Synthesis and non-linear optical properties of (η 5-pentaphenylcyclopentadienyl)dicarbonylruthenium(II) σ-alkenyl complexes

Abstract

The complexes [Ru{( Z)-HC CHPh}(CO) 2(η 5-C 5Ph 5)] ( 1) and [Ru{( Z)-HC CHC 6H 4NO 2}(CO) 2(η 5-C 5Ph 5)] ( 2) have been synthesized and their identity confirmed by single-crystal X-ray diffraction studies. Reaction of 2 with PMe 2Ph and Me 3NO in tetrahydrofuran afforded [Ru{( Z)-HC CHC 6H 4NO 2}(CO)(PMe 2Ph)(η 5-C 5Ph 5)] ( 3). Cyclic voltammetry confirms the expected increase in ease of oxidation on proceeding from 2 to 1 and from 2 to 3. Hyper-Rayleigh scattering studies at 1064 nm reveal a dramatic increase in quadratic non-linearity on co-ligand replacement of CO by PMe 2Ph, in proceeding from 2 to 3. Z-scan studies at 800 nm are consistent with significant contribution from two-photon states, and with an increase in γ real on co-ligand replacement of CO by PMe 2Ph in proceeding from 2 to 3.