Mechanochemical Solid-State Polymerization. VI. Quantum Chemical Considerations for Structural Criteria of Mechanically Polymerizable Vinyl Monomers.
作者:Shin-ichi KONDO、Katsuyuki MURASE、Masayuki KUZUYA
DOI:10.1248/cpb.42.768
日期:——
To provide the structural criteria for mechanically polymerizable vinyl monomers in metallic vessels, we carried out the MO calculations (AM1 method) of several acrylamide, acrylate and styrene derivatives as model compounds for such reactions. It was found that the nature of LUMO of vinyl monomers is closely related to the capability for initiation of mechanochemical polymerization. The following requisite concerning the nature of LUMO was shown to be a necessary condition for the activity of such reactions : Even if the LUMO energy is lower than 0.166eV in the AM1 scheme, the LUMO coefficient must be highly localized in the vinyl group. When the monomer does not meet this criterion, the introduction of a saturated group such as an alkyl group to insulate electronically the π-electron system of vinyl group from the rest of the molecules will lead to the mechanically polymerizable monomers.
为了提供金属容器中可机械聚合的乙烯基单体的结构标准,我们对几种丙烯酰胺、丙烯酸酯和苯乙烯衍生物作为此类反应的模型化合物进行了 MO 计算(AM1 方法)。研究发现乙烯基单体的LUMO性质与机械化学聚合的引发能力密切相关。以下有关 LUMO 性质的必要条件被证明是此类反应活性的必要条件:即使 AM1 方案中 LUMO 能量低于 0.166eV,LUMO 系数也必须高度局域于乙烯基中。当单体不满足此标准时,引入饱和基团(例如烷基)以使乙烯基的π电子系统与分子的其余部分电绝缘将产生可机械聚合的单体。