Conformational analysis of cycloheptanone and cycloheptanethione

The conformations of cycloheptanone and cycloheptanethione were studied at the B3LYP and CCSD(T) levels of theory using the 6-311 + G(d,p) basis set. Both molecules are remarkably similar in their conformational properties and are characterized by the presence of a broad potential well centred around the symmetrical twist-chair conformation. Pseudorotational barriers are found to be higher than in cycloheptane, whereas the transition from the chair family to the twist-boat conformation requires less energy.