Transition metal complexes with thiosemicarbazide-based ligands. LIII. [4-(2-diphenylphosphino-alpha-ethoxybenzyl-kappa P)-S-methyl-1-(4-oxidopent-3-en-4-ylidene-kappa O)-thiosemicarbazido-kappa(2) N-1, N-4]nickel (II)

Abstract

The title compound, [Ni(C28H30N3O2PS)], crystallizes with two independent molecules in the asymmetric unit. The Ni-II atoms are in significantly deformed square-planar environments formed by an ONNP donor set from a thiosemicarbazide-based tetradentate ligand. The Ni-II atom and the ONN donor atoms are nearly coplanar, while the P atom deviates from their mean planes by 0.278 (4) and 0.202 (4) angstrom for the two independent molecules. The P-containing chelate rings are remarkably non-planar, adopting a boat conformation, which is unusual for chelate rings in transition metal complexes with thiosemicarbazide-based tetradentate ligands. The orientation of the ethoxy group bonded to this chelate ring is caused by an intramolecular C-H center dot center dot center dot pi interaction with the opposing phenyl ring. There are no hydrogen bonds; instead, numerous intermolecular C-H center dot center dot center dot pi interactions dominate in the crystal packing.