trans-(5,7,7,12,14,14-Hexamethyl-1,4,8,11-tetra-aza-cyclo-tetra-deca-4,11-diene-κN,N',N'',N''')bis-(nitrito-κN)cobalt(III) perchlorate hemihydrate.

The asymmetric unit of the title Co(III) complex, [Co(NO(2))(2)(C(16)H(32)N(4))]ClO(4)·0.5H(2)O, comprises two complex cations, two perchlorate anions and a water mol-ecule of crystallization. The Co(III) atoms exist within distorted octa-hedral N(6) geometries defined by four N atoms of the macrocycle ligand and trans-N atoms derived from the nitrite anions. Systematic variations in the Co-N bond lengths are correlated with the presence of intra-molecular N-H⋯O(nitrite) hydrogen bonds. In the crystal, water-O-H⋯O(perchlorate) hydrogen bonds, involving one of the independent perchlorate anions only, lead to supra-molecular chains along the b-axis direction. The three-dimensional architecture is consolidated by numerous C-H⋯O inter-actions. The crystal studied was a non-merohedral, racemic twin.