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

Abstract

Monocycloplatinated complexes [Pt(HL < sup > n < /sup > )(PPh < inf > 3 < /inf > )] were synthesized using [Pt(dmso) < inf > 2 < /inf > Cl < inf > 2 < /inf > ], N′-(arylidene)benzohydrazides (H < inf > 3 < /inf > L < sup > n < /sup > , arylidene = 1-naphthylidene or 9-phenanthrylidene), NaOAc·3H < inf > 2 < /inf > O, and PPh < inf > 3 < /inf > in 1:1:1:2 mol ratio. The same reagents in 2:1:1:2 mol ratio provided the dicycloplatinated complexes [Pt < inf > 2 < /inf > (μ-L < sup > n < /sup > )(PPh < inf > 3 < /inf > ) < inf > 2 < /inf > Cl]. All the complexes have been characterized by elemental analysis, X-ray crystallographic and spectroscopic measurements. X-ray structures reveal that (HL < sup > n < /sup > ) < sup > 2- < /sup > acts as pincer-like CNO-donor in [Pt(HL < sup > n < /sup > )(PPh < inf > 3 < /inf > )], while the dinucleating (L < sup > n < /sup > ) < sup > 3- < /sup > behaves as pentadentate ligand and acts is CNO-donor to one metal centre and CN-donor to the second metal centre in [Pt < inf > 2 < /inf > (μ-L < sup > n < /sup > )(PPh < inf > 3 < /inf > ) < inf > 2 < /inf > Cl]. The spectroscopic (IR, UV-Vis and NMR) features of both types of complexes are in agreement with their corresponding identities.