Various 4-alkoxypyridine-2, 6-dicarboxylic acids were synthesized starting from 2,6- lutidine.Through aldol condensation and Michael addition, various 4-arylpyridine-2, 6-dicarboxylic acids were synthesized starting f...Various 4-alkoxypyridine-2, 6-dicarboxylic acids were synthesized starting from 2,6- lutidine.Through aldol condensation and Michael addition, various 4-arylpyridine-2, 6-dicarboxylic acids were synthesized starting from aromatic aldehydes and 2-acetylfuran.展开更多
The process of synthesis of dimethyl-2,6-naphthalene dicaboxylate from esterification of 2,6-naphthalene dicarboxylic acid (2,6-NDCA) by methanol using sodium tungstate as catalyst was investigated. The orthogonal tes...The process of synthesis of dimethyl-2,6-naphthalene dicaboxylate from esterification of 2,6-naphthalene dicarboxylic acid (2,6-NDCA) by methanol using sodium tungstate as catalyst was investigated. The orthogonal tests method was used for optimizing the process factors. The effects of reaction temperature, mass percentage of catalyst, reaction time and mass ratio of methanol to 2,6-NDCA on the 2,6-NDCA conversion were investigated. It was found that all the four factors had significant effect on the conversion. The optimum reaction conditions were reaction temperature 215 ℃,mass percentage of catalyst 3%, reaction time 3 h, mass ratio of methanol to 2,6-NDCA 6∶1. The 2,6-NDCA conversion at above condition was 92.80%.展开更多
This paper reports that the low-temperature heat capacities of pyridine-2,6-dicarboxylic acid were measured by a precision automatic calorimeter over a temperature range from 78 K to 380 K.A polynomial equation of hea...This paper reports that the low-temperature heat capacities of pyridine-2,6-dicarboxylic acid were measured by a precision automatic calorimeter over a temperature range from 78 K to 380 K.A polynomial equation of heat capacities as a function of temperature was fitted by the least-squares method.Based on the fitted polynomial,the smoothed heat capacities and thermodynamic functions of the compound relative to the standard reference temperature 298.15 K were calculated and tabulated at intervals of 5 K.The constant-volume energy of combustion of the compound was determined by means of a precision rotating-bomb combustion calorimeter.The standard molar enthalpy of combustion of the compound was derived from the constant-volume energy of combustion.The standard molar enthalpy of formation of the compound was calculated from a combination of the datum of the standard molar enthalpy of combustion of the compound with other auxiliary thermodynamic quantities through a Hess thermochemical cycle.展开更多
A new trinuclear nickel complex,[Ni3(pdc)3(2,2'-bipy)3(H2O)2]·2H2O(H2pdc = pyridine 2,6-dicarboxylic acid,2,2'-bipy = 2,2'-bipyridine) has been hydrothermally synthesized and characterized by IR,eleme...A new trinuclear nickel complex,[Ni3(pdc)3(2,2'-bipy)3(H2O)2]·2H2O(H2pdc = pyridine 2,6-dicarboxylic acid,2,2'-bipy = 2,2'-bipyridine) has been hydrothermally synthesized and characterized by IR,elemental analysis and X-ray diffraction methods.Crystal data for this complex:monoclinic,space group P21/n,a = 21.206(4),b = 10.002(2),c = 28.066(6),β = 108.18(3)°,C51H41N9Ni3O16,Mr = 1212.06,V = 5.656(2) nm3,Dc = 1.423 g·cm-3,μ(MoKα) = 1.062 mm-1,Z = 4,F(000) = 2488,GOOF = 1.034,the final R = 0.0543 and wR = 0.1237 for 6149 observed reflections with Ⅰ > 2σ(Ⅰ).In the complex,three nickel(Ⅱ) ions are bridged by the pyridine 2,6-dicarboxylic acid groups,and all nickel(Ⅱ) ions are seven-coordinated by nitrogen atoms of 2,2'-bipyridine and pyridine 2,6-dicarboxylic acid and oxygen atoms from pyridine 2,6-dicarboxylic and water to adopt a severely distorted pentagonal bipyramidal geometry.The emission and excitation peaks of the complex in ethanol solutions are located at 336 and 316 nm,respectively.展开更多
文摘Various 4-alkoxypyridine-2, 6-dicarboxylic acids were synthesized starting from 2,6- lutidine.Through aldol condensation and Michael addition, various 4-arylpyridine-2, 6-dicarboxylic acids were synthesized starting from aromatic aldehydes and 2-acetylfuran.
文摘The process of synthesis of dimethyl-2,6-naphthalene dicaboxylate from esterification of 2,6-naphthalene dicarboxylic acid (2,6-NDCA) by methanol using sodium tungstate as catalyst was investigated. The orthogonal tests method was used for optimizing the process factors. The effects of reaction temperature, mass percentage of catalyst, reaction time and mass ratio of methanol to 2,6-NDCA on the 2,6-NDCA conversion were investigated. It was found that all the four factors had significant effect on the conversion. The optimum reaction conditions were reaction temperature 215 ℃,mass percentage of catalyst 3%, reaction time 3 h, mass ratio of methanol to 2,6-NDCA 6∶1. The 2,6-NDCA conversion at above condition was 92.80%.
基金Project supported by the National Natural Science Foundations of China (Grant Nos.20673050 and 20973089)
文摘This paper reports that the low-temperature heat capacities of pyridine-2,6-dicarboxylic acid were measured by a precision automatic calorimeter over a temperature range from 78 K to 380 K.A polynomial equation of heat capacities as a function of temperature was fitted by the least-squares method.Based on the fitted polynomial,the smoothed heat capacities and thermodynamic functions of the compound relative to the standard reference temperature 298.15 K were calculated and tabulated at intervals of 5 K.The constant-volume energy of combustion of the compound was determined by means of a precision rotating-bomb combustion calorimeter.The standard molar enthalpy of combustion of the compound was derived from the constant-volume energy of combustion.The standard molar enthalpy of formation of the compound was calculated from a combination of the datum of the standard molar enthalpy of combustion of the compound with other auxiliary thermodynamic quantities through a Hess thermochemical cycle.
基金Supported by the Science and Technology Fund of Hengyang Science and Technology Bureau (No. 2008KS035)the Construct Program of the Key Discipline in Hunan Province
文摘A new trinuclear nickel complex,[Ni3(pdc)3(2,2'-bipy)3(H2O)2]·2H2O(H2pdc = pyridine 2,6-dicarboxylic acid,2,2'-bipy = 2,2'-bipyridine) has been hydrothermally synthesized and characterized by IR,elemental analysis and X-ray diffraction methods.Crystal data for this complex:monoclinic,space group P21/n,a = 21.206(4),b = 10.002(2),c = 28.066(6),β = 108.18(3)°,C51H41N9Ni3O16,Mr = 1212.06,V = 5.656(2) nm3,Dc = 1.423 g·cm-3,μ(MoKα) = 1.062 mm-1,Z = 4,F(000) = 2488,GOOF = 1.034,the final R = 0.0543 and wR = 0.1237 for 6149 observed reflections with Ⅰ > 2σ(Ⅰ).In the complex,three nickel(Ⅱ) ions are bridged by the pyridine 2,6-dicarboxylic acid groups,and all nickel(Ⅱ) ions are seven-coordinated by nitrogen atoms of 2,2'-bipyridine and pyridine 2,6-dicarboxylic acid and oxygen atoms from pyridine 2,6-dicarboxylic and water to adopt a severely distorted pentagonal bipyramidal geometry.The emission and excitation peaks of the complex in ethanol solutions are located at 336 and 316 nm,respectively.
