Syntheses and structures of two coordination polymers formed by Ni(cyclam)2+ cations and sulfate anions.

The asymmetric units of catena-poly[[(1,4,8,11-tetra-aza-cyclo-tetra-decane-κ4 N 1,N 4,N 8,N 11)nickel(II)]-μ2-sulfato-κ2 O 3:O 4], [Ni(SO4)(C10H24N4)] n (I), and catena-poly[[(1,4,8,11-tetra-aza-cyclo-tetra-decane-κ4 N 1,N 4,N 8,N 11)nickel(II)]-μ2-sul-fato-κ2 O 3:O 4] hemi[4,4',4'',4'''-(2,2',4,4',6,6'-hexa-methyl-[1,1'-biphen-yl]-3,3',5,5'-tetra-yl)tetra-benzoic acid] nona-hydrate], {[Ni(SO4)(C10H24N4)]2·C46H38O8·18H2O} n (II), consist of two crystallographically unique centrosymmetric macrocyclic dications and a sulfate dianion. In II it includes additionally a mol-ecule of the undissociated acid (2,2',4,4',6,6'-hexa-meth-yl[1,1'-biphen-yl]-3,3',5,5'-tetra-yl)tetra-(benzoic acid) located on a crystallographic twofold axis and nine highly disordered water mol-ecules of crystallization. In both compounds, the metal ions are coordinated in the equatorial plane by the four secondary N atoms of the macrocyclic ligand, which adopts the most energetic-ally stable trans-III conformation. Two O atoms of the sulfate anions occupy the trans-axial positions resulting in a slightly tetra-gonally distorted trans-NiN4O2 octa-hedral coordination geometry. The crystals of both compounds are composed of parallel coordination polymeric chains running along the [101] and [100] directions in I and II, respectively. The distances between the neighboring metal ions in the chains are significantly different [6.5121 (6) Å in I and 6.0649 (3) Å in II] and this peculiarity is explained by the different spatial directivity of the Ni-O coordination bonds (different S-O-Ni angles). As a result of the C-H⋯O hydrogen bonds between the methyl-ene groups of the macrocyclic ligands and the non-coordinated O atoms of the sulfate anion, the coordination-polymeric chains in I are arranged in the two-dimensional layers oriented parallel to the (010) and (101) planes, the inter-section of which provides the three-dimensional coherence of the crystals. The three-dimensional supra-molecular structure of the crystals II is determined by the network of strong hydrogen bonds formed by the carb-oxy-lic acid and the non-coordinated O atoms of the sulfate anions.