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 he...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
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...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
A novel pyrazolone pyridine-containing ligand, 2,6-bis（1-phenyl-4-ethoxycarbonyl-5-pyrazolone-3-yl）pyridine （H2L） was designed and synthesized from pyridine-2,6-dicarboxylic acid （1）, and its Eu（III） and Tb（...A novel pyrazolone pyridine-containing ligand, 2,6-bis（1-phenyl-4-ethoxycarbonyl-5-pyrazolone-3-yl）pyridine （H2L） was designed and synthesized from pyridine-2,6-dicarboxylic acid （1）, and its Eu（III） and Tb（III） complexes were prepared. The ligand and complexes were characterized in detail based on FT-IR spectra, ^1H NMR, elemental analysis and thermal analysis, and the formula of Ln2L3·4H2O （Ln=Eu or Tb） of rare earth complexes was confirmed. The UV-vis absorption spectra and photoluminescence properties of the complexes were investigated, which showed that the Eu（III） and Tb（III） ions could be sensitized efficiently by the ligand （H2L） and emit the photolumi- nescence with high intensity, narrow half-peak width, and monochromic light. The results indicated that the complexes showed potential as excellent luminescent materials.展开更多
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.
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.
基金Project supported by the National Natural Science Foundation of China (21071152)
文摘A novel pyrazolone pyridine-containing ligand, 2,6-bis（1-phenyl-4-ethoxycarbonyl-5-pyrazolone-3-yl）pyridine （H2L） was designed and synthesized from pyridine-2,6-dicarboxylic acid （1）, and its Eu（III） and Tb（III） complexes were prepared. The ligand and complexes were characterized in detail based on FT-IR spectra, ^1H NMR, elemental analysis and thermal analysis, and the formula of Ln2L3·4H2O （Ln=Eu or Tb） of rare earth complexes was confirmed. The UV-vis absorption spectra and photoluminescence properties of the complexes were investigated, which showed that the Eu（III） and Tb（III） ions could be sensitized efficiently by the ligand （H2L） and emit the photolumi- nescence with high intensity, narrow half-peak width, and monochromic light. The results indicated that the complexes showed potential as excellent luminescent materials.
