The Synchronous 1,4-Addition of SiH2(1A1) to s-cis-buta-1,3-diene. A CI and CASSCF Study

摘要: A minimum energy path for the synchronous 1,4-addition reaction of SiH2(1A1) with s-cis-buta-l,3-diene to 1-silacyclopent-3-ene was determined by ab initio SCF and CI calculations. To analyse changes electronic structure along CASSCF calculations a population analysis were performed. From these geometrical variations it is concluded that initiated an electrophilic step involving HOMO butadiene empty p orbital SiH2. Closed shell repulsions play decisive role orientation SiH2 relative molecule. An activation 17 kJ/mol estimated exothermicity formation silacyclopentene evaluated be 283.82 kJ/mol. It follows from barrier due avoided crossing between ground first excited singlet state composite system.