ELECTRONIC SPECTRA OF ISOMERS OF REDUCED 1-ALKYL-NICOTINAMIDE

A self-consistent field molecular orbital calculation has been performed on the three isomers of reduced N-alkyl-nicotinamide. The calculated excited states show reasonably good agreement with experiment. The first excited state is one in which electrons leave the ring nitrogen but do not greatly increase the electron density of the amide oxygen as is generally assumed. The calculated π-dipole moments for the ground and first excited states of the transoid 1,4-isomer are in excellent agreement with the total experimental moments. The calculated electron densities of the ring carbon atoms in the 1,4-isomer also are in agreement with observed NMR chemical shifts. © 1969.