基团贡献法物性估算中分子结构自动拆解的多解问题

Multi-solution of molecular structure automatic disassembly in group contribution method

化工生产和科学研究中普遍存在物性数据不足的问题,利用基团贡献法进行物性估算是解决这一问题的有效手段。基团贡献法是一类将分子结构片段(基团)对物性的影响(贡献值)加和来预测化合物的性质的方法。目前,已有多种基团贡献法物性估算程序用于化合物性质的估算,物性估算程序的核心是分子结构的自动拆解,然而,在分子结构自动拆解中,不同的基团匹配顺序有可能造成拆解的结果出现多解或歧义,有时甚至会导致分子结构拆解失败,导致物性估算错误或无法进行。本文研究了各类基团的不同匹配顺序对分子结构自动拆解结果的影响,提出了基团优先级策略以保证拆解结果正确性,并以此为依据利用CACTVS化学工具库和Tcl语言编写了物性估算程序。以Constantinou-Gani方法为例的测试结果表明基团优先级能够解决分子结构自动拆解中的多解问题。

Group contribution method is an efficient way to estimate or predicate the thermodynamic and other properties when the experimental data is not available. The principle of a group contribution method is the determination of a component property by summing up the groups contribution.To make better use of group contribution method, many property estimation programs using group contribution method have been developed. The key step for such program is molecular automatic disassembly according to the predefined groups for a method. However, molecular structure automatic disassembly will provide different solutions using different group matching sequences, which may lead to unreliable estimation result. In this paper,the effects of different group matching sequences on disassembly results were studied, and group priority method was proposed to make sure accurate molecular automatic disassembly. Anestimation program was developed using Tel language and CACTVS package based on group priority and was tested using Constantinou-Gani contribution method as example. The results show that the group priority method can help to obtain correct disassembly solution.