A SIMPLIFIED C-H OUT-OF-PLANE FORCE FIELD FOR BENZENE, METHYLBENZENES, AND CHLOROBENZENES

Normal coordinate treatments were carried out for CH out-of-plane vibrations of benzene, methylbenzenes, and chlorobenzenes, where the motions of only the ring hydrogen atoms were taken into account. A simplified and transferable force field was introduced, force constants were refined, and 68 assigned frequencies were reproduced with a root-mean-square difference of 0.62 percent. All the CH out-of-plane fundamental frequencies were unequivocally assigned for these compounds in CS2 solution, by the aid of analysis of their combination frequencies. © 1969.