Synthesis and structural characterization of a new polysiloxane with second‐order nonlinear optical effect

A new polysiloxane ( P2 ), with a high density of the indole‐based chromophore and carbazolyl side groups, was prepared. Thus a polysiloxane ( P1 ), with indole and carbazolyl groups as side chains, was first synthesized through a hydrosilylation reaction, and then the post‐azo coupling of p ‐nitrobenzenediazonium fluoroborate toward the indole ring gave the mulifunctional indole‐based chromophore‐functionalized polysiloxane ( P2 ). Molecular structural characterization for the polymers was determined by 1 H‐NMR, IR, and UV–visible spectra, gel permeation chromatography, and differential scanning calorimetry. The polymers were easily soluble in common organic solvents. The poled film of P2 revealed a resonant d 33 value of 27 pm/V by second‐harmonic generation measurements. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 769–774, 2004