机械振动理论方法与直链烷烃性质研究

将直链烷烃分子看成是一个多自由度振动系统,用机械振动理论中的传递矩阵法计算了C2～C32直链烷烃的固有频率,分析了固有频率随化合物结构单元的变化规律.发现各阶固有频率中的基频与直链烷烃的结构型性质呈现出优良的相关性,用各阶固有频率之和表示的总频与直链烷烃的加和型性质也呈现出优艮的相关性,将两者组合后还能够反映直链烷烃的凝聚型性质的变化规律.在此基础上建立了直链烷烃的物化性能与基频和总频之间的定量相关模型.用该模型对直链烷烃的电离能、沸点、临界温度、临界压力、密度、粘度、标准生成焓、离子标准生成焓、常压热容、折光指数等10种不同类型性质的实验数据进行回归分析,相关系数均大于0.999.

Method in Mechanical Vibration Theory and Studies of Properties of Straight-chain Alkanes

A molecule of straight-chain alkanes was regarded as a multi-dimension system in mechanic vibration. A atom, or atomic group was regarded as the dispersion mass-point in it. The chemical bond in molecules was like the spring combining the dispersion mass-point. The intrinsic vibrational frequency was calculated by transmit matrix method. The change relation of the intrinsic vibration with the structure unit was discussed. It is found that there are good relationships between the fundamental frequencies and the structural properties of straight-chain alkanes, and between the sum-frequencies and the additivity properties of straight-chain alkanes as well. Combining the fundamental frequency and the sum-frequency, the relation model of the condensation properties with the fundamental frequency and sum-frequency can reflects the change law between the properties and intrinsic frequencies awfully nice. The quantitative relation model was established between the fundamental or sum frequency and properties of straight-chain alkanes. Some properties of straight-chain alkanes were predicted by the model. The results showed that there was very close relation between the frequency and the properties, and the coefficient r>0.999.