New nonlinear optical polyurethanes with adjusted subtle structure through Sonogashira coupling reaction

In this paper, four new nonlinear optical (NLO) polyurethanes ( P1 – P4 ) were designed and synthesized, and according to the concept of “suitable isolation group,” the subtle structure of the obtained polymers were modified by the introduction of isolation groups in different sizes to adjust their properties via Sonogashira coupling reaction. All the polymers were well characterized and the second harmonic generation (SHG) experiment results demonstrated that BOP groups were the suitable isolation groups in this system, and the corresponding polymer P2 exhibited a larger d₃₃ value than other polymers. Thus, the obtained results further confirmed our original idea and were consistent with the concept of “suitable isolation group.” Copyright © 2009 John Wiley & Sons, Ltd.