Structure and infrared-spectroscopy of the C-11 molecule

Abstract

Linear, cyclic and three-dimensional structures of C-11 have been studied with ab initio methods. At the MP2/6-31G(d) level, a cyclic structure is clearly the ground state, about 5 kcal/mol below the lowest linear structure. The three-dimensional structure proposed by van Vechten and Keszler is less stable by at least 200 kcal/mol. Arguments are presented in favor of assignment of the 1804 and 1844 cm-1 matrix IR bands to cyclic C-11, and of the 1818 cm-1 band to cyclic C-10.