Theoretical studies of conjugated systems containing CC and CN fragments and their alkyl and amino derivatives

Ab initio molecular orbital theory has been systematically employed to investigate the structures, energies, and conformations of 27 nitrogen‐containing compounds. A force field has been developed, on the basis of available experimental and theoretical data, to permit extension of the molecular orbital‐based molecular mechanics calculations to hetero‐conjugated systems. Structures, heats of formation, and conformations of more than 65 molecules were studied by the developed force field and the results were compared with the available experimental data.