Two hydrazone ligands (E)-N'-(2-hydroxy-5-methoxybenzylidene)-2-hydroxybenzo- hydrazide (HLa) and (E)-N'-(3,5-dichloro-2- hydroxybenzylidene)-4-methoxybenzohydrazide (HLb) were prepared and characterized...Two hydrazone ligands (E)-N'-(2-hydroxy-5-methoxybenzylidene)-2-hydroxybenzo- hydrazide (HLa) and (E)-N'-(3,5-dichloro-2- hydroxybenzylidene)-4-methoxybenzohydrazide (HLb) were prepared and characterized by IR, UV-Vis and 1H NMR spectra. Based on the hydrazone ligands, two new structurally similar vanadium(V) complexes, [VOLaL].CH3OH (1) and [vOLbL] (2), where L is the monoanionic form of benzohydroxamic acid (HL), were prepared and characterized by IR and UV-Vis spectra, and single-crystal X-ray diffraction. Complex 1 crystallizes as the monoclinic space group P21/n, with a = 7.5208(10), b = 15.490(2), c = 20.8929(18) A, β = 96.373(2)°, V = 2418.9(5) A3, Z = 4, R = 0.0831, wR = 0.2607 and GOOF = 1.061. Complex 2 crystallizes as the monoclinic space group P21/c, with a = 11.8577(18), b = 16.468(2), c = 12.2288(18) A, β = 106.064(2)°, V= 2294.7(6) A3, Z = 4, R= 0.0741, wR= 0.1745 and GOOF= 1.014. X-ray analysis indicates that the complexes are mononuclear vanadium (V) species, with the V atoms located in the octahedral coordination. The hydrazone ligands and the complexes were evaluated for their antibacterial (Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas fluorescence) and antifungal (Candida albicans and Aspergillus niger) activities by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) method.展开更多
A novel imidazole-functionalized dioxovanadium complex [V2O2(C2O4)(aIM)4] (aIM =1-allylimidazole) was synthesized by the reaction of VO(acac)2 with 1-allylimidazole and fully characterized by single-crystal X-...A novel imidazole-functionalized dioxovanadium complex [V2O2(C2O4)(aIM)4] (aIM =1-allylimidazole) was synthesized by the reaction of VO(acac)2 with 1-allylimidazole and fully characterized by single-crystal X-ray diffraction (SCXRD),powder X-ray diffraction (PXRD),X-ray photoelectron spectroscopy (XPS),Fourier transform infrared spectroscopy (FT-IR) and elemental analyses.Interestingly,the oxalate was in-situ generated from the acetylacetone anion of VO(acac)2 and further coordinated with the vanadium cation and finally complex 1 was achieved.The crystal of complex 1 belongs to the monoclinic system,space group P21/n with a =10.7922(9),b =10.6296(8),c =13.2936(11) (A),μ =0.677 mm^-1,Mr =686.48,V =1516.9(2) A^3,Z =2,Dc =1.503 g/cm^3,F(000) =708,R =0.0543,and wR =0.1517 for 2459 observed reflections with Ⅰ 〉 2σ(Ⅰ).Notably,complex 1 is further used as catalyst in the oxidation of sulfides using H2O2 as the oxidant and exhibits excellent catalytic performance (conv.up to 95.6%,sele.up to 98.9%).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
The liquid-phase direct catalytic amination of benzene to aniline was performed in acetic acid water solvent using a series of vanadium (Ⅲ, Ⅳ,Ⅴ) complexes with N,O- or O,O-ligands as catalysts and hydroxylamine h...The liquid-phase direct catalytic amination of benzene to aniline was performed in acetic acid water solvent using a series of vanadium (Ⅲ, Ⅳ,Ⅴ) complexes with N,O- or O,O-ligands as catalysts and hydroxylamine hydrochloride as the aminating agent. The vanadium complexes exhibited much higher selectivity towards the production of aniline than NaVO3 or VOSO4. Under the optimized conditions, an aniline yield of 42.5% and a TON of 48 with a high selectivity of above 99.9% was obtained using 0.2 mmol of [VO(OAc)2] as the catalyst.展开更多
The mononuclear vanadium(V) complex with 2-hydroxyl-l-naphthaldehyde isonicotinoyl hydrazone was synthesized and characterized by single-crystal X-ray diffraction. The crystal is of monocfinic, space group P2 1/n wi...The mononuclear vanadium(V) complex with 2-hydroxyl-l-naphthaldehyde isonicotinoyl hydrazone was synthesized and characterized by single-crystal X-ray diffraction. The crystal is of monocfinic, space group P2 1/n with α = 10.3153(15), b = 7.4024(11 ), c = 24.413(4) A, β = 101.911(2)°, V= 1824.0(5) A^3, Z= 4, Mr = 427.28, Dc = 1.556 g/cm^3, F(000) = 880,μ(MoKα) = 0.591, the final R = 0.0372 and wR = 0.0926. The vanadium(V) atom adopts a distorted square-pyramidal geometry coordinated by the tridentate ligand and two oxygen atoms. The hydrogen bonds and strong π-π stacking interactions link the complex molecules into a 3-D network structure.展开更多
Two oxo-vanadium(IV) complexes, [VO(C2O4)(2,2′-bipy)(H2O)]·C2H5OH(1) and VO(C2O4)(phen)(H2O) (2), where 2,2′-bipy=2,2′-bipyridyl, phen=1,10-phenanthroline, were synthesized as potential funct...Two oxo-vanadium(IV) complexes, [VO(C2O4)(2,2′-bipy)(H2O)]·C2H5OH(1) and VO(C2O4)(phen)(H2O) (2), where 2,2′-bipy=2,2′-bipyridyl, phen=1,10-phenanthroline, were synthesized as potential functional models of vanadium haloperoxidases(VHPOs) in mixed solvent of ethanol and water at room temperature. The complexes were characterized by elemental analysis, infrared(IR), UV-Vis and X-ray crystallography. Structural analyses showed that vanadium atom was coordinated by a terminal oxygen, one oxygen atom from coordinated water, two oxygen atoms from the carboxylate group of oxalic acid, and two nitrogen atoms(N1 and N2) from 2,2′-bipy/phen. Central vanadium atoms in complexes 1 and 2 were both in a distorted-octahedral environment, and some intermolecular hydrogen bonding linkages were also observed in each complex. Bromination reaction activity of the two complexes was evaluated with phenol red as organic substrate in the presence of H2O2, Br-and phosphate buffer, indicating that they can be considered as a potential functional model of VHPO. In addition, thermal analysis was also performed and discussed in detail.展开更多
Two novel VO(IV) Schiff base complexes, VO(SALHA)2[SALHA: salicyaldehyde- oxyammonia] and VO(o-VANHA)2 [o-VANHA: o-vanillin-oxyammonia], have been synthesized with salicyaldehyde or o-vanilline, hydroxylammonium chlor...Two novel VO(IV) Schiff base complexes, VO(SALHA)2[SALHA: salicyaldehyde- oxyammonia] and VO(o-VANHA)2 [o-VANHA: o-vanillin-oxyammonia], have been synthesized with salicyaldehyde or o-vanilline, hydroxylammonium chloride and vanadyl sulfate in absolute methanol, and their crystal structures were determined by single-crystal X-ray diffraction. The vanadium(IV) centers in both complexes are five-coordinate in a distorted square pyramidal geometry. VO(SALHA)2 (C14H12N2O5V, Mr = 339.20) crystallizes in the monoclinic system, space group P21/n with a = 14.716(9), b = 7.175(5), c = 14.716(9) ? b = 113.130(7), V = 1428.8(15) 3, Z = 4, Dc = 1.577 g/cm3, l = 0.71073 ? m(MoKa) = 0.720 mm-1, F(000) = 692, the final R = 0.0466 and wR = 0.0829 for 1561 observed reflections (I > 2s(I)). VO(o-VANHA)2 (C16H16N2O7V, Mr = 399.25) is of monoclinic, space group P21/n with a = 11.386(12), b = 10.405(10), c = 14.627(15) , b = 93.654(19), V = 1729(3) 3, Z = 4, Dc = 1.533 g/cm3, l = 0.71073 , m(MoKa) = 0.615 mm-1, F(000) = 820, the final R = 0.0513 and wR = 0.1129 for 1235 observed reflections (I > 2s(I)).展开更多
A new complexes of Cp2Ti[S2P(OR)2]2 (where R = Et, Pr-n, Pr-i, Bu-i and Ph) and Cp2Ti[S2POGO]2 (where G = -CH2CMe2CH2-, -CH2CEt2CH2- and -CMe2CMe2-) were prepared by the dropwise addition of the appropriate O,O’-dial...A new complexes of Cp2Ti[S2P(OR)2]2 (where R = Et, Pr-n, Pr-i, Bu-i and Ph) and Cp2Ti[S2POGO]2 (where G = -CH2CMe2CH2-, -CH2CEt2CH2- and -CMe2CMe2-) were prepared by the dropwise addition of the appropriate O,O’-dialkyl or -alkylenedithiophosphoric acid to biscyclopentadienyl titanium dichloride in 1:2 molar ratio and refluxed in benzene solution. These novel deep red colored complexes were characterized by elemental analyses, molecular weight measurements and spectroscopic techniques (IR., NMR 1H, 13C and 31P NMR). These titanium (IV) dithio complexes have also been screened for their antibacterial activities.展开更多
The new oxovanadium(V)complex,[PyH][VO2(L)]1(salicyladehyde 5-bromo salicyloylhydrazone is abbreviated as H2L;Hpy is protonated pyridine)was obtained from a refluxed solution of VOSO4 and H2L in acetonitrile-methanol-...The new oxovanadium(V)complex,[PyH][VO2(L)]1(salicyladehyde 5-bromo salicyloylhydrazone is abbreviated as H2L;Hpy is protonated pyridine)was obtained from a refluxed solution of VOSO4 and H2L in acetonitrile-methanol-pyridine.Similarly,another new complex,[VO(L)(OCH3)]2 was synthesized by refluxing VOSO4 and H2L in methanol-pyridine.Crystal data for 1:C19H15N3O5BrV,Mr=496.2,monoclinic,P21/n,a=7.1885(3),b=9.2718(3),c=28.803(1)A,β=96.185(1)°,Z=4and V=1908.6(1)A^3;for 2:C15H12N2O5BrV,Mr=431.1,monoclinic ,P21/n,a=12.202(2),b=8.045(2),c=16.604(3)A,β=101.29(3)°,Z=4 and V=1598.4(2)A^3.The structures of 1 and 2 have been determined by X-ray analyses and reveal that the coordination environments of V atoms in both complexes are of square-based pyramid.Three of the four based donor atoms are from the tridentate“ONO”donor ligand while the fourth is one terminal oxygen atom with the V(1)-O(3)distance 1.646(4)Afor 1 and one-OCH3 group with the V(1)-O(3) distance 1.753(3)Afor 2.The V(1)-O(4) terminals occupy the axial sites in both cases.The complexes are also characterized by IR and ^1HNMR spectroscopies.展开更多
High-yielding low-cost vanadium oxide nanotubes were prepared by the hydrothermal self-assembling process from vanadium pentoxide and organic molecules as structure-directing templates.Moreover,a new method was discov...High-yielding low-cost vanadium oxide nanotubes were prepared by the hydrothermal self-assembling process from vanadium pentoxide and organic molecules as structure-directing templates.Moreover,a new method was discovered for determining the content of V (IV) in vanadium oxide nanotubes by thermogravimetric analysis (TGA).This method is simple,precise and feasible and can be extended to determine the content of low oxidation state in the other transition metal oxide nanomaterials.展开更多
Divanadium(Ⅴ) complex [VO(aptch)(μ-OCH3)]2(1) and two monovanadium(Ⅴ) complexes [VO(apfah))(OEt)](2a and 2b,H2aptch = 2-hydroxyacetophenone thiophene-2-car-boxylic hydrazone,H2apfah = 2-hydroxyaceto...Divanadium(Ⅴ) complex [VO(aptch)(μ-OCH3)]2(1) and two monovanadium(Ⅴ) complexes [VO(apfah))(OEt)](2a and 2b,H2aptch = 2-hydroxyacetophenone thiophene-2-car-boxylic hydrazone,H2apfah = 2-hydroxyacetophenone 2-furoic acid hydrazone) have been synthesized and characterized.Single-crystal X-ray diffraction studies reveal that 1 is a cen-trosymmetric dimer bridged by two methoxido O-atoms.Complex 1 crystallizes in the monoclinic crystal system,space groups P21/c with a = 7.4825(4),b = 17.0928(11),c = 11.6961(7) ,β = 98.172(4)o,Z = 2,F(000) = 728,μ = 0.829 mm-1,the final R = 0.0457 and wR = 0.1137 for 2654 observed reflections with I 〉 2(I).The vanadium(V) is coordinated to the tridentate ligand,ethanol molecule to form a distorted square-pyramidal geometry,complexes 2a and 2b.Although 2a and 2b have the same asymmetric unit,they belong to different space groups.Complex 2a crystallizes in the monoclinic crystal system,space groups P21/n with a = 10.2293(2),b = 15.6660(3),c = 10.6298(2) ,β = 116.259(1)o,Z = 4,μ = 0.676 mm-1;complex 2b crystallizes in the triclinic crystal system,space groups P with a = 8.2808(4),b = 9.4704(5),c = 10.0819(5) ,α = 86.133(3),= 81.956(3),γ = 80.248(3)o,Z = 2 and μ = 0.670 mm-1.The hydrogen bonds are found to exist in 2b only.The crystal structure is stabilized by intermolecular hydrogen bonds of C-H···O.展开更多
A novel vanadium(V) oxoperoxo complex [VOO2(APTCH)(CH3OH)] (HAPTCH = 2-acetylpyridine thiophene-2-carboxylic hydrazone) has been synthesized and characterized by IR, TGA and X-ray single-crystal structure dete...A novel vanadium(V) oxoperoxo complex [VOO2(APTCH)(CH3OH)] (HAPTCH = 2-acetylpyridine thiophene-2-carboxylic hydrazone) has been synthesized and characterized by IR, TGA and X-ray single-crystal structure determination. The complex crystallizes in the monoclinic system, space group P21/c with a = 11.232(2), b = 10.762(2), c = 112.613(3), β = 99.44(3)°, V = 1504.1(5)3, Dc = 1.657 g·cm-3, Z = 4, F(000) = 768, μ = 0.827 mm-1, the final R = 0.0392 and wR = 0.1073 for 2266 observed reflections with I 〉 2σ(I). Single-crystal X-ray diffraction studies reveal that the vanadium(V) is coordinated by a tridentate ligand, methanol molecule and peroxo group to form a pentagonal-bipyramidal geometry. The crystal structure is stabilized by intermolecular hydrogen bonds of O-H···N and C-H···O.展开更多
Five new organotin(IV) complexes of ortho-vanillin-2-hydrazinopyridine hydrazone with formula [RnSnCl4–n(VHP)] [R = Me2, n = 2 (2);R = Ph2, n = 2 (3);R= nBu2, n = 2 (4);R = nBu, n = 2 (5) and R = 1, n = 0 (6)] have b...Five new organotin(IV) complexes of ortho-vanillin-2-hydrazinopyridine hydrazone with formula [RnSnCl4–n(VHP)] [R = Me2, n = 2 (2);R = Ph2, n = 2 (3);R= nBu2, n = 2 (4);R = nBu, n = 2 (5) and R = 1, n = 0 (6)] have been synthesized by direct reaction of ortho-vanillin-2-hydrazinopyridine hydrazone [(VHP), (1)], base and organotin(IV) chloride(s) in absolute methanol. The hydrazone ligand [(VHP), (1)] and its organotin(IV) complexes (2-6) have been characterized by UV-Visible, FT-IR and 1H NMR spectral studies. Spectroscopic data suggested that in the complexes (2-4), the ligand (1) acted as a neutral bidentate ligand and is coordinated to the tin(IV) atom via the azomethine nitrogen and pyridyl nitrogen atoms, whereas the ligand (1) acted as a uninegative tridentate ligand and coordinated to the tin(IV) atom through phenolic-O, azomethine-N and pyridyl-N atoms in complexes (5-6). The toxicity of the ligand (1) and its organotin (IV) complexes (2-6) were determined against Artemia salina. Organotin(IV) complexes showed moderate activity against Artemia salina. The ligand (1) and its organotin(IV) complexes (2-6) were also tested against four types of bacteria namely Bacillus cereus, Staphylococcus aureus, Escherichia coli and Enterobacter aerogenes. All organotin(IV) complexes and the free ligand (1) showed better antibacterial activities against bacteria. Among the organotin(IV) complexes (2-6), diphenyltin(IV) complex (3) showed higher activity against the four types of bacteria.展开更多
New dibutyltin(IV) complexes of Schiff base derived from 5-chloroindoline-2,3-dione, indoline- 2,3-dione with amino acids (tryptophan, alanine and valine) were synthesized and characterized by elemental analysis, IR, ...New dibutyltin(IV) complexes of Schiff base derived from 5-chloroindoline-2,3-dione, indoline- 2,3-dione with amino acids (tryptophan, alanine and valine) were synthesized and characterized by elemental analysis, IR, electronic spectra, conductance measurements, and biological activity. The analytical data showed that the Schiff base ligand acts as bidentate towards metal ions via the azomethine nitrogen and carboxylate oxygen by a stoichiometric reaction of M:L (1:2) to form metal complexes. NMR (1H, 13C and 119Sn) spectral data of the ligands and metal complex agree with proposed structures. The conductivity values between 14 - 27 ohm-1cm2mol-1 in DMF imply the presence of non-electrolyte species. 3D molecular modeling and analysis of bond lengths and bond angles have also been conducted for a representative compound, [Bu2Sn(L2)2], to substantiate the proposed structures. Antibacterial results indicate that the metal complexes are more active than the free ligands.展开更多
Two vanadium complexes of schiff base vith rich phenolate oxygen,o-(?)-salicylideneamino- methylphenol,had been synthesized and characterized.One is a V(Ⅳ)complex with an interaction via vanadyl oxygen and the other ...Two vanadium complexes of schiff base vith rich phenolate oxygen,o-(?)-salicylideneamino- methylphenol,had been synthesized and characterized.One is a V(Ⅳ)complex with an interaction via vanadyl oxygen and the other is a novel dinuclear V(V,V)complex with an oxo bridge.The conversion between the two complexes had been discussed.展开更多
A new heteronuclear complex, dimer [(2-OH2)2Ba2(H2O)4][VO2(tpa)]24H2O (tpa: 2,4,6-tripicolinate trianion), was synthesized and structurally determined by X-ray diffraction technique where all hydrogen atoms have been ...A new heteronuclear complex, dimer [(2-OH2)2Ba2(H2O)4][VO2(tpa)]24H2O (tpa: 2,4,6-tripicolinate trianion), was synthesized and structurally determined by X-ray diffraction technique where all hydrogen atoms have been located directly. The coordination geometry of V(V) ion is a distorted trigonal bipyrimid and that of Ba(II) ion is a capped square antiprism. One 2-O bridging bond and two hydrogen bonds act between the coordination geometries. A 1-D extended porous construction containing 20-member cavities is observed in the crystal.展开更多
基金the Educational Commission of Henan Province (No. 14B150036)the Natural Science Foundation of Henan Province (No. 142300410252)the Key Disciplines of Analytical Chemistry of Henan Province
文摘Two hydrazone ligands (E)-N'-(2-hydroxy-5-methoxybenzylidene)-2-hydroxybenzo- hydrazide (HLa) and (E)-N'-(3,5-dichloro-2- hydroxybenzylidene)-4-methoxybenzohydrazide (HLb) were prepared and characterized by IR, UV-Vis and 1H NMR spectra. Based on the hydrazone ligands, two new structurally similar vanadium(V) complexes, [VOLaL].CH3OH (1) and [vOLbL] (2), where L is the monoanionic form of benzohydroxamic acid (HL), were prepared and characterized by IR and UV-Vis spectra, and single-crystal X-ray diffraction. Complex 1 crystallizes as the monoclinic space group P21/n, with a = 7.5208(10), b = 15.490(2), c = 20.8929(18) A, β = 96.373(2)°, V = 2418.9(5) A3, Z = 4, R = 0.0831, wR = 0.2607 and GOOF = 1.061. Complex 2 crystallizes as the monoclinic space group P21/c, with a = 11.8577(18), b = 16.468(2), c = 12.2288(18) A, β = 106.064(2)°, V= 2294.7(6) A3, Z = 4, R= 0.0741, wR= 0.1745 and GOOF= 1.014. X-ray analysis indicates that the complexes are mononuclear vanadium (V) species, with the V atoms located in the octahedral coordination. The hydrazone ligands and the complexes were evaluated for their antibacterial (Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas fluorescence) and antifungal (Candida albicans and Aspergillus niger) activities by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) method.
基金supported by the NNSFC(No.21401094)Project of Shandong Province Higher Educational Science and Technology Program(No.J16LC53)+1 种基金Science and the Technology Development Plans of Liaocheng(No.2014GJH01)the National College Students'Science and Technology Innovation Fund(No.1420800)
文摘A novel imidazole-functionalized dioxovanadium complex [V2O2(C2O4)(aIM)4] (aIM =1-allylimidazole) was synthesized by the reaction of VO(acac)2 with 1-allylimidazole and fully characterized by single-crystal X-ray diffraction (SCXRD),powder X-ray diffraction (PXRD),X-ray photoelectron spectroscopy (XPS),Fourier transform infrared spectroscopy (FT-IR) and elemental analyses.Interestingly,the oxalate was in-situ generated from the acetylacetone anion of VO(acac)2 and further coordinated with the vanadium cation and finally complex 1 was achieved.The crystal of complex 1 belongs to the monoclinic system,space group P21/n with a =10.7922(9),b =10.6296(8),c =13.2936(11) (A),μ =0.677 mm^-1,Mr =686.48,V =1516.9(2) A^3,Z =2,Dc =1.503 g/cm^3,F(000) =708,R =0.0543,and wR =0.1517 for 2459 observed reflections with Ⅰ 〉 2σ(Ⅰ).Notably,complex 1 is further used as catalyst in the oxidation of sulfides using H2O2 as the oxidant and exhibits excellent catalytic performance (conv.up to 95.6%,sele.up to 98.9%).
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.
基金supported by the National Natural Science Foundation of China(No.200720024).
文摘The liquid-phase direct catalytic amination of benzene to aniline was performed in acetic acid water solvent using a series of vanadium (Ⅲ, Ⅳ,Ⅴ) complexes with N,O- or O,O-ligands as catalysts and hydroxylamine hydrochloride as the aminating agent. The vanadium complexes exhibited much higher selectivity towards the production of aniline than NaVO3 or VOSO4. Under the optimized conditions, an aniline yield of 42.5% and a TON of 48 with a high selectivity of above 99.9% was obtained using 0.2 mmol of [VO(OAc)2] as the catalyst.
基金Supported by the Science Foundation of Guangxi Province (No. 0342025), the Youth Science Foundation of Guangxi Province (No. 0542020) and the Teaching and Research Award Programme for Outstanding Young Teachers in Higher Education Institutions of MOE, China
文摘The mononuclear vanadium(V) complex with 2-hydroxyl-l-naphthaldehyde isonicotinoyl hydrazone was synthesized and characterized by single-crystal X-ray diffraction. The crystal is of monocfinic, space group P2 1/n with α = 10.3153(15), b = 7.4024(11 ), c = 24.413(4) A, β = 101.911(2)°, V= 1824.0(5) A^3, Z= 4, Mr = 427.28, Dc = 1.556 g/cm^3, F(000) = 880,μ(MoKα) = 0.591, the final R = 0.0372 and wR = 0.0926. The vanadium(V) atom adopts a distorted square-pyramidal geometry coordinated by the tridentate ligand and two oxygen atoms. The hydrogen bonds and strong π-π stacking interactions link the complex molecules into a 3-D network structure.
基金Supported by the National Natural Science Foundation of China(No.21071071)the Education Foundation of Dalian City in China(No.2009J21DW004)
文摘Two oxo-vanadium(IV) complexes, [VO(C2O4)(2,2′-bipy)(H2O)]·C2H5OH(1) and VO(C2O4)(phen)(H2O) (2), where 2,2′-bipy=2,2′-bipyridyl, phen=1,10-phenanthroline, were synthesized as potential functional models of vanadium haloperoxidases(VHPOs) in mixed solvent of ethanol and water at room temperature. The complexes were characterized by elemental analysis, infrared(IR), UV-Vis and X-ray crystallography. Structural analyses showed that vanadium atom was coordinated by a terminal oxygen, one oxygen atom from coordinated water, two oxygen atoms from the carboxylate group of oxalic acid, and two nitrogen atoms(N1 and N2) from 2,2′-bipy/phen. Central vanadium atoms in complexes 1 and 2 were both in a distorted-octahedral environment, and some intermolecular hydrogen bonding linkages were also observed in each complex. Bromination reaction activity of the two complexes was evaluated with phenol red as organic substrate in the presence of H2O2, Br-and phosphate buffer, indicating that they can be considered as a potential functional model of VHPO. In addition, thermal analysis was also performed and discussed in detail.
基金The work was supported by the Science Foundation of Liaocheng University
文摘Two novel VO(IV) Schiff base complexes, VO(SALHA)2[SALHA: salicyaldehyde- oxyammonia] and VO(o-VANHA)2 [o-VANHA: o-vanillin-oxyammonia], have been synthesized with salicyaldehyde or o-vanilline, hydroxylammonium chloride and vanadyl sulfate in absolute methanol, and their crystal structures were determined by single-crystal X-ray diffraction. The vanadium(IV) centers in both complexes are five-coordinate in a distorted square pyramidal geometry. VO(SALHA)2 (C14H12N2O5V, Mr = 339.20) crystallizes in the monoclinic system, space group P21/n with a = 14.716(9), b = 7.175(5), c = 14.716(9) ? b = 113.130(7), V = 1428.8(15) 3, Z = 4, Dc = 1.577 g/cm3, l = 0.71073 ? m(MoKa) = 0.720 mm-1, F(000) = 692, the final R = 0.0466 and wR = 0.0829 for 1561 observed reflections (I > 2s(I)). VO(o-VANHA)2 (C16H16N2O7V, Mr = 399.25) is of monoclinic, space group P21/n with a = 11.386(12), b = 10.405(10), c = 14.627(15) , b = 93.654(19), V = 1729(3) 3, Z = 4, Dc = 1.533 g/cm3, l = 0.71073 , m(MoKa) = 0.615 mm-1, F(000) = 820, the final R = 0.0513 and wR = 0.1129 for 1235 observed reflections (I > 2s(I)).
文摘A new complexes of Cp2Ti[S2P(OR)2]2 (where R = Et, Pr-n, Pr-i, Bu-i and Ph) and Cp2Ti[S2POGO]2 (where G = -CH2CMe2CH2-, -CH2CEt2CH2- and -CMe2CMe2-) were prepared by the dropwise addition of the appropriate O,O’-dialkyl or -alkylenedithiophosphoric acid to biscyclopentadienyl titanium dichloride in 1:2 molar ratio and refluxed in benzene solution. These novel deep red colored complexes were characterized by elemental analyses, molecular weight measurements and spectroscopic techniques (IR., NMR 1H, 13C and 31P NMR). These titanium (IV) dithio complexes have also been screened for their antibacterial activities.
基金The work was supported by the Chinese Academy of Sciences, the National Natural Science Foundation of China(20073048)the NSF of Fujian province for financial support
文摘The new oxovanadium(V)complex,[PyH][VO2(L)]1(salicyladehyde 5-bromo salicyloylhydrazone is abbreviated as H2L;Hpy is protonated pyridine)was obtained from a refluxed solution of VOSO4 and H2L in acetonitrile-methanol-pyridine.Similarly,another new complex,[VO(L)(OCH3)]2 was synthesized by refluxing VOSO4 and H2L in methanol-pyridine.Crystal data for 1:C19H15N3O5BrV,Mr=496.2,monoclinic,P21/n,a=7.1885(3),b=9.2718(3),c=28.803(1)A,β=96.185(1)°,Z=4and V=1908.6(1)A^3;for 2:C15H12N2O5BrV,Mr=431.1,monoclinic ,P21/n,a=12.202(2),b=8.045(2),c=16.604(3)A,β=101.29(3)°,Z=4 and V=1598.4(2)A^3.The structures of 1 and 2 have been determined by X-ray analyses and reveal that the coordination environments of V atoms in both complexes are of square-based pyramid.Three of the four based donor atoms are from the tridentate“ONO”donor ligand while the fourth is one terminal oxygen atom with the V(1)-O(3)distance 1.646(4)Afor 1 and one-OCH3 group with the V(1)-O(3) distance 1.753(3)Afor 2.The V(1)-O(4) terminals occupy the axial sites in both cases.The complexes are also characterized by IR and ^1HNMR spectroscopies.
文摘High-yielding low-cost vanadium oxide nanotubes were prepared by the hydrothermal self-assembling process from vanadium pentoxide and organic molecules as structure-directing templates.Moreover,a new method was discovered for determining the content of V (IV) in vanadium oxide nanotubes by thermogravimetric analysis (TGA).This method is simple,precise and feasible and can be extended to determine the content of low oxidation state in the other transition metal oxide nanomaterials.
基金supported by the Scientific Research Common Program of Beijing Municipal Commission of Education,PRC (KM200910028011)
文摘Divanadium(Ⅴ) complex [VO(aptch)(μ-OCH3)]2(1) and two monovanadium(Ⅴ) complexes [VO(apfah))(OEt)](2a and 2b,H2aptch = 2-hydroxyacetophenone thiophene-2-car-boxylic hydrazone,H2apfah = 2-hydroxyacetophenone 2-furoic acid hydrazone) have been synthesized and characterized.Single-crystal X-ray diffraction studies reveal that 1 is a cen-trosymmetric dimer bridged by two methoxido O-atoms.Complex 1 crystallizes in the monoclinic crystal system,space groups P21/c with a = 7.4825(4),b = 17.0928(11),c = 11.6961(7) ,β = 98.172(4)o,Z = 2,F(000) = 728,μ = 0.829 mm-1,the final R = 0.0457 and wR = 0.1137 for 2654 observed reflections with I 〉 2(I).The vanadium(V) is coordinated to the tridentate ligand,ethanol molecule to form a distorted square-pyramidal geometry,complexes 2a and 2b.Although 2a and 2b have the same asymmetric unit,they belong to different space groups.Complex 2a crystallizes in the monoclinic crystal system,space groups P21/n with a = 10.2293(2),b = 15.6660(3),c = 10.6298(2) ,β = 116.259(1)o,Z = 4,μ = 0.676 mm-1;complex 2b crystallizes in the triclinic crystal system,space groups P with a = 8.2808(4),b = 9.4704(5),c = 10.0819(5) ,α = 86.133(3),= 81.956(3),γ = 80.248(3)o,Z = 2 and μ = 0.670 mm-1.The hydrogen bonds are found to exist in 2b only.The crystal structure is stabilized by intermolecular hydrogen bonds of C-H···O.
基金supported by the Scientific Research Common Program of Beijing Municipal Commission of Education, PRC (KM200910028011)
文摘A novel vanadium(V) oxoperoxo complex [VOO2(APTCH)(CH3OH)] (HAPTCH = 2-acetylpyridine thiophene-2-carboxylic hydrazone) has been synthesized and characterized by IR, TGA and X-ray single-crystal structure determination. The complex crystallizes in the monoclinic system, space group P21/c with a = 11.232(2), b = 10.762(2), c = 112.613(3), β = 99.44(3)°, V = 1504.1(5)3, Dc = 1.657 g·cm-3, Z = 4, F(000) = 768, μ = 0.827 mm-1, the final R = 0.0392 and wR = 0.1073 for 2266 observed reflections with I 〉 2σ(I). Single-crystal X-ray diffraction studies reveal that the vanadium(V) is coordinated by a tridentate ligand, methanol molecule and peroxo group to form a pentagonal-bipyramidal geometry. The crystal structure is stabilized by intermolecular hydrogen bonds of O-H···N and C-H···O.
文摘Five new organotin(IV) complexes of ortho-vanillin-2-hydrazinopyridine hydrazone with formula [RnSnCl4–n(VHP)] [R = Me2, n = 2 (2);R = Ph2, n = 2 (3);R= nBu2, n = 2 (4);R = nBu, n = 2 (5) and R = 1, n = 0 (6)] have been synthesized by direct reaction of ortho-vanillin-2-hydrazinopyridine hydrazone [(VHP), (1)], base and organotin(IV) chloride(s) in absolute methanol. The hydrazone ligand [(VHP), (1)] and its organotin(IV) complexes (2-6) have been characterized by UV-Visible, FT-IR and 1H NMR spectral studies. Spectroscopic data suggested that in the complexes (2-4), the ligand (1) acted as a neutral bidentate ligand and is coordinated to the tin(IV) atom via the azomethine nitrogen and pyridyl nitrogen atoms, whereas the ligand (1) acted as a uninegative tridentate ligand and coordinated to the tin(IV) atom through phenolic-O, azomethine-N and pyridyl-N atoms in complexes (5-6). The toxicity of the ligand (1) and its organotin (IV) complexes (2-6) were determined against Artemia salina. Organotin(IV) complexes showed moderate activity against Artemia salina. The ligand (1) and its organotin(IV) complexes (2-6) were also tested against four types of bacteria namely Bacillus cereus, Staphylococcus aureus, Escherichia coli and Enterobacter aerogenes. All organotin(IV) complexes and the free ligand (1) showed better antibacterial activities against bacteria. Among the organotin(IV) complexes (2-6), diphenyltin(IV) complex (3) showed higher activity against the four types of bacteria.
文摘New dibutyltin(IV) complexes of Schiff base derived from 5-chloroindoline-2,3-dione, indoline- 2,3-dione with amino acids (tryptophan, alanine and valine) were synthesized and characterized by elemental analysis, IR, electronic spectra, conductance measurements, and biological activity. The analytical data showed that the Schiff base ligand acts as bidentate towards metal ions via the azomethine nitrogen and carboxylate oxygen by a stoichiometric reaction of M:L (1:2) to form metal complexes. NMR (1H, 13C and 119Sn) spectral data of the ligands and metal complex agree with proposed structures. The conductivity values between 14 - 27 ohm-1cm2mol-1 in DMF imply the presence of non-electrolyte species. 3D molecular modeling and analysis of bond lengths and bond angles have also been conducted for a representative compound, [Bu2Sn(L2)2], to substantiate the proposed structures. Antibacterial results indicate that the metal complexes are more active than the free ligands.
文摘Two vanadium complexes of schiff base vith rich phenolate oxygen,o-(?)-salicylideneamino- methylphenol,had been synthesized and characterized.One is a V(Ⅳ)complex with an interaction via vanadyl oxygen and the other is a novel dinuclear V(V,V)complex with an oxo bridge.The conversion between the two complexes had been discussed.
基金This project is supported by NNSF of China(60172003)Specialized Research Foundations of Shandong Province(11120106).
文摘A new heteronuclear complex, dimer [(2-OH2)2Ba2(H2O)4][VO2(tpa)]24H2O (tpa: 2,4,6-tripicolinate trianion), was synthesized and structurally determined by X-ray diffraction technique where all hydrogen atoms have been located directly. The coordination geometry of V(V) ion is a distorted trigonal bipyrimid and that of Ba(II) ion is a capped square antiprism. One 2-O bridging bond and two hydrogen bonds act between the coordination geometries. A 1-D extended porous construction containing 20-member cavities is observed in the crystal.