Crystal structure of tetraaqua(5,5′-dimethyl-2,2′-bipyridyl-κ2N,N′)iron(II) sulfate

Abstract

In the title compound, [Fe(C12H12N2)(H2O)4]SO4, the central FeII ion is coordinated by two N atoms from the 5,5′-dimethyl-2,2′-bipyridine ligand and four water O atoms in a distorted octahedral geometry. The Fe—O coordination bond lengths vary from 2.080 (3) to 2.110 (3) Å, while the two Fe—N coordination bonds have practically identical lengths [2.175 (3) and 2.177 (3) Å]. The chelating N—Fe—N angle of 75.6 (1)° shows the largest deviation from an ideal octahedral geometry; the other coordination angles deviate from ideal values by 0.1 (1) to 9.1 (1)°. O—H...O hydrogen bonding between the four aqua ligands of the cationic complex and four O-atom acceptors of the anion leads to the formation of layers parallel to the ab plane. Neighbouring layers further interact by means of C—H...O and π–π interactions involving the laterally positioned bipyridine rings. The perpendicular distance between π–π interacting rings is 3.365 (2) Å, with a centroid–centroid distance of 3.702 (3) Å.

Keywords

• crystal structure
• 5,5′-dimethyl-2,2′-dipyridyl
• tetraaquairon(II) complex
• sulfate
• bipyridine ligand
• hydrogen bonding
• π–π interactions