Photoisomerization in an analogous set of ruthenium sulfoxide complexes

Complexes of the type [Ru(bpy)2(OSOBnR)](PF6) where bpy is 2,2′-bipyridine and OSOBnR is a 4-substituted benzylsulfinylbenzoate with R = NO2, F, Cl, H, CH3, CF3 and OCH3, have been prepared and investigated by 1H NMR spectroscopy, cyclic voltammetry and UV-vis spectroscopy. Despite the distance of the R group from ruthenium, the Ru3+/2+ reduction potential and charge transfer absorption maximum vary predictably with the electron withdrawing nature of the group.