【摘要】 用分子中原子的平衡电负性对分子图进行着色,在距离矩阵的基础上结合分子中各原子的支化度构建一组拓扑指数ND,它对分子结构实现唯一性表征,具有优良的结构选择性,用ND指数对链烷烃的加和型性质及同系递变规律进行研究,结果表明烷烃加和型性质P可用下式来定量描述:P=aND1+bND2+cND3+d,其中a,b,c,d为常数.用该式对85种链烷烃的标准生成焓△fHm(?),标准熵△fSm(?),标准生成吉布斯自由能△fGm(?)及67种链烷烃的摩尔体积Vm,摩尔折射度Rm进行预测,预测值与实验值吻合良好.更多还原

【Abstract】 A group of topological index ND data based on distance matrix and branch vertex of atoms in a molecule was put forward by colouring atoms in the molecular graph with equilibrium electronegativity, which appears unique to the molecular structures and has excellent structural selectivity. The results show that the additive property P of alkanes could be described as follows: P=aND1+bND2+cND3+d by study on the additive property of alkanes and their homologous regularity using topological index ND, where a, b, c and d are conferred as constants. The calculated values conform very much to the experimental ones of gas enthalpy (△fHm(?)), entropy (△fSm(?)), Gibbs energy (△fGm(?)) of 85 alkanes and molar volume (Vm), molar refraction (Rm) of 67 alkanes from literatures using the formula above.更多还原