Crystal structure of bis(bis{(E)-[(6-{(E)-[(4-fluorobenzyl)imino]methyl}pyridin-2-yl)methylidene](4-fluorophenyl)amine}nickel(II)) tetrabromide nonahydrate

Abstract

In the title complex, [Ni(C21H17F2N3)(2)](2)Br-4 center dot 9H(2)O, there are two independent metal complexes per asymmetric unit and two ligands per metal complex. The structural features (bond lengths and angles) of the two complexes are almost identical. In each complex, the nickel(II) ion is coordinated in an octahedral environment by six N atoms from two chelating (9E)-N-({6-[(E)-(4-fluorobenzylimino)methyl]pyridin-2-yl}-methylene)(4-fluorophenyl)methanammine ligands. The Ni-N bond lengths range from 1.973 (2) to 2.169 (2) angstrom, while the chelate N-Ni-N angles range from 77.01 (10) to 105.89 (9)degrees. Additionally, there are four bromide anions and nine solvent water molecules within the asymmetric unit. The water molecules form a hydrogen-bonded network, displaying C-H center dot center dot center dot O, C-H center dot center dot center dot Br, O-H center dot center dot center dot Br, O-H center dot center dot center dot O and O-H center dot center dot center dot F interactions into layers parallel to (111). In each unit, the fluorophenyl rings of one ligand are stacked with the central ring of the other ligand via pi-pi interactions, with the closest centroid-to-plane distances being 3.445 (5), 3.636 (5), 3.397 (5) and 3.396 (5) angstrom.