Effect of substituents on the electronic structure of cyclic oxides and its change in the interaction of oxides with an electron acceptor. Quantum chemical investigation

Abstract

Electronic characteristics of substituted three-, four-and five-membered cyclic oxides and their complexes with an electron acceptor CH; have been calculated by the CNDO/2 method. The reactivity ratio of these cyclic oxides in their cationic copolymerization is in agreement with the calculated complexation energy of cyclic oxides with the electron acceptor. Der EinfluP der Substituenten auf die elektronische Struktur cyclischer Oxide und die Veranderung dieser Struktur bei der Wechselwirkung der Oxide mit einem Elektronenacceptor. Quantenchemische UntersuchungenDie elektronischen Eigenschaften von substituierten drei-, vier-und funfgliedrigen cyclischen Oxiden sowie ihrer Komplexe mit dem Elektronenacceptor CH; wurden mit Hilfe der CNDO/a-Methode berechnet. Das Reaktivitatsverhaltnis der Oxide bei der kationischen Copolymerisation stimmt mit den berechnetcn Komplexbildungsenergien dieser Oxide mit Elektronenacceptoren gut uberein. Bnusnue aa&ecmumeneii na e~teicmpon~ylo cmpyicmypy yumuuecicux oicuceii u na ee u~&enenue npu saauwoc3eiicnzsuu oicuceii c ~e~mpoltoaicyenmopo&. h"sanmosbxu&uuecicoe uccAedosanueMeTOAOM IIqAII/2 PaCCYMTaHM 3JIeKTpOHHbIe XapaKTepHCTMKH 3aMeqeHHbIX TpeX-, YeTbIpeX-M IIRTKYJIeHHbIX qHKJIHYeCKHX OKMCefi, a TaKme KOMnJIeKCOB 3TMX OKHCefi C 3JIeKTpOHOaKqellTOpOM CHg. OTHOCHTeJIbHaR PeaKqHOH-HaR CllOCO6HOCTb l[HKJIMYeCKHX OKHCefi I I P M MX KaTHOHHOfi COIlOJIMMepM3aqHH KOppeJIMpyeT C paCseTHOfi 3HepFMefi KOMIlJIeKCOO6pa3OBaHHFI qMKJIHYeCKMX OKHCefl C 3JIeKTpOHOaKqellTOpOM.

Ring-opening polymerization of glycidylic compounds: influence of the glycidylic oxygen in the coordinative mechanism

“…A second important effect to be considered is the coordination ability of the monomer on the active sites in the catalyst. For the mechanism described above, the most important coordinative site in the monomer is the oxiranic oxygen, whose relative basicity is affected by the oxirane substituents 21) . It should also be taken into account that there may be a cooperative or competitive effect of other coordinative centers which are present in the neighboring substituents 22,23) .…”