。

双(α-呋喃甲酸)氧钒对糖尿病大鼠血糖的调节作用

目的 研究双(α- 呋喃甲酸)氧钒(VO FA)对正常大鼠及链脲佐霉素(STZ)性糖尿病大鼠的降糖作用。方法 以STZ诱导大鼠糖尿病模型。观察VO FA灌胃给药后,对血糖、糖化血红蛋白、糖原和血清胰岛素等的影响。结果 VO FAig两周后,剂量依赖性地降低STZ性糖尿病动物的血糖水平,但对正常动物的血糖无影响。VO FA56 8mg·kg-1可降低正常动物血清胰岛素水平,加倍剂量尚能降低STZ性糖尿病大鼠的血清胰岛素水平。此外,VO FA能降低糖尿病大鼠的糖化血红蛋白,明显改善糖耐量,增加肌糖原和肝糖原的含量,并呈现出量效关系,但对正常动物则没有影响。结论 VO FA可以改善糖尿病动物的糖代谢,而不影响正常动物的血糖水平。

Schiff碱氧钒配合物、载药脂质体的合成和抑瘤活性研究

合成了3个水杨醛Schiff碱氧钒配合物.采用元素分析、红外光谱和51VNMR谱等对配合物结构进行了表征.并进行了载药脂质体的粒径粒度分析和表观形貌观察,比较研究了配合物及载药脂质体的红外光谱和肝肿瘤细胞的抑制作用.结果表明:在氧钒配合物脂质体的红外光谱中,氧钒配合物的特征振动峰仍然存在,在载药脂质体形成后,氧钒配合物的基本骨架没有发生变化,但由于弱相互作用导致V=O振动峰增强并发生蓝移;随着试药浓度的增加,配合物和载药脂质体对肿瘤细胞的抑制率均明显增加,但同浓度的配合物和载药脂质体比较,前者对肝肿瘤细胞的抑制能力明显低于后者,可能与载药脂质体具有更强的细胞钻透能力有关,而更易于将药物传输到作用部位.

微波辐射下苯并噻吩的氧化脱硫研究

将苯并噻吩(BT)溶于正辛烷配成模型油,以H2O2为氧化剂,研究微波辐射作用下磷钼酸镧盐和磷钼酸氧化钒(IV)盐催化模型油的氧化脱硫。结果表明,在微波功率为400 W和温度为70℃的条件下反应90min,用磷钼酸镧盐催化,脱硫率可达89.6%,而用磷钼酸氧化钒(IV)盐催化,脱硫率仅为48.7%。催化剂用量、H2O2初始浓度、反应温度和反应时间等因素对模型油的氧化脱硫均有影响。