A theoretical study of the bowl-to-bowl inversion of sumanene derivatives

Abstract

A theoretical study was conducted on the bowl-to-bowl inversion of sumanene: its benzylic mono-, di-, and trianion species and its mono-, di-, and trinaphthosumanenes. The use of B3LYP/6-311+G(2d,p) for the B3LYP/6-31G(d,p)-optimized geometries approximately reproduced the experimental values for the bowl-to-bowl inversion of sumanene, and its benzylic mono- and dianion species. The value for the trianion was estimated to be around 21 kcal/mol using the above levels. The investigation of naphthosumanenes clearly indicated a noted increase in the inversion barrier with additional fused rings. The calculated inversion barrier for mononaphthosumanene also correctly reproduced the experimental value (32.2 kcal/mol) using the above levels (31.4 kcal/mol). The calculated barrier for trinaphthosumanene reached 63.8 kcal/mol, therefore, the bowl-to-bowl inversion is less likely to occur under realistic conditions.