title: Crystal structure of tetra-aqua-(5,5'-dimethyl-2,2'-bipyridyl-κ(2) N,N')iron(II) sulfate.
abstract: In the title compound, [Fe(C12H12N2)(H2O)4]SO4, the central Fe(II) ion is coordinated by two N atoms from the 5,5'-dimethyl-2,2'-bi-pyridine ligand and four water O atoms in a distorted octa-hedral 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 octa-hedral 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 inter-act by means of C-H⋯O and π-π inter-actions involving the laterally positioned bi-pyridine rings. The perpen-dicular distance between π-π inter-acting rings is 3.365 (2) Å, with a centroid-centroid distance of 3.702 (3) Å.
authors.affiliation: Laboratoire de Chimie, Ingénierie Moléculaire et Nanostructures (LCIMN), Université Ferhat Abbas Sétif 1, Sétif 19000, Algeria.
authors.forename: Yamine
authors.initials: Y
authors.lastname: Belamri
authors.affiliation: Laboratoire de Chimie, Ingénierie Moléculaire et Nanostructures (LCIMN), Université Ferhat Abbas Sétif 1, Sétif 19000, Algeria.
authors.forename: Fatima
authors.initials: F
authors.lastname: Setifi
authors.affiliation: Vinča Institute of Nuclear Sciences, Laboratory of Theoretical Physics and Condensed Matter Physics, PO Box 522, University of Belgrade, 11001 Belgrade, Serbia.
authors.forename: Bojana M
authors.initials: BM
authors.lastname: Francuski
authors.affiliation: Vinča Institute of Nuclear Sciences, Laboratory of Theoretical Physics and Condensed Matter Physics, PO Box 522, University of Belgrade, 11001 Belgrade, Serbia.
authors.forename: Sladjana B
authors.initials: SB
authors.lastname: Novaković
authors.affiliation: Département de Technologie, Faculté de Technologie, Université 20 Août 1955-Skikda, BP 26, Route d'El-Hadaiek, Skikda 21000, Algeria ; Unité de Recherche de Chimie de l'Environnement et Moléculaire Structurale (CHEMS), Université Constantine 1, Constantine 25000, Algeria.
authors.forename: Setifi
authors.initials: S
authors.lastname: Zouaoui
keywords: 5,5′-dimethyl-2,2′-dipyrid­yl; bi­pyridine ligand; crystal structure; hydrogen bonding; sulfate; tetra­aqua­iron(II) complex; π–π inter­actions