Crystal structure of tetraaqua[2-(pyridin-2-yl)-1H-imidazole-kappa N-2(2),N-3]iron(II) sulfate

In the title compound, [Fe(C8H7N3)(H2O)(4)]SO4, the central Fe-II ion is octahedrally coordinated by two N atoms from the bidentate 2-(pyridin-2-yl)-1H-imidazole ligand and by four O atoms of the aqua ligands. The largest deviation from the ideal octahedral geometry is reflected by the small N-Fe-N bite angle of 76.0 (1)degrees. The Fe-N coordination bonds have markedly different lengths [2.1361 (17) and 2.243 (2) angstrom], with the shorter one to the pyrimidine N atom. The four Fe-O coordination bond lengths vary from 2.1191 (18) to 2.1340 (17) angstrom. In the crystal, the cations and anions are arranged by means of medium-strength O-H center dot center dot center dot O hydrogen bonds into layers parallel to the ab plane. Neighbouring layers further interconnect by N-H center dot center dot center dot O hydrogen bonds involving the imidazole fragment as donor group to one sulfate O atom as an acceptor. The resulting three-dimensional network is consolidated by C-H center dot center dot center dot O, C-H center dot center dot center dot pi and pi-pi interactions