Intra- and supramolecular interactions in cis,mer-diaquatris(1H-imidazole-κN3)(terephthalato-κO)cobalt(II) monohydrate

Abstract

In the title compound, [Co(C8H4O4)(C3H4N2)3(H2O)2]·H2O, the cisoid angles are in the range 85.59 (5)–93.56 (5)°, while two equal transoid angles deviate significantly from the ideal linear angle, the third being almost linear. One carboxylate group is almost coplanar [1.23 (13)°] with the plane of its parent aromatic ring, although it has one O-atom donor involved in one coordination and one hydrogen bond as acceptor. The other carboxylate group does not coordinate and is rotated out of this plane with a torsional twist of 17.27 (20)°. The coordination neutral entity, based on aqua ligands and two cyclic co-ligands seems, at first sight, monomeric. Strongly tight, via one intramolecular hydrogen bond between aqua and carboxylate O atoms, it brings out a quasi-planar six-membered ring around the CoII atom, turning the CoN3O3 coordination octahedron into a new building block. The rigidity of this feature associated with several hydrogen-bonded arrays yields an extended structure. In the resulting supramolecular packing, a binuclear hydrated CoII assembly, built up from triple strands driven by different heterosynthons, embodies the synergy of coordination, covalent and hydrogen bonds.