BIS(PHENYL)-1-CARBAMOYLGUANIDINIUM N-PHENYLCARBAMIDONITRILATE - REVISION OF AN EARLIER PROPOSAL

Further refinement of the X-ray diffraction structure factors from the purported neutral molecular complex of 1,5-diphenylbiuret and phenylc arbamidonitrile shows that this material is actually the title salt, C 14H15N4O+.C8H6N3O- [IUPAC name: 1-phenyl-3(N-phenylcarbamoyl)guanidini um 3-phenyl-1-ureidonitrilate]. The vital clue was Mat one of the post ulated C-O bond lengths in the presumed 1,5-diphenylbiuret component w as too long for a carbonyl group; then unconstrained refinement, witho ut any assumptions, showed that both proton transfer had occurred and the cation was bis(phenyl)-1-carbarmoylguanidinium, the postulated C-O group having been replaced by C-NH2.