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

Amaya, Toru; Sakane, Hiroyuki; Nakata, Takuto; Hirao, Toshikazu

doi:10.1351/PAC-CON-09-10-13

Pure Appl. Chem., 2010, Vol. 82, No. 4, pp. 969-978

http://dx.doi.org/10.1351/PAC-CON-09-10-13

Published online 2010-03-19

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

Toru Amaya, Hiroyuki Sakane, Takuto Nakata and Toshikazu Hirao*

Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Yamada-oka, Suita, Osaka 565-0871, Japan

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.