Studies on self-association of nitromethane using a CNDO/force method

Semi-empirical MO calculations using the CNDO gradient method (CNDO/force method) have been carried out to determine the geometry, stabilization energy and stretching force constants for four dimers of nitromethane: (i) cyclic, (ii) linear, (iii) antiparallel via dipole, and (iv) antiparallel via H bonds. It is found that the cyclic dimer is the most stable, having a stabilization energy of 8.22 kcal mol-1. The effects of association on the stretching force constants of nitromethane are compared with the experimental observations made earlier. © 1988.