Ian R. Whittall

Organometallic materials for non-linear optics. Second harmonic generation by (aryldiazovinylidene) ruthenium complexes; X-ray structure of [Ru(CCPhNNC6H4OMe-4)(PPh3)2(η-C5H5)][BF4]·CH2Cl2

A series of (aryldiazovinylidene)ruthenium complex salts of general formula [Ru(CCPhNNAr)(PPh3)2(η-C5H5)][X] has been synthesized. The Kurtz method was used to investigate their effectiveness in second harmonic generation, and revealed efficiencies up to that of a urea reference standard. An X-ray structural study of the complex exhibiting the strongest response, [Ru(CCPhNNC6H4OMe-4)(PPh3)2(η-C5H5)][BF4]·CH2Cl2 revealed that the material packs centrosymmetrically, suggesting that the observed moderate bulk χ(2) responses arise from large molecular β responses and some crystal mispacking.

Novel Organometallic Compounds for Nonlinear Optics

Hyper-Rayleigh scattering is used to investigate the nonlinear optical properties of novel metal (ruthenium, nickel and gold) σ-arylacetylide complexes. The influence of the organometallic donor group and conjugating bridge on the quadratic hyperpolarizability is studied. For all organic ligands, the addition of the metal (donor) group is shown to increase the static hyperpolarizability by a factor of 2, 4 and 7 for gold, nickel and ruthenium complexes, respectively. Moreover, replacement of phenyl with a heterocyclic ring is demonstrated to enlarge the hyperpolarizability in the case of gold and ruthenium compounds.