A selective and sensitive reagent of 2-pyridine carboxaldehyde isonicotinyl hydrazone（2-PYAINH） was synthesized and studied for the spectrophotometric determination of nickel, copper, cobalt, and iron in detail. At ...A selective and sensitive reagent of 2-pyridine carboxaldehyde isonicotinyl hydrazone（2-PYAINH） was synthesized and studied for the spectrophotometric determination of nickel, copper, cobalt, and iron in detail. At a pH value of 7.0, 9,0, 9.0, and 8.0, respectively, which greatly increased the selectivity; nickel, copper, cobalt, and iron reacted with 2-PYAINH to form a 1：2 yellow-orange, 1：2 yellow-green, 1：2 yellow and 1：1 yellow complexes, with absorption peaks at 363, 352, 346, and 359 nm, respectively. Under the optimal conditions, Beer＇s law was obeyed over the ranges of 0.01-1.4, 0.01-1.5, 0.01-2.7, and 0.01-5.4 mg/L respectively. The apparent molar absorptivity and Sandell＇s sensitivities were 8.4×10^4, 5.2×10^4, 7.1×10^4, and 3.9×10^4 L·mol^-l·cm^-1, respectively, and 0.00069, 0.0012, 0.00078, and 0.0014 μg·cm2, respectively. The detection limits were found to be 0.001, 0.002, 0.003, and 0.01 mg/L, respectively. The detailed study of various interfering ions to make the method more sensitive was carried out and selective and several real samples were analyzed with satisfactory results.展开更多
A new metal-organic coordination polymer [Ni[（2-pya）2（4,4′-bipy）]n·6nH2O （2-pya = 2-pyridinecarboxylic acid, 4,4′-bipy = 4,4′-pyridine） 1 has been hydrothermally synthesized and structurally characterize...A new metal-organic coordination polymer [Ni[（2-pya）2（4,4′-bipy）]n·6nH2O （2-pya = 2-pyridinecarboxylic acid, 4,4′-bipy = 4,4′-pyridine） 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 I4 1/α with a = b = 22.5642（19）, c = 10.7118（18） A, V = 5453.8（11） A^3, C22H28N4NiO10, Mr= 567.19, Dc = 1.382 g/cm^3, μ（MoKα） = 0.769 mm^-1, F（000） =2368, Z = 8, the final R = 0.0572 and wR = 0.1254 for 1401 observed reflections （I 〉 2σ（I））. It exhibits a one-dimensional chain-like structure by mixed ligands of 2-pyridinedicarboxylic acid and 4,4′-pyridine.展开更多
The ligand azobis(2-pyridine) L was used in the synthesis of two new organic-inorganic coordination complexes: [Ni(L)2(NCS)2] 1 and [Co(L)2(NCS)2] 2. Crystal data for 1: monoclinic, space group C2/c, a = 13.361(18), b...The ligand azobis(2-pyridine) L was used in the synthesis of two new organic-inorganic coordination complexes: [Ni(L)2(NCS)2] 1 and [Co(L)2(NCS)2] 2. Crystal data for 1: monoclinic, space group C2/c, a = 13.361(18), b = 10.731(15), c = 18.14(2) ? β = 109.86(2)? V = 2446(6) 3, Z = 4, Mr = 543.25, Dc = 1.410 g/cm3, μ = 0.993 mm-1, F(000) = 1064, T = 298(2) K, R = 0.0454 and wR = 0.1010 for 1288 observed reflections with I > 2s(I); and those for 2: monoclinic, space group C2/c, a = 13.35(2), b = 10.806(15), c = 18.06(2) , β = 110.34(2)? Z = 4, Mr = 543.49, Dc = 1.413 g/cm3, μ = 0.902 mm-1, F(000) = 1060, T = 298(2) K, R = 0.0699 and wR = 0.1354 for 728 observed reflections with I > 2s(I). Single-crystal X-ray diffraction studies revealed that 1 and 2 have similar structures, in which each Ni(II) or Co(II) cation is coordinated by two L ligands and two terminal thiocynates (NCS-).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
The title compounds（PySe）2 1（HPySe=2-pyridineselenol N-oxide,（PySe）2= bis（2-pyridine-N-oxide） diselenide） and Bi2（PySe）6 2 were prepared by the reaction of 2-bromine-N-oxide with NaHSe and Bi（NO3）3·5H...The title compounds（PySe）2 1（HPySe=2-pyridineselenol N-oxide,（PySe）2= bis（2-pyridine-N-oxide） diselenide） and Bi2（PySe）6 2 were prepared by the reaction of 2-bromine-N-oxide with NaHSe and Bi（NO3）3·5H2O with HPySe,and the crystal structure of 2 was studied.Compound 2 crystallizes in the monoclinic space group P21/n with a=9.840（2）,b=10.204（2）,c=18.395（2）,β=102.926（2）°,V=1800.0（5）3,Dc=2.2687 g/cm3,Z=2,the final R=0.0319 and wR=0.0646.The Bi atoms are coordinated by four selenium and four oxygen atoms from four PySe ligands to form a slightly distorted four-column geometry.展开更多
A kinetic study is reported here on hydrolysis of three pyridinecarboxamides in high-temperature water in the temperature range of 190-250℃ at 8 MPa. 2-Pyridinecarboxamide, 3-pyridinecarboxamide and 4-pyridinecarboxa...A kinetic study is reported here on hydrolysis of three pyridinecarboxamides in high-temperature water in the temperature range of 190-250℃ at 8 MPa. 2-Pyridinecarboxamide, 3-pyridinecarboxamide and 4-pyridinecarboxamide hydrolyze to corresponding picolinic acids. 2-Picolinic acid is further decarboxylated to pyridine. Experiments at different temperatures show that the first-order rate constants display an Arrhenius behavior with activation energies of （110.9 ±2.3）, （70.4 ± 2.1） and （61.4 ± 1.8）kJ.mo1-1 for 2- pyridinecarboxamide, 3-pyridinecarboxamide and 4-pyridinecarboxamide, respectively. These kinetic parameters for pyridinecarboxamide hydrolysis are more reliable and accurate than those from the consecutive hydrolysis of cyanopyridines.展开更多
文摘A selective and sensitive reagent of 2-pyridine carboxaldehyde isonicotinyl hydrazone（2-PYAINH） was synthesized and studied for the spectrophotometric determination of nickel, copper, cobalt, and iron in detail. At a pH value of 7.0, 9,0, 9.0, and 8.0, respectively, which greatly increased the selectivity; nickel, copper, cobalt, and iron reacted with 2-PYAINH to form a 1：2 yellow-orange, 1：2 yellow-green, 1：2 yellow and 1：1 yellow complexes, with absorption peaks at 363, 352, 346, and 359 nm, respectively. Under the optimal conditions, Beer＇s law was obeyed over the ranges of 0.01-1.4, 0.01-1.5, 0.01-2.7, and 0.01-5.4 mg/L respectively. The apparent molar absorptivity and Sandell＇s sensitivities were 8.4×10^4, 5.2×10^4, 7.1×10^4, and 3.9×10^4 L·mol^-l·cm^-1, respectively, and 0.00069, 0.0012, 0.00078, and 0.0014 μg·cm2, respectively. The detection limits were found to be 0.001, 0.002, 0.003, and 0.01 mg/L, respectively. The detailed study of various interfering ions to make the method more sensitive was carried out and selective and several real samples were analyzed with satisfactory results.
基金Supported by the Science and Technology Research Projects of the Education Office of Jilin Province (No. 2007. 213)
文摘A new metal-organic coordination polymer [Ni[（2-pya）2（4,4′-bipy）]n·6nH2O （2-pya = 2-pyridinecarboxylic acid, 4,4′-bipy = 4,4′-pyridine） 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 I4 1/α with a = b = 22.5642（19）, c = 10.7118（18） A, V = 5453.8（11） A^3, C22H28N4NiO10, Mr= 567.19, Dc = 1.382 g/cm^3, μ（MoKα） = 0.769 mm^-1, F（000） =2368, Z = 8, the final R = 0.0572 and wR = 0.1254 for 1401 observed reflections （I 〉 2σ（I））. It exhibits a one-dimensional chain-like structure by mixed ligands of 2-pyridinedicarboxylic acid and 4,4′-pyridine.
基金NNSFC (No 20361004)and NSF of Yunnan Province (No 2003E0012M and2003RC13) and Yunnan University (No 2002Z001GC)
文摘The ligand azobis(2-pyridine) L was used in the synthesis of two new organic-inorganic coordination complexes: [Ni(L)2(NCS)2] 1 and [Co(L)2(NCS)2] 2. Crystal data for 1: monoclinic, space group C2/c, a = 13.361(18), b = 10.731(15), c = 18.14(2) ? β = 109.86(2)? V = 2446(6) 3, Z = 4, Mr = 543.25, Dc = 1.410 g/cm3, μ = 0.993 mm-1, F(000) = 1064, T = 298(2) K, R = 0.0454 and wR = 0.1010 for 1288 observed reflections with I > 2s(I); and those for 2: monoclinic, space group C2/c, a = 13.35(2), b = 10.806(15), c = 18.06(2) , β = 110.34(2)? Z = 4, Mr = 543.49, Dc = 1.413 g/cm3, μ = 0.902 mm-1, F(000) = 1060, T = 298(2) K, R = 0.0699 and wR = 0.1354 for 728 observed reflections with I > 2s(I). Single-crystal X-ray diffraction studies revealed that 1 and 2 have similar structures, in which each Ni(II) or Co(II) cation is coordinated by two L ligands and two terminal thiocynates (NCS-).
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 the Natural Science Foundation of Xuzhou city government (Nos XJ07069 and XJ08069)
文摘The title compounds（PySe）2 1（HPySe=2-pyridineselenol N-oxide,（PySe）2= bis（2-pyridine-N-oxide） diselenide） and Bi2（PySe）6 2 were prepared by the reaction of 2-bromine-N-oxide with NaHSe and Bi（NO3）3·5H2O with HPySe,and the crystal structure of 2 was studied.Compound 2 crystallizes in the monoclinic space group P21/n with a=9.840（2）,b=10.204（2）,c=18.395（2）,β=102.926（2）°,V=1800.0（5）3,Dc=2.2687 g/cm3,Z=2,the final R=0.0319 and wR=0.0646.The Bi atoms are coordinated by four selenium and four oxygen atoms from four PySe ligands to form a slightly distorted four-column geometry.
基金Supported by the National Natural Science Foundation of China(21176218)Zhejiang Key Innovation Team of Green Pharmaceutical Technology(2010R50043)
文摘A kinetic study is reported here on hydrolysis of three pyridinecarboxamides in high-temperature water in the temperature range of 190-250℃ at 8 MPa. 2-Pyridinecarboxamide, 3-pyridinecarboxamide and 4-pyridinecarboxamide hydrolyze to corresponding picolinic acids. 2-Picolinic acid is further decarboxylated to pyridine. Experiments at different temperatures show that the first-order rate constants display an Arrhenius behavior with activation energies of （110.9 ±2.3）, （70.4 ± 2.1） and （61.4 ± 1.8）kJ.mo1-1 for 2- pyridinecarboxamide, 3-pyridinecarboxamide and 4-pyridinecarboxamide, respectively. These kinetic parameters for pyridinecarboxamide hydrolysis are more reliable and accurate than those from the consecutive hydrolysis of cyanopyridines.
