New NLO stilbene derivatives bearing phosphonate ester electron-withdrawing groups

The synthesis and characterization of a new class of electron donor-acceptor substituted stilbenes bearing a phosphonate ester as the electron-withdrawing functionality is described. Phosphorylation of aromatic rings was accomplished using Ni-catalyzed Arbuzov reactions, while Pd-catalyzed Heck-type coupling reactions were employed to construct the stilbene derivatives. Through determination of an electro-optic coefficient (r33), it was demonstrated that the phosphonate ester group is effective as an electron-withdrawing group for stilbene-based second-order NLO materials. (C) 1997 Elsevier Science Ltd.