2ND-ORDER NONLINEAR-OPTICAL LANGMUIR-BLODGETT-FILMS BASED ON A SERIES OF AZO RARE-EARTH COORDINATION-COMPOUNDS

A series of novel azo dyes composed of a lanthanide complex anion and an azo cation, in which strongly electron-donating (dihexadecylamino)phenyl and electron-accepting pyridinium groups are separated by an azo group, was designed as second-order nonlinear optical Langmuir-Blodgett (LB) film materials. The compounds are of good film-forming properties. The values of second-order molecular hyperpolarizability beta were determined to be (1.20-3.03) x 10(-27) esu, comparable to the largest value known for azo LB materials. The compounds we studied may be attractive in the application in future optical devices.