Synthesis and electrochemical studies of η5-monocyclopentadienylruthenium(II) complexes with substituted thiophene nitrile ligands. Crystal structure of [Ru(η5-C5H5)(dppe)(NC{SC4H2}2NO2)][PF6]

A systematic series of η5-monocyclopentadienylruthenium(II) complexes with substituted thiophene nitrile ligands of general formula [Ru(η5-C5H5)(P_P)(NC{SC4H2}nNO2)][PF6] (P_P = dppe, (+)-diop; n = 1–3) has been synthesized and characterized. Spectroscopic and electrochemical data were used in order to get an insight on the molecular nonlinear optical properties of these complexes when compared to those found for the reported thiophene iron(II) and p-benzonitrile or 1,2-di-(2-thienyl)-ethene derived iron(II)/ruthenium(II) related complexes. The compound [Ru(η5-C5H5)(dppe)(NC{SC4H2}2NO2)][PF6] was also characterized by X-ray diffraction. The solid state nonlinear optical properties of the chiral compounds were also evaluated by Kurtz powder technique with a Nd:YAG laser emitting at 1064 nm.