Syntheses and crystal structures of the one-dimensional coordination polymers formed by [Ni(cyclam)]2+ cations and 1,3-bis-(3-carb-oxy-prop-yl)tetra-methyl-disiloxane anions in different degrees of deprotonation.

The asymmetric units of the title compounds, namely, catena-poly[[(1,4,8,11-tetra-aza-cyclo-tetra-decane-κ4 N 1,N 4,N 8,N 11)nickel(II)]-μ-1,3-bis-(3-carboxyl-ato-prop-yl)tetra-methyl-disiloxane-κ2 O:O'], [Ni(C10H24O5Si2)(C12H24N4)] 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)]-μ-4-({[(3-carb-oxy-prop-yl)di-methyl-sil-yl]-oxy}di-methyl-sil-yl)butano-ato-κ2 O:O'] per-chlorate], {[Ni(C10H25O5Si2)(C12H24N4)]ClO4} n (II), consist of one (in I) or two crystallographically non-equivalent (in II) centrosymmetric macrocyclic cations and one centrosymmetric dianion (in I) or two centrosymmetric monoanions (in II). In each compound, the metal ion is coordinated by the four secondary N atoms of the macrocyclic ligand, which adopts the most energetically stable trans-III conformation, and the mutually trans O atoms of the carboxyl-ate in a slightly tetra-gonally distorted trans-NiN4O2 octa-hedral coordination geometry. The crystals of both types of compounds are composed of parallel polymeric chains of the macrocyclic cations linked by the anions of the acid running along the [101] and [110] directions in I and II, respectively. In I, each polymeric chain is linked to four neighbouring ones by hydrogen bonding between the NH groups of the macrocycle and the carboxyl-ate O atoms, thus forming a three-dimensional supra-molecular network. In II, each polymeric chain contacts with only two neighbours, forming hydrogen bonds between the partially protonated carb-oxy-lic groups of the bridging ligand. As a result, a lamellar structure is formed with the layers oriented parallel to the (11) plane.