Intramolecular Hydrogen Bonding of a Chloride Acceptor Supported by a Dinuclear Nickel(II) Complex with N-Salicylidene Hydrazide Ligand: Crystal Structure and Magnetic Properties.

The dinuclear phenoxido-bridged nickel(II) complex [{Ni(Hsalhyph)Cl(H2O)}2] with the hydrazone ligand H2salhyph, derived from salicylaldehyde and benzoic acid hydrazide, has been synthesized and structurally characterized. The dinuclear Ni2O2 core unit of the complex facilitates the formation of intramolecular O-H ···Cl hydrogen bonds. The chlorido ligand is involved in additional N-H ···Cl hydrogen bonding leading to an aggregation of the dinuclear complexes forming one-dimensional staged chains. Within the chains the supramolecular structure is governed by hydrogen bonding and π-π-stacking interactions. In the crystal structure two additional DMF molecules of crystallization are present per dinuclear complex. The DMF molecules are located between the chains and involved in O-H ···O=C hydrogen bonding with the aqua ligands of the dinickel core. Magnetic susceptibility measurements show the presence of antiferromagnetic exchange interactions ( H = - JS1 S2) with J = -14.8 cm-1 between the nickel(II) ions and indicate a zero-field-splitting of D = 12.6 cm-1. [ABSTRACT FROM AUTHOR]