Intramolecular charge transfer in some donor-acceptor molecules as N-picrylauramine

Intramolecular charge transfer in picryl derivatives of benzophenonimide has been studied. Dipole moments and NMR spectra reveal that the contribution of charge transfer structures to the ground state is of minor importance in contrast with what could be expected. The discrepancy can be explained if a geometrical structure is assumed which closely resembles that of N,N-diphenyl-N'-picrylhydrazyl.