This study presents the synthesis of three dinuclear cobalt complexes based on three imine derivatives:bis-[4-(2-pyridylmethyleneamino)-phenyl]thioether(L1),bis-[4-(2-pyridylmethyleneamino)-phenyl]ether(L2),and bis-[4...This study presents the synthesis of three dinuclear cobalt complexes based on three imine derivatives:bis-[4-(2-pyridylmethyleneamino)-phenyl]thioether(L1),bis-[4-(2-pyridylmethyleneamino)-phenyl]ether(L2),and bis-[4-(2-pyridylmethyleneamino)-phenyl]methane(L3).Single-crystal X-ray diffraction analysis reveals that the complexes[Co_(2)(L1)3](ClO_(4))4·2CH_(3)CN(1),[Co_(2)(L2)3](ClO_(4))4·2CH_(3)OH(2),and[Co_(2)(L3)3](ClO_(4))4·2CH_(3)OH(3)all exhibit a dinuclear structure.Magnetic test results show that complex 3 exhibited irreversible SCO behavior induced by loss of solvent at 300 K,with the average Co-N bond length increasing from 0.2139(3)to 0.2153(3)nm.Meanwhile,the desolvated complex 3 exhibited paramagnetic behavior similar to that of complexes 1 and 2.Variable-temperature UV-Vis spectroscopic studies also indicate that complex 3 undergoes a solvent-loss-induced spin-state transition.CCDC:2347354,1(120 K);2347355,2(120 K);2347356,3(120 K);2347357,3(400 K).展开更多
Two cobalt(Ⅱ) complexes 1 and 2 of Schiff bases derived from amino acids were synthesized and used for oxidation of benzyl alcohol with molecular oxygen at different conditions of pH,solvent,temperature and complex...Two cobalt(Ⅱ) complexes 1 and 2 of Schiff bases derived from amino acids were synthesized and used for oxidation of benzyl alcohol with molecular oxygen at different conditions of pH,solvent,temperature and complex/alcohol molar ratio to optimize reaction conditions and to evaluate the catalytic efficiency of new cobalt Schiff base complexes.Under obtained optimum conditions,various alcohols were oxidized to corresponding aldehydes and ketones.展开更多
The title nickel complex I and cobalt complex II were obtained separately from the direct reaction of D-(+)-leucinol with Ni(II) chloride and L-(-)-leucinol with Co(II) acetate tetra- hydrate in anhydrous met...The title nickel complex I and cobalt complex II were obtained separately from the direct reaction of D-(+)-leucinol with Ni(II) chloride and L-(-)-leucinol with Co(II) acetate tetra- hydrate in anhydrous methanol. The crystal structures of I and II were determined by single-crystal X-ray diffraction and further characterized by elemental analysis and IR. For I: [Ni(C18H45N3O3)]Cl2, orthorhombic, P212121, a = 11.2807(9), b = 14.7115(11), c = 16.3580(13) A, V = 2714.7(4) A3, Z = 4, Pcalcd = 1.177 Mg/m3, the final R = 0.0407, and 16539 reflections observed with I 〉 2σ(/); For II: [Co(C45HI08N6015)], trigonal, R3:H, a = 23.981(3), b =23.981(3), c = 10.8925(15) A, γ = 120°, V = 5425.1(14) A3, Z = 3, Pcalcd = 1.002 Mg/m3, the final R = 0.0625 for 16556 observed reflections with I 〉 2σ(I). The complexes were then used to catalyze the Henry reaction and obtained good catalytic results. The catalytic activity of the complexes was determined by IH NMR. And research is going towards the application to other organic reactions such as cyanosilylation reaction.展开更多
A novel cobalt complex,[Co2(bptc)(bix)1.5](1,H4bptc=3,3',4,4'-biphenyltetra-carboxylic acid,bix = 1,4-bis(imidazol-1-ylmethyl)benzene),has been hydrothermally prepared and characterized by IR spectroscopy,el...A novel cobalt complex,[Co2(bptc)(bix)1.5](1,H4bptc=3,3',4,4'-biphenyltetra-carboxylic acid,bix = 1,4-bis(imidazol-1-ylmethyl)benzene),has been hydrothermally prepared and characterized by IR spectroscopy,elemental analysis and single-crystal X-ray diffraction.The crystal is of triclinic system,space group P1 with a=10.770(7),b=12.245(8),c=13.514(9),α=102.829(8),β=107.734(8),γ=98.833(9)°,C37H27N6O8Co2,Mr=801.51,V=1607.5(18)3,Dc=1.656g/cm3,F(000)=818,μ=1.100mm-1,Z=2,the final R = 0.0694 and wR = 0.1543 for 3034 observed reflections(I2σ(I)).In the title complex,the two Co(Ⅱ) ions are in different coordination environments with distorted octahedral and trigonal bipyramidal geometries,respectively.The Co atoms are linked together through hexadentate bptc ligands,giving rise to 2D layers which are bridged by the bix ligands into a 3-D supramolecular network.Magnetic susceptibilities of 1 reveal weak antiferromagnetic exchange interactions between the adjacent Co(Ⅱ) ions.展开更多
Two new metal-organic complexes,{[Co2(bptc)(DPPZ)2(H2O)2]·H2O}n 1 and {[Co2(ccm)2(DPPZ)2]·2H2O}n 2,were obtained by the hydrothermal reactions of Co(NO3)2·6H2O with chelating ligand dipyrido...Two new metal-organic complexes,{[Co2(bptc)(DPPZ)2(H2O)2]·H2O}n 1 and {[Co2(ccm)2(DPPZ)2]·2H2O}n 2,were obtained by the hydrothermal reactions of Co(NO3)2·6H2O with chelating ligand dipyrido[3,2-a:2',3'-c]phenazine(DPPZ) and the corresponding carboxylic acid,namely,3,3',4,4'-benzophenonetetracarboxylic acid(H4bptc) or 2-carboxycinnamic acid(H2ccm),respectively.The complexes were structurally characterized by single-crystal X-ray diffraction,elemental analyses,IR spectra,and thermal gravimetry.1 presents unique chiral chain structures,which are further consolidated into three-dimensional supramolecular frameworks via noncovalent bonds,such as hydrogen bonding and π-π interactions.2 features infinite double-chain structures,which are connected by strong π-π interactions to result in three-dimensional supramolecular architectures.展开更多
Two new Co(Ⅱ) coordination polymers,{[Co_3(Hchda)_2(chda)_2(bpp)_2(H_2O)_2]}_n 1 and {[Co(chda)(bpe)(H_2O)]·3H_2O}_n 2(H_2chda = 1,1-cyclohexanediacetic acid,bpp = 1,3-bis(4-pyridinyl)propane ...Two new Co(Ⅱ) coordination polymers,{[Co_3(Hchda)_2(chda)_2(bpp)_2(H_2O)_2]}_n 1 and {[Co(chda)(bpe)(H_2O)]·3H_2O}_n 2(H_2chda = 1,1-cyclohexanediacetic acid,bpp = 1,3-bis(4-pyridinyl)propane and bpe = 1,2-bis(4-pyridinyl)ethylene),were hydrothermally synthesized and then characterized by elemental analysis,IR spectroscopy,thermogravimetric analysis(TGA),and single-crystal X-ray diffraction.Complex 1 possesses an infinite metal-organic layer based on triply bridged linear trinuclear subunits and complex 2 exhibits a square(4,4) grid layer with dangling lateral arms resulting from eight-membered rings above and below the layer.In addition,magnetic properties of complexes 1 and 2 are also given.展开更多
A new cobalt(II) complex [Co(NO2-salen)2]·1.5H2O containing mono acetalization Schiff base ligand(NO2-salen = N-5-nitro-salicylideneamino ethanato) has been prepared through one-pot template condensation, a...A new cobalt(II) complex [Co(NO2-salen)2]·1.5H2O containing mono acetalization Schiff base ligand(NO2-salen = N-5-nitro-salicylideneamino ethanato) has been prepared through one-pot template condensation, and has been structurally characterized by elemental analysis, IR spectra and X-ray diffraction. It is formulated as C18H23CoN6O7.5, crystallizes in the hexagonal system, space group of R-3c with α = 25.895(18), b = 25.895(18), c = 35.075(6), γ = 120o, V = 20368(3) and Z = 36. The ligand of 5-nitrosalicylaldehyde-ethylene-diamine takes unusual mono asymmetry mode. The Co(II) ion exhibits a coordination number of six, and assumes a distorted octahedral geometry with a N2O4 donor set. The neutral monomeric units of [Co(NO2-salen)2]·1.5H2O are linked into a one-dimensional(1D) structure via the intermolecular hydrogen bonds and weak π-π stacking interactions. Cyclic-voltammetry measurement reveals the oxidation and reduction processes for the complex are irreversible in nature.展开更多
A new metal-organic complex Co2(cbba)4(phen)2(μ2-OH2)(H2cbba=2-(4'-chlorine-benzoyl)benzoic acid,phen=1,10-phenanthroline) 1 has been hydrothermally synthesized and struc-turally characterized by single-cr...A new metal-organic complex Co2(cbba)4(phen)2(μ2-OH2)(H2cbba=2-(4'-chlorine-benzoyl)benzoic acid,phen=1,10-phenanthroline) 1 has been hydrothermally synthesized and struc-turally characterized by single-crystal X-ray diffraction,elemental analyses,TG and IR spectroscopy.The compound crystallizes in triclinic,space group P1 with a=10.7659(7),b=17.1856(11),c=19.2022(13),α=83.8120(10),β=84.9930(10),γ=87.2070(10)°,V=3515.8(4)3,C80H50Cl4Co2N4O13,Mr=1534.90,Dc=1.450 g/cm3,μ(MoKα)=0.693 mm-1,F(000)=1568,Z=2,the final R=0.0490 and wR=0.1092 for 8216 observed reflections(Ⅰ 〉2σ(Ⅰ)).In the crystal structure,the cobalt atom is six-coordinated with three carboxylate oxygen atoms from three different cbba ligands,one oxygen atom from coordinated water molecule and two nitrogen atoms from phen ligand,showing a distorted octahedral geometry.Furthermore,it exhibits a 3D supramolecular network through π-π and hydrogen bonding interactions.展开更多
A new metal-organic coordination polymer [Co(2-pya)2(4,4'-bipy)]2n-[(4,4'- bipy)0.5· H2O]2n (2-pya = 2-pyridinecarboxylic acid, 4,4'-bipy = 4,4'-bipyridine) 1 has been hydrothermally synthesized and s...A new metal-organic coordination polymer [Co(2-pya)2(4,4'-bipy)]2n-[(4,4'- bipy)0.5· H2O]2n (2-pya = 2-pyridinecarboxylic acid, 4,4'-bipy = 4,4'-bipyridine) 1 has been hydrothermally synthesized and structurally characterized by elemental analysis, IR spectrum, TG and single-crystal X-ray diffraction. The complex crystallizes in tetragonal, space group I41/a with a = b = 22.719(2), c = 10.710(2)/k, V = 5527.8(14) A3, C54H46N10Co2O10, Mr= 1112.87, Dc = 1.337 g/cm3,μ(MoKa) = 0.665 mm-1, F(000) = 2296, Z = 4, the final R = 0.0633 and wR = 0.1096 for 1261 observed reflections (I 〉 2σ(I)). It exhibits a one-dimensional chain-like structure constructed by mixed ligands of 2-pyridinedicarboxylic acid and 4,4'-bipyridine.展开更多
One complex [Co1.5(C6H5CHCHCOO)3(Medpq)]·H2O(C6H5CHCHCOO = cinnamic acid, Medpq = 2-methyldipyrido[3,2-f:2,3-h]quinoxaline) 1 has been hydrothermally synthesized and structurally characterized by elemental...One complex [Co1.5(C6H5CHCHCOO)3(Medpq)]·H2O(C6H5CHCHCOO = cinnamic acid, Medpq = 2-methyldipyrido[3,2-f:2,3-h]quinoxaline) 1 has been hydrothermally synthesized and structurally characterized by elemental analysis, IR spectrum, TG, single-crystal X-ray diffraction and magnetic susceptibility measurements. Complex 1 crystallizes in the triclinic system, space group P1, with a = 10.224(5), b = 14.572(5), c = 15.139(5)A, α = 112.704(5), β = 97.168(5), γ = 109.749(5), V = 1871.8(13) 3 and Z = 2(at 293(2) K). In the crystal structure, the Co(1) ion is hexa-coordinated with six atoms from three different cinnamic acid ligands and the symmetric three different cinnamic acid ligands; the Co(2) center adopts a coordination environment with two nitrogen atoms from Medpq ligand and four oxygen atoms from two different cinnamic ligands, assuming a slightly distorted octahedral geometry, respectively. The negative value of the Weiss constant indicates antiferromagnetic exchange interactions between the Co ions.展开更多
Two complexes with a zwitterionic dicarboxylate ligand,Mn(L)2(H2O)4 1 and Co(L)2(H2O)4 2(L = 1-carboxymethylpyridinium-4-carboxylate),were synthesized and structurally characterized.Complex 1 crystallizes in...Two complexes with a zwitterionic dicarboxylate ligand,Mn(L)2(H2O)4 1 and Co(L)2(H2O)4 2(L = 1-carboxymethylpyridinium-4-carboxylate),were synthesized and structurally characterized.Complex 1 crystallizes in monoclinic,space group P21 with a = 6.490(2),b = 19.210(7),c = 7.813(3) ,β = 92.716(5)o,V = 972.9(6) 3,Z = 2,Mr = 487.28,Dc = 1.663 g/cm3,F(000) = 502,μ = 0.749 mm-1,S = 1.060,the final R = 0.0377 and wR = 0.0893 for 3292 observed reflections with I 2σ(I).Complex 2 is isomorphous with 1,with a = 6.478(2),b = 19.052(7),c = 7.742(3) ,β = 92.690(4)o,V = 954.6(6) 3,Z = 2,Mr = 491.28,Dc = 1.709 g/cm3,F(000) = 506,μ = 0.971 mm-1,S = 1.035,the final R = 0.0425 and wR = 0.0809 for 3289 observed reflections with I 2σ(I).In the compounds,the mononuclear [M(L)2(H2O)4] units with trans-octahedral coordination geometry are linked into 3D architectures via hydrogen bonding(or second-sphere coordination) involving carboxylate groups and coordinated water molecules.The 3D networks illustrate a 3,8-connected net with Schlfli symbol(4·62)2(42·623·83).展开更多
Two new cobalt(Ⅱ)complexes[Co2(2,2?-bipy)2(dpa)2(H2O)5]·4H2O(1)and Co(2,2?-bipy)3(SO4)]·7.5H2O(2)have been synthesized with diaphonic acid(H2dpa)and 2,2?-bipyridine(2,2?-bipy)as ligands....Two new cobalt(Ⅱ)complexes[Co2(2,2?-bipy)2(dpa)2(H2O)5]·4H2O(1)and Co(2,2?-bipy)3(SO4)]·7.5H2O(2)have been synthesized with diaphonic acid(H2dpa)and 2,2?-bipyridine(2,2?-bipy)as ligands.In 1,two neighboring cobalt(Ⅱ)ions are linked together by one bridging diaphonic acid group,forming an asymmetric dinuclear structure.1 crystallizes in triclinic,space group ■ with a=9.825(6),b=13.007(8),c=19.586(1)?,α=80.773(1)o,β=77.065(1)o,γ=85.902(1)o,Mr=431.4,V=2406.5(3)?3,Dc=1.48 g/cm3,Z=2,μ(MoKα)=0.767 mm-1,F(000)=1112,the final R=0.0379 and wR=0.0862.The central cobalt(Ⅱ)ions in 1 and 2 are coordinated with six atoms,forming distorted octahedral coordination geometry.The fluorescence and thermal stability properties of 1 and 2 are also reported.展开更多
A novel dinuclear complex with an empirical formula [Co2(1H-benzimidazole)4(1, 4-bdoa)2] (1,4-bdoa2– = benzene-1,4-dioxyacetate dianion) has been synthesized and characterized by elemental analysis, IR and single-cry...A novel dinuclear complex with an empirical formula [Co2(1H-benzimidazole)4(1, 4-bdoa)2] (1,4-bdoa2– = benzene-1,4-dioxyacetate dianion) has been synthesized and characterized by elemental analysis, IR and single-crystal X-ray diffraction. It crystallizes in monoclinic system, space group P21/c with a = 11.000(2), b = 19.385(4), c = 11.417(2) ?, β = 95.49(3)o, V = 2423.3(8) ?3, Z = 2, Mr = 1074.77, Dc = 1.473 g/cm3, μ = 0.760 mm–1, F(000) = 1108, the final R = 0.0645 and wR = 0.0714 for 3273 observed reflections (I > 2σ(I)). Two octahedrally coordinated Co(II) atoms are bridged by two 1,4-bdoa2– groups, generating a macrocyclic ring complex. The Co…Co separa- tion is 7.677(3) ?. An extended 3-D supramolecular network is formed through hydrogen bonds and weak π-π stacking interactions.展开更多
The complete experimental IR spectra and vibrational analysis of the title complex Co(mnt)(dmbpy) were reported in this paper. The results show that the complex molecule has a planar geometry belonging to point group ...The complete experimental IR spectra and vibrational analysis of the title complex Co(mnt)(dmbpy) were reported in this paper. The results show that the complex molecule has a planar geometry belonging to point group C 2v and ground electronic state with spin quartet. A new method for analyzing vibrational spectra of complicated molecule is established. The essential of this method is to point out main fixed points and pivotal vibrational units in assignment for each fundamental band. Two new symbols η (heaving along the specified direction) and M (midpoint of a bond or unit) were defined for describing the vibrational modes accurately.展开更多
3-Methoxysalicylaldehyde was condensed with the amines 4-aminoacetophenone and 2-amino-5-bromopyridine to obtain Schiff base ligands, 1 and 2, which were coordinated to cobalt salts as complex 1 and complex 2, respect...3-Methoxysalicylaldehyde was condensed with the amines 4-aminoacetophenone and 2-amino-5-bromopyridine to obtain Schiff base ligands, 1 and 2, which were coordinated to cobalt salts as complex 1 and complex 2, respectively. The synthesized ligands and complexes were characterized by spectroscopic(FT-IR,UV–Vis,~1H-NMR and mass spectrometry), thermal(TGA) and elemental analysis. The structures of the complexes were verified by evaluating their magnetic susceptibility and spectroscopic evidences. Synthesized complexes were studied for their catalytic activity in the Suzuki–Miyaura cross-coupling of aryl halides with phenylboronic acid. Optimized reaction yields 90% of the cyanobiphenyl for complex 1 and 91% for complex 2 with 0.1 mmol of catalyst loading thereby substantiating the C\\C coupling efficiency of the synthesized complexes, 1 and 2.展开更多
Photosynthesis in nature has been deemed as the most significant biochemical reaction,which maintains a relatively stable content of O_(2) and CO_(2) in the atmosphere.Herein,for a deeper comprehension of natural phot...Photosynthesis in nature has been deemed as the most significant biochemical reaction,which maintains a relatively stable content of O_(2) and CO_(2) in the atmosphere.Herein,for a deeper comprehension of natural photosynthesis,an artificial photosynthesis model reaction of photochemical CO_(2) to CO conversion(CO_(2)+2 H^(+)+2e^(-)→CO+H_(2)O)catalyzed by a homogeneous hexanuclear ring cobalt complex{K_(2)[CoO_(3)PCH_(2)N(CH_(2)CO_(2))_(2)]}_(6)(Co6 complex)is developed.Using the[Ru(bpy)_(3)]^(2+)as a photosensitizer and TEOA as a sacrificial electron donor,an optimal turnover frequency of 503.3 h^(‒1) and an apparent quantum efficiency of 0.81%are obtained.The good photocatalytic CO_(2) reduction performance is attributed to the efficient electron transfer between Co6 complex and[Ru(bpy)_(3)]^(2+),which boosts the photogenerated carriers separation of the photosensitizer.It is confirmed by the j‐V curves,light‐assisted UV‐vis curves,steady‐state photoluminescence spectra and real‐time laser flash photolysis experiments.In addition,the proposed catalytic mechanism for CO_(2) reduction reaction catalyzed by the Co6 complex is explored by the potassium thiocyanate poison experiment,Pourbaix diagram and density functional theory calculations.展开更多
文摘This study presents the synthesis of three dinuclear cobalt complexes based on three imine derivatives:bis-[4-(2-pyridylmethyleneamino)-phenyl]thioether(L1),bis-[4-(2-pyridylmethyleneamino)-phenyl]ether(L2),and bis-[4-(2-pyridylmethyleneamino)-phenyl]methane(L3).Single-crystal X-ray diffraction analysis reveals that the complexes[Co_(2)(L1)3](ClO_(4))4·2CH_(3)CN(1),[Co_(2)(L2)3](ClO_(4))4·2CH_(3)OH(2),and[Co_(2)(L3)3](ClO_(4))4·2CH_(3)OH(3)all exhibit a dinuclear structure.Magnetic test results show that complex 3 exhibited irreversible SCO behavior induced by loss of solvent at 300 K,with the average Co-N bond length increasing from 0.2139(3)to 0.2153(3)nm.Meanwhile,the desolvated complex 3 exhibited paramagnetic behavior similar to that of complexes 1 and 2.Variable-temperature UV-Vis spectroscopic studies also indicate that complex 3 undergoes a solvent-loss-induced spin-state transition.CCDC:2347354,1(120 K);2347355,2(120 K);2347356,3(120 K);2347357,3(400 K).
文摘Two cobalt(Ⅱ) complexes 1 and 2 of Schiff bases derived from amino acids were synthesized and used for oxidation of benzyl alcohol with molecular oxygen at different conditions of pH,solvent,temperature and complex/alcohol molar ratio to optimize reaction conditions and to evaluate the catalytic efficiency of new cobalt Schiff base complexes.Under obtained optimum conditions,various alcohols were oxidized to corresponding aldehydes and ketones.
文摘The title nickel complex I and cobalt complex II were obtained separately from the direct reaction of D-(+)-leucinol with Ni(II) chloride and L-(-)-leucinol with Co(II) acetate tetra- hydrate in anhydrous methanol. The crystal structures of I and II were determined by single-crystal X-ray diffraction and further characterized by elemental analysis and IR. For I: [Ni(C18H45N3O3)]Cl2, orthorhombic, P212121, a = 11.2807(9), b = 14.7115(11), c = 16.3580(13) A, V = 2714.7(4) A3, Z = 4, Pcalcd = 1.177 Mg/m3, the final R = 0.0407, and 16539 reflections observed with I 〉 2σ(/); For II: [Co(C45HI08N6015)], trigonal, R3:H, a = 23.981(3), b =23.981(3), c = 10.8925(15) A, γ = 120°, V = 5425.1(14) A3, Z = 3, Pcalcd = 1.002 Mg/m3, the final R = 0.0625 for 16556 observed reflections with I 〉 2σ(I). The complexes were then used to catalyze the Henry reaction and obtained good catalytic results. The catalytic activity of the complexes was determined by IH NMR. And research is going towards the application to other organic reactions such as cyanosilylation reaction.
基金supported by the National Natural Science Foundation of China (No 20971004)the Outstanding Youth Foundation of Education Commission of Anhui Province (No 2010SQRL108ZD)
文摘A novel cobalt complex,[Co2(bptc)(bix)1.5](1,H4bptc=3,3',4,4'-biphenyltetra-carboxylic acid,bix = 1,4-bis(imidazol-1-ylmethyl)benzene),has been hydrothermally prepared and characterized by IR spectroscopy,elemental analysis and single-crystal X-ray diffraction.The crystal is of triclinic system,space group P1 with a=10.770(7),b=12.245(8),c=13.514(9),α=102.829(8),β=107.734(8),γ=98.833(9)°,C37H27N6O8Co2,Mr=801.51,V=1607.5(18)3,Dc=1.656g/cm3,F(000)=818,μ=1.100mm-1,Z=2,the final R = 0.0694 and wR = 0.1543 for 3034 observed reflections(I2σ(I)).In the title complex,the two Co(Ⅱ) ions are in different coordination environments with distorted octahedral and trigonal bipyramidal geometries,respectively.The Co atoms are linked together through hexadentate bptc ligands,giving rise to 2D layers which are bridged by the bix ligands into a 3-D supramolecular network.Magnetic susceptibilities of 1 reveal weak antiferromagnetic exchange interactions between the adjacent Co(Ⅱ) ions.
基金Supported by the National Natural Science Foundation of China (No. 60978059)Program for New Century Excellent Talents in University (NCET-10-0176)the Natural Science Foundation of Jilin Province (No. 20090527)
文摘Two new metal-organic complexes,{[Co2(bptc)(DPPZ)2(H2O)2]·H2O}n 1 and {[Co2(ccm)2(DPPZ)2]·2H2O}n 2,were obtained by the hydrothermal reactions of Co(NO3)2·6H2O with chelating ligand dipyrido[3,2-a:2',3'-c]phenazine(DPPZ) and the corresponding carboxylic acid,namely,3,3',4,4'-benzophenonetetracarboxylic acid(H4bptc) or 2-carboxycinnamic acid(H2ccm),respectively.The complexes were structurally characterized by single-crystal X-ray diffraction,elemental analyses,IR spectra,and thermal gravimetry.1 presents unique chiral chain structures,which are further consolidated into three-dimensional supramolecular frameworks via noncovalent bonds,such as hydrogen bonding and π-π interactions.2 features infinite double-chain structures,which are connected by strong π-π interactions to result in three-dimensional supramolecular architectures.
基金supported by the National Natural Science Foundation of China(No.21571093)the Program for Science&Technology Innovation Talents in Universities of Henan Province(No.14HASTIT017)+1 种基金the Program for Innovative Research Team(in Science and Technology)in University of Henan Province(No.14IRTSTHN008)the Foundation of Education Committee of Henan Province(No.142300410301)
文摘Two new Co(Ⅱ) coordination polymers,{[Co_3(Hchda)_2(chda)_2(bpp)_2(H_2O)_2]}_n 1 and {[Co(chda)(bpe)(H_2O)]·3H_2O}_n 2(H_2chda = 1,1-cyclohexanediacetic acid,bpp = 1,3-bis(4-pyridinyl)propane and bpe = 1,2-bis(4-pyridinyl)ethylene),were hydrothermally synthesized and then characterized by elemental analysis,IR spectroscopy,thermogravimetric analysis(TGA),and single-crystal X-ray diffraction.Complex 1 possesses an infinite metal-organic layer based on triply bridged linear trinuclear subunits and complex 2 exhibits a square(4,4) grid layer with dangling lateral arms resulting from eight-membered rings above and below the layer.In addition,magnetic properties of complexes 1 and 2 are also given.
基金supported by the National Natural Science Foundation of China(No.21273101)the Foundation of the Program for Backbone Teachers in Universities of Henan Province(No.2012GGJS158)+1 种基金tackle key problem of science and technology Project of Henan Province(No.142102310483)the Foundation of Education Committee of Henan Province(No.14B150033)
文摘A new cobalt(II) complex [Co(NO2-salen)2]·1.5H2O containing mono acetalization Schiff base ligand(NO2-salen = N-5-nitro-salicylideneamino ethanato) has been prepared through one-pot template condensation, and has been structurally characterized by elemental analysis, IR spectra and X-ray diffraction. It is formulated as C18H23CoN6O7.5, crystallizes in the hexagonal system, space group of R-3c with α = 25.895(18), b = 25.895(18), c = 35.075(6), γ = 120o, V = 20368(3) and Z = 36. The ligand of 5-nitrosalicylaldehyde-ethylene-diamine takes unusual mono asymmetry mode. The Co(II) ion exhibits a coordination number of six, and assumes a distorted octahedral geometry with a N2O4 donor set. The neutral monomeric units of [Co(NO2-salen)2]·1.5H2O are linked into a one-dimensional(1D) structure via the intermolecular hydrogen bonds and weak π-π stacking interactions. Cyclic-voltammetry measurement reveals the oxidation and reduction processes for the complex are irreversible in nature.
基金supported by the Science and Technology Research Projects of the Education Department of Jilin Province (No. 2009. 272)
文摘A new metal-organic complex Co2(cbba)4(phen)2(μ2-OH2)(H2cbba=2-(4'-chlorine-benzoyl)benzoic acid,phen=1,10-phenanthroline) 1 has been hydrothermally synthesized and struc-turally characterized by single-crystal X-ray diffraction,elemental analyses,TG and IR spectroscopy.The compound crystallizes in triclinic,space group P1 with a=10.7659(7),b=17.1856(11),c=19.2022(13),α=83.8120(10),β=84.9930(10),γ=87.2070(10)°,V=3515.8(4)3,C80H50Cl4Co2N4O13,Mr=1534.90,Dc=1.450 g/cm3,μ(MoKα)=0.693 mm-1,F(000)=1568,Z=2,the final R=0.0490 and wR=0.1092 for 8216 observed reflections(Ⅰ 〉2σ(Ⅰ)).In the crystal structure,the cobalt atom is six-coordinated with three carboxylate oxygen atoms from three different cbba ligands,one oxygen atom from coordinated water molecule and two nitrogen atoms from phen ligand,showing a distorted octahedral geometry.Furthermore,it exhibits a 3D supramolecular network through π-π and hydrogen bonding interactions.
基金supported by Science and Technology Research Projects of the Education Office of Jilin Province (No. 2007. 213)
文摘A new metal-organic coordination polymer [Co(2-pya)2(4,4'-bipy)]2n-[(4,4'- bipy)0.5· H2O]2n (2-pya = 2-pyridinecarboxylic acid, 4,4'-bipy = 4,4'-bipyridine) 1 has been hydrothermally synthesized and structurally characterized by elemental analysis, IR spectrum, TG and single-crystal X-ray diffraction. The complex crystallizes in tetragonal, space group I41/a with a = b = 22.719(2), c = 10.710(2)/k, V = 5527.8(14) A3, C54H46N10Co2O10, Mr= 1112.87, Dc = 1.337 g/cm3,μ(MoKa) = 0.665 mm-1, F(000) = 2296, Z = 4, the final R = 0.0633 and wR = 0.1096 for 1261 observed reflections (I 〉 2σ(I)). It exhibits a one-dimensional chain-like structure constructed by mixed ligands of 2-pyridinedicarboxylic acid and 4,4'-bipyridine.
基金supported by Tonghua Normal University field project(No.201402)
文摘One complex [Co1.5(C6H5CHCHCOO)3(Medpq)]·H2O(C6H5CHCHCOO = cinnamic acid, Medpq = 2-methyldipyrido[3,2-f:2,3-h]quinoxaline) 1 has been hydrothermally synthesized and structurally characterized by elemental analysis, IR spectrum, TG, single-crystal X-ray diffraction and magnetic susceptibility measurements. Complex 1 crystallizes in the triclinic system, space group P1, with a = 10.224(5), b = 14.572(5), c = 15.139(5)A, α = 112.704(5), β = 97.168(5), γ = 109.749(5), V = 1871.8(13) 3 and Z = 2(at 293(2) K). In the crystal structure, the Co(1) ion is hexa-coordinated with six atoms from three different cinnamic acid ligands and the symmetric three different cinnamic acid ligands; the Co(2) center adopts a coordination environment with two nitrogen atoms from Medpq ligand and four oxygen atoms from two different cinnamic ligands, assuming a slightly distorted octahedral geometry, respectively. The negative value of the Weiss constant indicates antiferromagnetic exchange interactions between the Co ions.
基金Supported by NNSFC (20771038)Shanghai Leading Academic Discipline Project (B409)
文摘Two complexes with a zwitterionic dicarboxylate ligand,Mn(L)2(H2O)4 1 and Co(L)2(H2O)4 2(L = 1-carboxymethylpyridinium-4-carboxylate),were synthesized and structurally characterized.Complex 1 crystallizes in monoclinic,space group P21 with a = 6.490(2),b = 19.210(7),c = 7.813(3) ,β = 92.716(5)o,V = 972.9(6) 3,Z = 2,Mr = 487.28,Dc = 1.663 g/cm3,F(000) = 502,μ = 0.749 mm-1,S = 1.060,the final R = 0.0377 and wR = 0.0893 for 3292 observed reflections with I 2σ(I).Complex 2 is isomorphous with 1,with a = 6.478(2),b = 19.052(7),c = 7.742(3) ,β = 92.690(4)o,V = 954.6(6) 3,Z = 2,Mr = 491.28,Dc = 1.709 g/cm3,F(000) = 506,μ = 0.971 mm-1,S = 1.035,the final R = 0.0425 and wR = 0.0809 for 3289 observed reflections with I 2σ(I).In the compounds,the mononuclear [M(L)2(H2O)4] units with trans-octahedral coordination geometry are linked into 3D architectures via hydrogen bonding(or second-sphere coordination) involving carboxylate groups and coordinated water molecules.The 3D networks illustrate a 3,8-connected net with Schlfli symbol(4·62)2(42·623·83).
基金Supported by Hunan Provincial Natural Science Foundation of China(2019JJ60021)the Scientific Research Found of Hunan Provincial Education Department of China(17A049,17C0226)Industry and Research Key Project of Hengyang City(2018KJ016)
文摘Two new cobalt(Ⅱ)complexes[Co2(2,2?-bipy)2(dpa)2(H2O)5]·4H2O(1)and Co(2,2?-bipy)3(SO4)]·7.5H2O(2)have been synthesized with diaphonic acid(H2dpa)and 2,2?-bipyridine(2,2?-bipy)as ligands.In 1,two neighboring cobalt(Ⅱ)ions are linked together by one bridging diaphonic acid group,forming an asymmetric dinuclear structure.1 crystallizes in triclinic,space group ■ with a=9.825(6),b=13.007(8),c=19.586(1)?,α=80.773(1)o,β=77.065(1)o,γ=85.902(1)o,Mr=431.4,V=2406.5(3)?3,Dc=1.48 g/cm3,Z=2,μ(MoKα)=0.767 mm-1,F(000)=1112,the final R=0.0379 and wR=0.0862.The central cobalt(Ⅱ)ions in 1 and 2 are coordinated with six atoms,forming distorted octahedral coordination geometry.The fluorescence and thermal stability properties of 1 and 2 are also reported.
基金This work was supported by the National Natural Science Foundation of China (No. 20101003), Natural Science Foundation of Heilongjiang Province (No. B0007) and the Scientific Fund of Remarkable Teachers of Heilongjiang Province (1054G036)
文摘A novel dinuclear complex with an empirical formula [Co2(1H-benzimidazole)4(1, 4-bdoa)2] (1,4-bdoa2– = benzene-1,4-dioxyacetate dianion) has been synthesized and characterized by elemental analysis, IR and single-crystal X-ray diffraction. It crystallizes in monoclinic system, space group P21/c with a = 11.000(2), b = 19.385(4), c = 11.417(2) ?, β = 95.49(3)o, V = 2423.3(8) ?3, Z = 2, Mr = 1074.77, Dc = 1.473 g/cm3, μ = 0.760 mm–1, F(000) = 1108, the final R = 0.0645 and wR = 0.0714 for 3273 observed reflections (I > 2σ(I)). Two octahedrally coordinated Co(II) atoms are bridged by two 1,4-bdoa2– groups, generating a macrocyclic ring complex. The Co…Co separa- tion is 7.677(3) ?. An extended 3-D supramolecular network is formed through hydrogen bonds and weak π-π stacking interactions.
基金Supported by the National Natural Science F oundation of China( No. 2 97710 2 5 )
文摘The complete experimental IR spectra and vibrational analysis of the title complex Co(mnt)(dmbpy) were reported in this paper. The results show that the complex molecule has a planar geometry belonging to point group C 2v and ground electronic state with spin quartet. A new method for analyzing vibrational spectra of complicated molecule is established. The essential of this method is to point out main fixed points and pivotal vibrational units in assignment for each fundamental band. Two new symbols η (heaving along the specified direction) and M (midpoint of a bond or unit) were defined for describing the vibrational modes accurately.
基金the National Institute of Technology Karnataka for the financial support
文摘3-Methoxysalicylaldehyde was condensed with the amines 4-aminoacetophenone and 2-amino-5-bromopyridine to obtain Schiff base ligands, 1 and 2, which were coordinated to cobalt salts as complex 1 and complex 2, respectively. The synthesized ligands and complexes were characterized by spectroscopic(FT-IR,UV–Vis,~1H-NMR and mass spectrometry), thermal(TGA) and elemental analysis. The structures of the complexes were verified by evaluating their magnetic susceptibility and spectroscopic evidences. Synthesized complexes were studied for their catalytic activity in the Suzuki–Miyaura cross-coupling of aryl halides with phenylboronic acid. Optimized reaction yields 90% of the cyanobiphenyl for complex 1 and 91% for complex 2 with 0.1 mmol of catalyst loading thereby substantiating the C\\C coupling efficiency of the synthesized complexes, 1 and 2.
文摘Photosynthesis in nature has been deemed as the most significant biochemical reaction,which maintains a relatively stable content of O_(2) and CO_(2) in the atmosphere.Herein,for a deeper comprehension of natural photosynthesis,an artificial photosynthesis model reaction of photochemical CO_(2) to CO conversion(CO_(2)+2 H^(+)+2e^(-)→CO+H_(2)O)catalyzed by a homogeneous hexanuclear ring cobalt complex{K_(2)[CoO_(3)PCH_(2)N(CH_(2)CO_(2))_(2)]}_(6)(Co6 complex)is developed.Using the[Ru(bpy)_(3)]^(2+)as a photosensitizer and TEOA as a sacrificial electron donor,an optimal turnover frequency of 503.3 h^(‒1) and an apparent quantum efficiency of 0.81%are obtained.The good photocatalytic CO_(2) reduction performance is attributed to the efficient electron transfer between Co6 complex and[Ru(bpy)_(3)]^(2+),which boosts the photogenerated carriers separation of the photosensitizer.It is confirmed by the j‐V curves,light‐assisted UV‐vis curves,steady‐state photoluminescence spectra and real‐time laser flash photolysis experiments.In addition,the proposed catalytic mechanism for CO_(2) reduction reaction catalyzed by the Co6 complex is explored by the potassium thiocyanate poison experiment,Pourbaix diagram and density functional theory calculations.