Mono- and dinuclear platinum(II) complexes via single and double cycloplatinations of Nʹ-(arylidene)benzohydrazides

• Mono- and dicycloplatinates of Nʹ-(arylidene)benzohydrazides (H3Ln) were synthesized.
• Characterization was done by elemental analysis, X-ray crystallography and spectroscopy.
• Identities of the complexes were established as [Pt(HLn)(PPh3)] and [Pt2(μ-Ln)(PPh3)2Cl].
• (HLn)2− is CNO-donor and (μ-Ln)3− is CNO-donor on one side and CN-donor on the other side.

Monocycloplatinated complexes [Pt(HLn)(PPh3)] were synthesized using [Pt(dmso)2Cl2], Nʹ-(arylidene)benzohydrazides (H3Ln, arylidene = 1-naphthylidene or 9-phenanthrylidene), NaOAc·3H2O, and PPh3 in 1:1:1:2 mol ratio. The same reagents in 2:1:1:2 mol ratio provided the dicycloplatinated complexes [Pt2(μ-Ln)(PPh3)2Cl]. All the complexes have been characterized by elemental analysis, X-ray crystallographic and spectroscopic measurements. X-ray structures reveal that (HLn)2− acts as pincer-like CNO-donor in [Pt(HLn)(PPh3)], while the dinucleating (Ln)3− behaves as pentadentate ligand and acts is CNO-donor to one metal centre and CN-donor to the second metal centre in [Pt2(μ-Ln)(PPh3)2Cl]. The spectroscopic (IR, UV–Vis and NMR) features of both types of complexes are in agreement with their corresponding identities.

Syntheses, X-ray structures and spectroscopic properties of mono- and dicycloplatinated complexes, [Pt(HLn)(PPh3)] and [Pt2(μ-Ln)(PPh3)2Cl] (H3Ln = Nʹ-(1-naphthylidene/9-phenanthrylidene)benzohydrazides) are described. (HLn)2− shows the CNO-coordination mode in [Pt(HLn)(PPh3)], while (μ-Ln)3− is CNO-donor to one metal centre and CN-donor to the second metal centre in [Pt2(μ-Ln)(PPh3)2Cl].Figure optionsDownload as PowerPoint slide