以系统命名法为基础,结合改进的支链编号规则,对脂肪族醛酮分子中的碳原子进行编号,并在此基础上建立了一种拓扑指数^iMm.以72种脂肪醛和脂肪酮的沸点为例,进行定量关系一性质相关(QSPR)研究.72种醛酮沸点与其分子支链数Nc和^0Mm,^1Mm之间存在良好的线性关系:log(720-Tb)=2.65218+0.01318Nc-0.01516^1Mm+0.0012^0Mm,复相关系数为0.99779.本方法为脂肪醛和脂肪酮沸点的归纳与定量表征、预测提供了非常有效的方法,为这类物质的气相色谱分离提供了一种方便易得的数据依据.
A modified topological index,^iMm, was proposed to establish a quantitative relationship for predicting the boiling point of 72 carbonyl compounds. The regulation of this new topological index iMm is almost based on the IUPAC systematic nomenclature. Each atom exclusive of oxygen and hydrogen was numbered and these numbers were regarded as their corresponding valences. The topological index iMm was divided into different grades according to different i values. Specifically, if i was 1, the corresponding topological index was called grade one and remarked as ^1Mm; if i was 0, the corresponding topological index was called grade zero and remarked as ^0Mm. The values of ^1Mm and ^1Mm were calculated by formulae of ^0Mm = ∑, (Ni )^0.5 and ^1Mm = ∑ (Ni*Nj)0. 5, respectively. A quantitative structure property relationship between boiling point of chain hydrocarbons and iMm was finally obtained by multiple linear regression method, that is log(720 - Tb) = 2. 652 18 + 0. 013 18 Nc - 0. 015 16 ^1Mm + 0. 001 2^0Mm(R = 0. 997 79), where Nc is the number of chain carbon.