Spectral studies of copper(II) complexes of tridentate acylhydrazone ligands with heterocyclic compounds as coligands: X-ray crystal structure of one acylhydrazone copper(II) complex

Six copper(II) complexes of 2-hydroxy-4-methoxybenzaldehyde nicotinoylhydrazone (H2hmbn), 2-hydroxy-4-methoxyacetophenone nicotinoylhydrazone (H2hman), 2-hydroxy-4-methoxybenzaldehyde benzoylhydrazone (H2hmbb) and 2-hydroxy-4-methoxyacetophenone benzoylhydrazone (H2hmab) have been synthesized. The complexes viz. [Cu(hmbn)]2·2H2O (1), [Cu(hman)]2 (2), [Cu(hmbb)]2·2H2O (3), [Cu(hmbb)phen]·1(1/2)H2O (4), [Cu(hmbb)(bipy)·H2O] (5) and [Cu(hmab)phen] (6) were characterized by different physicochemical techniques. The crystal structure of [Cu(hman)phen] is obtained and it has a distorted square pyramidal geometry with π–π stacking interactions and significant C–H π interactions.

A new series of copper(II) complexes of four different acylhydrazones have been prepared and their spectroscopic and structural characterization described. One of the crystal structures of synthesized copper complexes has a distorted square pyramidal geometry with strong π–π stacking and C–H⋯π interactions in its packing.Figure optionsDownload as PowerPoint slideHighlights
► Six copper(II) complexes are synthesized by using H2hmbn, H2hman, H2hmbb and H2hmab.
► A crystal structure of one of the complexes, [Cu(hman)phen] is obtained.
► Coordination geometry of the complex [Cu(hman)phen] is distorted square pyramid.
► The π–π interaction plays an important role in controlling the packing of compounds.
► C–H⋯π interactions and intermolecular hydrogen bonding are also present.