The Mo(Ⅴ) and W(Ⅵ) complexes of (NH3CH2- CH2NH2)3[Mo(Ⅴ)O2(OC6H4O)2] (1), (NH3CH2CH2NH2)2.5 [Mo(Ⅴ) 0.5W(Ⅵ)0.5O2(OC6H4O)2] (2) and (NH3CH2CH2NH2)2- [W(Ⅵ)O2(OC6H4O)2] (3) were synthesized by choosing cate-chol ligand which shows a good reductive property and tak-ing advantage of EMo > EW. Their EPR and UV-vis spectra were compared with the oxidized UV-vis spectra of xanthine dehydrogenase from chicken liver and xanthine oxidase from milk and the EPR spectrum of flavoenzyme from milk.
LU XiaomingLIU ShunchengMAO XiYE ZhaohuiLU Jingfen
The reaction of palladium chloride with isovanillin semithiocarbazone (VSTC), CH3O(OH)C6H3CH=NNC(S)NH2, in a mixed solvent of ethanol, pyridine and water yielded the mononuclear palladium(Ⅱ) complex Pd[CH3O(O)C6H3CHNNC(S)NH2](C5H5N), and its single- crystal structure was determined by X-ray diffraction. The crystal belongs to triclinic, space group P with a = 7.715(4), b = 9.809(6), c = 10.612(4) ? a = 93.54(4), b = 111.00(3), g = 95.92(5), V = 745.0(7) 3, Mr = 408.75, Z = 2, Dc = 1.822 g/cm3, m = 1.397 mm-1, and F(000) = 408. The final R = 0.0568 and wR = 0.1439 for 2616 observed independent reflections with I ≥ 2.0s(I). It was revealed that the palladium atom is bound to a tridentate donor ligand and a pyridine in a planar square arrangement. The sulphur-nitrogen-oxygen donor of the Schiff-base ligand in the thiol form rather than the thione one is coordinated to the palladium atom via the mercapto sulphur, the b-nitrogen and the hydroxylate oxygen atoms.
Cis-dioxo-catecholatotungsten(V) complex (NH2CH2CH2NH3)4[WⅤO2(OC6H4O)2]2(NH3CH2CH2NH3)·H2O (1) was synthesized at room temperature by the reaction of tetrabutyl ammonium decatungstate with catechol in the mixed solvent of CH3OH, CH3CN and NH2CH2CH2NH2. The crystal structure of complex was determined by X-ray diffraction structural analysis. The results show that complex belongs to monoclinic system with space group P21 / c, a=0.712 8(3) nm, b=3.082 3(11) nm, c=0.982 8(4) nm, β=102.639(6)°, V=2.106 8(14) nm3, Z=2, R1=0.062 8, wR2=0.183 7. Compared the complex with its analogous complexes (NH2CH2CH2NH3)3[MoⅤO2(OC6H4O)2], it is found that the coordination structure of W have no changes in the processing of electron transfer of tungsten-containing enzymes from the result of the similarity of the EPR spectra of the complexes and flavoenzyme from milk. CCDC: 272937.
A novel super-molecular complex, [Na(DB18C6)(CH3CN)]2Mo6O19, was obtained by solvothermal reaction and characterized by elementary analysis, IR, 1H NMR, gumbc spectrum and X-Ray diffraction experiment. The compound crystallizes in monoclinic space group P21 / n with a=1.187 1(3) nm, b=2.096 3(6) nm, c=1.415 8(4) nm, β=110.854(5)° and Z=4. The complex contains four basic units: Na+, CH3CN, DB18C6和Mo6O192-. Sodium ions located in the cavity of dibenzo-18-crown-6 with 6 Na-O bonds and the crown ether-sodium ion complex is supported on the terminal oxygen atoms of the typical Lindqvist isopolyanion Mo6O192- via the coordinative interactions. Mo6O192- located between two DB18C6 and led to the formation of the "hamburger" structure. The crystal is stabilized by van der waals force and interaction of π-π system. CCDC: 272936.
Cis-dioxo-tungsten(Ⅵ ) complex, (NH2CH2CH2NH2)[(NH2CH2CH2NH3)2WⅥO2(NHC6H4NH)2]2·H2O is synthesized at room temperature by the reaction of sodium tungstate with o-phenylenediamine. The crystal structure of complex was determined by X-ray diffraction structural analysis. The results show that complex belongs to monoclinic system with space group P21 / c, a=0.712 8(2) nm, b=3.081 1(10) nm, c=0.981 9(3) nm, β=102.615(4)°, V=2.104 4(11) nm3, Z=2, μ=55.26 cm-1, F(000)=1 176. Compared the complex with its analogous biomimetic complexes of the cofactor of molybdoenzymes and tungstoenzymses, it is found that the variance of the coordination atoms and the metal ions center have no influence on the coordination feature, and exhibits distored octahedral coordination with cis-dioxo o-phenylenediamine. CCDC: 252834.
