Vanadium compounds are promising anti-diabetic agents. However, the concern in the toxicity, especially the long-term renal side effect along with diabetic status, is restricting the further development of this metal ...Vanadium compounds are promising anti-diabetic agents. However, the concern in the toxicity, especially the long-term renal side effect along with diabetic status, is restricting the further development of this metal drug. Recently, we have prepared a bis（（5-hydroxy-4-oxo-4H-pyran-2-yl） methyl 2-hydroxy-benzoatato） oxovanadium（BSOV）, which exhibited excellent hypoglycemic effect with low acute toxicity. In order to facilitate the development of anti-diabetic vanadium complexes, especially BSOV, we studied the long-term toxicity and hypoglycemic effect of BSOV in comparison with bis（maltolato） oxovanadium（BMOV） on both non-diabetic and type II diabetic mice. The experiments confirmed a stable hypoglycemic effect for both the vanadium complexes over the testing period（6–7 months）. However, the chronic administration of vanadium compounds slightly increased oxidative stress in ICR mice and the induced renal interstitial edema（RIE） in a part of the diabetic animals associated with low levels of serum albumin. The use of an antioxidant dietary supplement（a combination of vitamin C and Zinc gluconate） could prevent vanadium-induced oxidative stress but have marginal effect on RIE. However, BSOV caused much lower incidence of RIE than BMOV did, suggesting that BSOV is an important step towards the successful development of anti-diabetic vanadium drugs.展开更多
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 ...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.展开更多
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...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.展开更多
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-lo...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.展开更多
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, U...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.展开更多
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-CF3P...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.展开更多
New series of oxovanadium (IV) complexes isolated from 2,4,6-tris-(2-pyridyl)-1,3,5-triazine (L<sup>1</sup>) are incorporated and portrayed using spectroscopic (IR, UV-Vis, ESR, mass spectrometric), magnet...New series of oxovanadium (IV) complexes isolated from 2,4,6-tris-(2-pyridyl)-1,3,5-triazine (L<sup>1</sup>) are incorporated and portrayed using spectroscopic (IR, UV-Vis, ESR, mass spectrometric), magnetic moment, thermal and cyclic voltammetry measurements. The results demonstrate that L<sup>1</sup> acts in various styles of chelation with [V<sub>3</sub>O<sub>3</sub>(L<sup>1</sup>)(SO<sub>4</sub>)<sub>3</sub>(EtOH)<sub>1/2</sub>(H<sub>2</sub>O)<sub>3/2</sub>] 1), [VO(L<sup>1</sup>)(2,4-pentadionate)]·Cl·4HCl 2), [V<sub>2</sub>O<sub>2</sub>(L<sup>1</sup>)(SO<sub>4</sub>)<sub>2</sub>(EtOH)<sub>5/2</sub>] 3), [V<sub>2</sub>O<sub>2</sub>(L<sup>1</sup>)(SO<sub>4</sub>)<sub>2</sub>(EtOH)<sub>3/2</sub>(H<sub>2</sub>O)<sub>1/2</sub>] 4), [VO(L<sup>1</sup>)SO<sub>4</sub> (H<sub>2</sub>O)<sub>3/2</sub>]·2.5H<sub>2</sub>O 5) and [V<sub>2</sub>O<sub>2</sub>(L<sup>1</sup>)(SO<sub>4</sub>)<sub>2</sub>(H<sub>2</sub>O)]·H<sub>2</sub>O 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(L<sup>1</sup>) (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(L<sup>1</sup>)SO<sub>4</sub>(H<sub>2</sub>O)<sub>3/2</sub>]·2.5 H<sub>2</sub>O and [VO(L<sup>1</sup>)(2,4-pentadionate)] Cl·4HCl complexes display the highest powerful activity between all of the investigated complexes.展开更多
VPO polymer β NH 4(VO 2)(HPO 4) was synthesized from the mixture of NH 4VO 3 and NH 4H 2PO 4 in aqueous acidic solution. This hydrogenphosphate vanadate crystallizes in the orthorhombic space group Pbca with a=0.680 ...VPO polymer β NH 4(VO 2)(HPO 4) was synthesized from the mixture of NH 4VO 3 and NH 4H 2PO 4 in aqueous acidic solution. This hydrogenphosphate vanadate crystallizes in the orthorhombic space group Pbca with a=0.680 60(8) nm, b=0.925 70(5) nm, c=1.773 70(2) nm, V=1.117 5(3) nm 3, Z=8, D c=1.743 g·cm -3 , μ=88.54 cm -1 and R=0.051. The structure is built up from VO 5 square pyramid linked by trans vertices through the bridged oxygen atom to form an one dimensional isolated chain of {VO 2HPO 4} n- nunning along the a axis.展开更多
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 solut...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.展开更多
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 inactiv...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展开更多
By using different organic ligands, two 3D inorganic-organic hybrid compounds Co（C4H4N2）（VO3）2 1 and Co（C12H12N2）（VO3）2 2 were synthesized by hydrothermal reaction and characterized by X-ray crystallography. C...By using different organic ligands, two 3D inorganic-organic hybrid compounds Co（C4H4N2）（VO3）2 1 and Co（C12H12N2）（VO3）2 2 were synthesized by hydrothermal reaction and characterized by X-ray crystallography. Crystal data： 1. crystal system orthorhombic, space group Pnna, a=1 0.188（2） A, b=1 1.497（2） A, c=7.3975（15） A, V=866.5（3） A^3, Z=4, Dcalcd= 2.705 g/cm^3; 2. crystal system triclinic, space group P1^- （No. 2）, a=8.3190（17） A, b=8.4764（17） A, c=1 1.183（2） A, a=95.48（3）°, β=92.03（3）°, γ=107.24（3）°,V=748.0（3） A^3, Z=2, Dcalcd= 1.958 g/cm^3. The framework of compound 1 contains both {Co（C4H4N2）} and infinite metavanadate chains. Crystal structure of compound 2 is constructed with inorganic {CoV2O6} layers across-linked by organic 1,2-bis（4-pyridyl） ethane ligands. The two compounds are thermally stable to approximately 410 ℃ and 350 ℃, respectively. Their optical band gaps are determined to be 2.13 eV and 2.12 eV by UV-VIS-NIR diffuse reflectance spectra, which revealed their nature of semiconductor and optical absorption features.展开更多
合成了一种新的L-天冬酰胺邻香草醛席夫碱和1,10-邻菲咯啉的氧钒配合物[VO(o-Van-L-Asn)(Phen)]1.5CH3OH(o-Van-L-Asn=邻香草醛与L-天冬酰胺形成的席夫碱,Phen=1,10-邻菲咯啉).利用红外光谱对其进行了表征,并通过X射线单晶衍射测定了其...合成了一种新的L-天冬酰胺邻香草醛席夫碱和1,10-邻菲咯啉的氧钒配合物[VO(o-Van-L-Asn)(Phen)]1.5CH3OH(o-Van-L-Asn=邻香草醛与L-天冬酰胺形成的席夫碱,Phen=1,10-邻菲咯啉).利用红外光谱对其进行了表征,并通过X射线单晶衍射测定了其晶体结构.该晶体属于三斜晶系,P-1空间群,晶胞参数为:a=0.98990(10)nm,b=1.21591(11)nm,c=1.28349(12)nm,α=66.8180(10)°,β=83.816(2)o,γ=66.4150(10)o,V=1.2992(2)nm3,Dc=1.430 g cm-3,Z=1,F(000)=580,R1=0.0626,wR2=0.1631.通过紫外吸收光谱、荧光光谱、圆二色光谱(CD)和粘度测定等方法研究了该配合物与小牛胸腺DNA(CT-DNA)的相互作用.结果表明,配合物以插入方式与CT-DNA结合.光谱法研究该配合物与牛血清白蛋白(BSA)的相互作用表明,它主要以静态猝灭方式使BSA的内源性荧光发生猝灭,可引起蛋白构象的变化.计算得到了其结合常数Kb和结合位点数n.展开更多
基金National Natural Science Foundation of China(Grant No.21271012)
文摘Vanadium compounds are promising anti-diabetic agents. However, the concern in the toxicity, especially the long-term renal side effect along with diabetic status, is restricting the further development of this metal drug. Recently, we have prepared a bis（（5-hydroxy-4-oxo-4H-pyran-2-yl） methyl 2-hydroxy-benzoatato） oxovanadium（BSOV）, which exhibited excellent hypoglycemic effect with low acute toxicity. In order to facilitate the development of anti-diabetic vanadium complexes, especially BSOV, we studied the long-term toxicity and hypoglycemic effect of BSOV in comparison with bis（maltolato） oxovanadium（BMOV） on both non-diabetic and type II diabetic mice. The experiments confirmed a stable hypoglycemic effect for both the vanadium complexes over the testing period（6–7 months）. However, the chronic administration of vanadium compounds slightly increased oxidative stress in ICR mice and the induced renal interstitial edema（RIE） in a part of the diabetic animals associated with low levels of serum albumin. The use of an antioxidant dietary supplement（a combination of vitamin C and Zinc gluconate） could prevent vanadium-induced oxidative stress but have marginal effect on RIE. However, BSOV caused much lower incidence of RIE than BMOV did, suggesting that BSOV is an important step towards the successful development of anti-diabetic vanadium drugs.
基金supported by the Key Program of the Baoji University of Arts and Sciences (No. ZK1018)
文摘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.
基金Project supported by the National Natural Science Foundation of China （No. 20171011 ）.Acknowledgements We are grateful to the endemic disease institute of Jilin University for helping to assay the lowering glucose activity of the complexes.
文摘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.
基金Project supported by the National Natural Science Foundation of China (No. 20171011).
文摘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.
文摘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.
文摘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.
文摘New series of oxovanadium (IV) complexes isolated from 2,4,6-tris-(2-pyridyl)-1,3,5-triazine (L<sup>1</sup>) are incorporated and portrayed using spectroscopic (IR, UV-Vis, ESR, mass spectrometric), magnetic moment, thermal and cyclic voltammetry measurements. The results demonstrate that L<sup>1</sup> acts in various styles of chelation with [V<sub>3</sub>O<sub>3</sub>(L<sup>1</sup>)(SO<sub>4</sub>)<sub>3</sub>(EtOH)<sub>1/2</sub>(H<sub>2</sub>O)<sub>3/2</sub>] 1), [VO(L<sup>1</sup>)(2,4-pentadionate)]·Cl·4HCl 2), [V<sub>2</sub>O<sub>2</sub>(L<sup>1</sup>)(SO<sub>4</sub>)<sub>2</sub>(EtOH)<sub>5/2</sub>] 3), [V<sub>2</sub>O<sub>2</sub>(L<sup>1</sup>)(SO<sub>4</sub>)<sub>2</sub>(EtOH)<sub>3/2</sub>(H<sub>2</sub>O)<sub>1/2</sub>] 4), [VO(L<sup>1</sup>)SO<sub>4</sub> (H<sub>2</sub>O)<sub>3/2</sub>]·2.5H<sub>2</sub>O 5) and [V<sub>2</sub>O<sub>2</sub>(L<sup>1</sup>)(SO<sub>4</sub>)<sub>2</sub>(H<sub>2</sub>O)]·H<sub>2</sub>O 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(L<sup>1</sup>) (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(L<sup>1</sup>)SO<sub>4</sub>(H<sub>2</sub>O)<sub>3/2</sub>]·2.5 H<sub>2</sub>O and [VO(L<sup>1</sup>)(2,4-pentadionate)] Cl·4HCl complexes display the highest powerful activity between all of the investigated complexes.
文摘VPO polymer β NH 4(VO 2)(HPO 4) was synthesized from the mixture of NH 4VO 3 and NH 4H 2PO 4 in aqueous acidic solution. This hydrogenphosphate vanadate crystallizes in the orthorhombic space group Pbca with a=0.680 60(8) nm, b=0.925 70(5) nm, c=1.773 70(2) nm, V=1.117 5(3) nm 3, Z=8, D c=1.743 g·cm -3 , μ=88.54 cm -1 and R=0.051. The structure is built up from VO 5 square pyramid linked by trans vertices through the bridged oxygen atom to form an one dimensional isolated chain of {VO 2HPO 4} n- nunning along the a axis.
文摘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.
文摘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
文摘By using different organic ligands, two 3D inorganic-organic hybrid compounds Co（C4H4N2）（VO3）2 1 and Co（C12H12N2）（VO3）2 2 were synthesized by hydrothermal reaction and characterized by X-ray crystallography. Crystal data： 1. crystal system orthorhombic, space group Pnna, a=1 0.188（2） A, b=1 1.497（2） A, c=7.3975（15） A, V=866.5（3） A^3, Z=4, Dcalcd= 2.705 g/cm^3; 2. crystal system triclinic, space group P1^- （No. 2）, a=8.3190（17） A, b=8.4764（17） A, c=1 1.183（2） A, a=95.48（3）°, β=92.03（3）°, γ=107.24（3）°,V=748.0（3） A^3, Z=2, Dcalcd= 1.958 g/cm^3. The framework of compound 1 contains both {Co（C4H4N2）} and infinite metavanadate chains. Crystal structure of compound 2 is constructed with inorganic {CoV2O6} layers across-linked by organic 1,2-bis（4-pyridyl） ethane ligands. The two compounds are thermally stable to approximately 410 ℃ and 350 ℃, respectively. Their optical band gaps are determined to be 2.13 eV and 2.12 eV by UV-VIS-NIR diffuse reflectance spectra, which revealed their nature of semiconductor and optical absorption features.
文摘合成了一种新的L-天冬酰胺邻香草醛席夫碱和1,10-邻菲咯啉的氧钒配合物[VO(o-Van-L-Asn)(Phen)]1.5CH3OH(o-Van-L-Asn=邻香草醛与L-天冬酰胺形成的席夫碱,Phen=1,10-邻菲咯啉).利用红外光谱对其进行了表征,并通过X射线单晶衍射测定了其晶体结构.该晶体属于三斜晶系,P-1空间群,晶胞参数为:a=0.98990(10)nm,b=1.21591(11)nm,c=1.28349(12)nm,α=66.8180(10)°,β=83.816(2)o,γ=66.4150(10)o,V=1.2992(2)nm3,Dc=1.430 g cm-3,Z=1,F(000)=580,R1=0.0626,wR2=0.1631.通过紫外吸收光谱、荧光光谱、圆二色光谱(CD)和粘度测定等方法研究了该配合物与小牛胸腺DNA(CT-DNA)的相互作用.结果表明,配合物以插入方式与CT-DNA结合.光谱法研究该配合物与牛血清白蛋白(BSA)的相互作用表明,它主要以静态猝灭方式使BSA的内源性荧光发生猝灭,可引起蛋白构象的变化.计算得到了其结合常数Kb和结合位点数n.
