Synthesis, characterization, crystal structure, and DNA interaction of tin complexes containing pyridyl ligands

Abstract

The reactions of 4′-aryl-2,2′:6′,2′′-terpyridines (aryl = phenyl, p-tolyl, p-anisyl, p-chlorophenyl, 4-pyridyl) and 3-phenyl-1,5-bis(2-pyridyl)-1,5-pentanedione with dimethyltin(IV) dichloride and tin(II) dichloride have been investigated. The resulting products have been fully characterized by elemental analysis and multinuclear (1H, 13C, 119Sn) NMR spectroscopy and X-ray crystal structure determination in the case of [SnCl2(pytpy)] (pytpy = 4′-(4-pyridyl)-2,2′:6′,2′′-terpyridine). The crystal structure of [SnCl2(pytpy)] reveals that tin(II) is pentacoordinated in a highly distorted square pyramidal geometry. Moreover, the binding interaction of complex [SnCl2(pytpy)] with calf thymus-DNA (ct-DNA) has been investigated using UV–Vis spectroscopy. Data reveals that the groove binding is a mode of the interaction with a moderate binding constant of 7.2 (±0.2) × 103 M−1.