Yıldız, Cem BurakAzizoğlu, Akın13.07.20192019-07-1613.07.20192019-07-1620161610-2940https://dx.doi.org/10.1007/s00894-016-3016-yhttps://hdl.handle.net/20.500.12451/2361The formation of silaspiropentane from addition of singlet silacyclopropylidene 1 and silacyclopropylidenoid 8 to ethylene has been investigated separately at the B3LYP, X3LYP, WB97XD, and M05–2X theories using the 6–31+G(d,p) basis set. The silacycloproylidenoid addition follows a stepwise route. In contrast, a concerted mechanism occurs for silacyclopropylidene addition. Moreover, the intramolecular rearrangements of silaspiropentane 9 to methylenesilacyclobutane 11 and 2-silaallene + ethylene 12 have been studied extensively. The required energy barrier for the isomerization of 9 to 10 was determined to be 44.0 kcal mol-1 at the B3LYP/6–31+G(d,p) level. After formation of 10, the rearrangement to methylenesilacyclobutane 12 is highly exergonic by -15.9 kcal mol-1, which makes this reaction promising. However, the conversion of 9 to 11 is calculated to be quite endergonic, by 26.5 kcal mol-1. © 2016, Springer-Verlag Berlin Heidelberg.eninfo:eu-repo/semantics/closedAccessAddition ReactionDFTSilacyclopropylideneSilacyclopropylidenoidSilaspiropentaneArticle22710.1007/s00894-016-3016-yQ2N/A