supramolecular structures of N(4)-substituted 2,4-diamino-6-benzyloxy-5-nitrosopyrimidines.

The molecular and supramolecular structures of eight N(4)-substituted 2,4-diamino-6-benzyloxy-5-nitrosopyrimidines are discussed, along with one analogue containing no nitroso substituent. The nitroso derivatives all exhibit polarized molecular-electronic structures leading to extensive charge-assisted hydrogen bonding between the molecules. The intermolecular interactions include hard hydrogen bonds of N-H...O and N-H...N types, together with O-H...O and O-H...N types in the monohydrate of 2-amino-6-benzyloxy-4-piperidino-5-nitrosopyrimidine, soft hydrogen bonds of C-H...O, C-H...pi(arene) and N-H...pi(arene) types and aromatic pi...pi stacking interactions. The predominant supramolecular structure types take the form of chains and sheets, but no two of the structures determined here exhibit the same combination of hydrogen-bond types.