Crystal structure of tetraaqua[2-(pyridin-2-yl)-1H-imidazole-κ2N2,N3]iron(II) sulfate

Abstract

In the title compound, [Fe(C8H7N3)(H2O)4]SO4, the central FeII ion is octahedrally coordinated by two N atoms from the bidentate 2-(pyridin-2-yl)-1 H-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)°. The Fe - N coordination bonds have markedly different lengths [2.1361 (17) and 2.243 (2) Å], 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) Å. In the crystal, the cations and anions are arranged by means of medium-strength O - H⋯O hydrogen bonds into layers parallel to the ab plane. Neighbouring layers further interconnect by N - H⋯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⋯O, C - H⋯π and π-π interactions.