Die rotationsfehlgeordnete Kristallstruktur von Tropyliumbromid C7H7+Br–/ The Rotationally Disordered Crystal Structure of Tropylium Bromide C7H7+Br-

The crystal structure of tropylium bromide, C7H7+Br-, was solved and refined in space group type R¯3m with rotationally disordered C7rings. Restraints of identical 1,2- and 1,7-C-C bond lengths as well as identical 1,3- and 1,6-C-C separations within a flat C7H7moiety were applied. The refinement converged to a regular C7heptagon with C-C bond lengths of 139.1(1) pm. C7H7+Br-reacts with Mo(CO)3(CH3CN)3to form C7H7Mo(CO)2Br.