Hydrogen-bonded supramolecular networks of N,N'-bis(4-pyridylmethyl)oxalamide and 4,4'-{[oxalylbis(azanediyl)]dimethylene}dipyridinium dinitrate.

The molecule of N,N'-bis(4-pyridylmethyl)oxalamide, C(14)H(14)N(4)O(2), (I) or 4py-ox, has an inversion center in the middle of the oxalamide group. Adjacent molecules are then linked through intermolecular N-H...N and C-H...O hydrogen bonds, forming an extended supramolecular network. 4,4'-{[Oxalylbis(azanediyl)]dimethylene}dipyridinium dinitrate, C(14)H(16)N(4)O(2)(2+).2NO(3)(-), (II), contains a diprotonated 4py-ox cation and two nitrate counter-anions. Each nitrate ion is hydrogen bonded to four 4py-ox cations via intermolecular N-H...O and C-H...O interactions. Adjacent 4py-ox cations are linked through weak C-H...O hydrogen bonding between an alpha-pyridinium C atom and an oxalamide O atom, forming a two-dimensional extended supramolecular network.