The paramagnetic cis dioxo molybdenum(V) complex, [NH 2~CH 2~CH 2~NH 3] 3[Mo VO 2(HNC 6H 4O) 2] was obtained by the reaction of tetra butyl ammonium β octamolybdate with o aminophenol a...The paramagnetic cis dioxo molybdenum(V) complex, [NH 2~CH 2~CH 2~NH 3] 3[Mo VO 2(HNC 6H 4O) 2] was obtained by the reaction of tetra butyl ammonium β octamolybdate with o aminophenol and ethylenediamine in the mixed solvent of CH 3OH and CH 3CN, and characterized by IR, NMR, EPR spectroscopy and X ray diffraction analysis. The determination of single crystal X ray analysis revealed that the central Mo V ion metal center exhibits distorted octahedral coordination with cis dioxo o aminophenol. The EPR spectra of both the complex and flavoenzyme show similarly. Thus it suggests that the complex anion [Mo VO 2(HNC 6H 4O) 2] 3- and flavoenzyme have related structure feature.展开更多
EPR spectra of four new gadolinium complexes with Schiff bases in polycrystalline powder and those of these complexes in three organic solvents were investigated at different temperatures. It has been observed for the...EPR spectra of four new gadolinium complexes with Schiff bases in polycrystalline powder and those of these complexes in three organic solvents were investigated at different temperatures. It has been observed for the first time that their freezing solution spectra are quite different from each other. In THF one peak was observed only, but there were three peaks and typical "U" spectral features appearing in DMF and DMSO at low temperatures. On the basis of spin Hamiltonian of S = 7/2 system, the correlations between crystal field strength in complexes and local symmetry around Gd3+ ions are discussed.展开更多
The EPR spectra of three new gadolinium complexes with noncyclic polyether Schiff bases in powder and those of these complexes in organic solvents were investigated at different temperatures. It was observed that EPR ...The EPR spectra of three new gadolinium complexes with noncyclic polyether Schiff bases in powder and those of these complexes in organic solvents were investigated at different temperatures. It was observed that EPR spectra of nine and four peaks of Gd(Ⅲ) complexes in polycrystalline powder and freezing samples appeared at low temperature respectively for the first time. The interpretations of these results obtained on the basis of spin Hamiltonian of s = 7/2 system are satisfactory. The correlations of EPR feature between crystal-field strength in complexes and local symmetry around Gd3+ ions were revealed. The crystal-field parameters b20 and the asymmetry parameters λ’ of complexes were estimated. A series of interesting regularity and new results were obtained.展开更多
A new Schiff base derived from tyrosine and salicylidene and its copper(Ⅱ ) complex have been synthesized and characterized by elemental analyses,molar conductances,thermal analyses,infrared spectra,electronic spectr...A new Schiff base derived from tyrosine and salicylidene and its copper(Ⅱ ) complex have been synthesized and characterized by elemental analyses,molar conductances,thermal analyses,infrared spectra,electronic spectra and EPR spectra.The composition of the complex is K[CuL(Ac)]· H2O, where L=H13C16NO4. EPR spectra of the copper(Ⅱ ) complex were investigated in various solvents at different temperatures.It is found that the linewidth of four hyperfine lines on solution spectra at room temperature is unequal and changes with mⅠ ,this could be satisfactorily explained by the relaxation effect.The relaxation time and the relaxation rate were calculated.By using spectral parameters from solution spectra at low temperature,the bonding parameters of Cu(Ⅱ ) complex were calculated.The bonding characterization and stability of the complex were disscussed.The results show that the in-planeσ-bond and the in-planeπ-bond in the complex all play an important role.展开更多
基金theNaturalScienceFoundationofBeijingProvince (No .2 0 12 0 0 5 )theNaturalScienceFoundationofEduca tionalMinistryofBeijing
文摘The paramagnetic cis dioxo molybdenum(V) complex, [NH 2~CH 2~CH 2~NH 3] 3[Mo VO 2(HNC 6H 4O) 2] was obtained by the reaction of tetra butyl ammonium β octamolybdate with o aminophenol and ethylenediamine in the mixed solvent of CH 3OH and CH 3CN, and characterized by IR, NMR, EPR spectroscopy and X ray diffraction analysis. The determination of single crystal X ray analysis revealed that the central Mo V ion metal center exhibits distorted octahedral coordination with cis dioxo o aminophenol. The EPR spectra of both the complex and flavoenzyme show similarly. Thus it suggests that the complex anion [Mo VO 2(HNC 6H 4O) 2] 3- and flavoenzyme have related structure feature.
基金Project supported by the National Natural Science Foundation of China and the Natural Science Foundation of Zhejiang Province.
文摘EPR spectra of four new gadolinium complexes with Schiff bases in polycrystalline powder and those of these complexes in three organic solvents were investigated at different temperatures. It has been observed for the first time that their freezing solution spectra are quite different from each other. In THF one peak was observed only, but there were three peaks and typical "U" spectral features appearing in DMF and DMSO at low temperatures. On the basis of spin Hamiltonian of S = 7/2 system, the correlations between crystal field strength in complexes and local symmetry around Gd3+ ions are discussed.
文摘The EPR spectra of three new gadolinium complexes with noncyclic polyether Schiff bases in powder and those of these complexes in organic solvents were investigated at different temperatures. It was observed that EPR spectra of nine and four peaks of Gd(Ⅲ) complexes in polycrystalline powder and freezing samples appeared at low temperature respectively for the first time. The interpretations of these results obtained on the basis of spin Hamiltonian of s = 7/2 system are satisfactory. The correlations of EPR feature between crystal-field strength in complexes and local symmetry around Gd3+ ions were revealed. The crystal-field parameters b20 and the asymmetry parameters λ’ of complexes were estimated. A series of interesting regularity and new results were obtained.
文摘A new Schiff base derived from tyrosine and salicylidene and its copper(Ⅱ ) complex have been synthesized and characterized by elemental analyses,molar conductances,thermal analyses,infrared spectra,electronic spectra and EPR spectra.The composition of the complex is K[CuL(Ac)]· H2O, where L=H13C16NO4. EPR spectra of the copper(Ⅱ ) complex were investigated in various solvents at different temperatures.It is found that the linewidth of four hyperfine lines on solution spectra at room temperature is unequal and changes with mⅠ ,this could be satisfactorily explained by the relaxation effect.The relaxation time and the relaxation rate were calculated.By using spectral parameters from solution spectra at low temperature,the bonding parameters of Cu(Ⅱ ) complex were calculated.The bonding characterization and stability of the complex were disscussed.The results show that the in-planeσ-bond and the in-planeπ-bond in the complex all play an important role.
