Bis[2-hydroxy-N'-(3-phenylprop-2-enylidene)benzohydrazidato-kappa2N',O]bis(methanol-kappaO)nickel(II) and bis[2-hydroxy-N'-(3-phenylprop-2-enylidene)benzohydrazidato-kappa2N',O]bis(pyridine-kappaN)nickel(II).

ABSTRACT

In the two title complexes of cinnamaldehyde salicyloylhydrazone [or 2-hydroxy-N'-(3-phenylprop-2-enylidene)benzohydrazide], [Ni(C(16)H(13)N(2)O(2))(2)(CH(4)O)(2)], (I), and [Ni(C(16)H(13)N(2)O(2))(2)(C(5)H(5)N)(2)], (II), the Ni(II) atoms lie on crystallographic inversion centres and have distorted octahedral geometries. The equatorial plane is defined by two carbonyl O atoms and two hydrazine N atoms of two bidentate trans-oriented salicyloylhydrazone ligands. The axial positions are occupied by two O atoms from two coordinated methanol molecules in (I) and by two N atoms from two coordinated pyridine molecules in (II). There is an extended chain structure in (I) resulting from intermolecular O-H...O hydrogen bonds between coordinated methanol molecules and phenol O atoms, while (II) comprises discrete molecules. Complex (I) also exhibits weak pi-pi stacking interactions, and intramolecular O-H...N hydrogen bonds are present in both (I) and (II). The salicyloylhydrazone ligands in (I) and (II) are coordinated to the metal atom through the carbohydrazide O and N(2) atoms, not via the phenol O atom. We have established a link between the reagents used and the nuclearity of the complex formed the ligand produced by condensation between salicylhydrazide and an aldehyde leads to mononuclear complexes, while replacing the aldehyde in the reaction by a ketone leads to multinuclear complexes.