苯氧乙酸嘧霉胺盐的低温热容和热力学性质研究

Heat Capacity and Thermodynamic Properties of Crystalline Pyrimethanil Phenoxyacetate(C_(20)H_(21)N_(3)O_(3))

用精密自动绝热量热计测定了苯氧乙酸嘧霉胺盐在81～380K之间的低温热容．结果表明，该化合物在81-328K之间无相变和热异常现象发生，在328～354K之间发生固-液熔化，其熔化温度、摩尔熔化焓和摩尔熔化熵分别为（349．380．03）K，（34279±10）kJ／mol和（98．13±0．05）J／（K·mol）．根据热力学函数关系式计算出苯氧乙酸嘧霉胺盐在80～325K之间以标准状态（298．15K）为基准的热力学函数值．

Low-temperature heat capacities of Pyrimethanil phenoxyacetate （ C20H21N3O3 ） were precisely measured with a high-precision automated adiabatic calorimeter over the temperature range between 81 to 380 K. The compound was observed to melt at（349.38 ±0.04） K. The molar enthalpy △fusHm, and entropy of fusion, △fusSm of the compound were determined to be （34 279 ± 10） J/mol, （98.13 ± 0.05 ） J/（ mol · K）, respectively. The thermodynamic function data relative to the reference temperature（298.15 K） were calculated based on the heat capacities measurements in the temperature range from 80 K to 325 K.