Synthesis, crystal structures and yeast RNA-binding properties of copper(II) and nickel(II) complexes with a bidentate Schiff base

Abstract

Trans-CuL 2 and cis-NiL 2 (L = 1-((furan-2-yl)methylene)-4-phenylthiosemicarbazide) were synthesized and characterized by physico-chemical and spectroscopic methods. Their X-ray crystal structures were determined. The complexes contain the same bidentate Schiff base ligand, but with different cis-NiN 2 S 2 and trans-CuN 2 S 2 square-planar coordination geometries. Three-dimensional supramolecular networks were formed through ''face to face'' p-p conjugated systems between phenyl and furan rings. The interactions with yeast RNA (yRNA) were investigated by UV spectra and electrochemical methods, which showed that the complexes intercalated into yRNA. The bonding of trans-CuL 2 to yRNA is the stronger of the two, suggesting that the trans geometry is more favorable for interaction with RNA.