Bis(2-{1-[(2,4,6-trimethylphenyl)imino]ethyl}pyrrol-1-ido-κ2N,N′)nickel(II): a supramolecular structure formed by C-H•••π(arene) hydrogen bonds

Nitrogen-based polydentate ligands are of interest owing to their flexible complexation to transition metal atoms. For the title compound, [Ni(C15H17N2)(2)], a transition metal complex formed by the coordination of two identical N,N'-bidentate mono(imino) pyrrolyl ligands to an Ni-II centre, an X-ray crystal diffraction study indicates that the two ligands show an inverted arrangement with respect to one another around the Ni-II centre, which is located on a crystallographic inversion centre. The planes of the aromatic substituents at the imine N atoms of the ligands show dihedral angles of 85.91 (5)degrees with respect to the NiN4 plane. The Ni-N bond lengths are in the range 1.9072 (15)-1.9330 (15) angstrom and the N-imino-Ni-N-pyrrole bite angles are 83.18 (6)degrees. The Ni-N-pyrrole bond is substantially shorter than the Ni-N-imino bond. Molecules are linked into an extensive network by means of intermolecular C-H center dot center dot center dot pi(arene) hydrogen bonds in which every molecule acts both as hydrogen-bond donor and acceptor. The supramolecular assembly takes the form of an infinite two-dimensional sheet.