2ND-HARMONIC GENERATION FROM LANGMUIR-BLODGETT MONOLAYERS OF AMPHIPHILIC RUTHENIUM(II) COMPLEXES - STRUCTURAL CHARACTERIZATION WITH POLARIZATION MEASUREMENTS

Structural characterization for Langmuir-Blodgett (LB) monolayer assem blies of two types of ruthenium(II) complexes were carried out by usin g the technique of surface second harmonic generation (SHG). Amphiphil ic tris(2,2'-bipyridine)-type complexes, RuBipyCnB, and bis(1,10-phena nthroline)(2,2'-bipyridine)-type complexes, RuPhenCnB (n = 16, 18), fo rmed Z-type LB monolayers. The angular dependence of polarized second harmonic lights of these complexes was carefully examined. All complex es had similar hyperpolarizabilities. Average tilt angles of the polar ization axes varied slightly but definitely on going from RuBipyCnB (3 8 +/- 0.6-degrees) to RuPhenCnB (35 +/- 1.3-degrees), which may be asc ribable to structural difference in the chelating ligands of the compl ex. The polarization axes of the complexes were statistically distribu ted as to the azimuthal direction in the substrate surface.