NEW NLO STILBENE DERIVATIVES BEARING PHOSPHONATE ESTER ELECTRON-WITHDRAWING GROUPS

The synthesis and characterization of a new class of electron donor-ac ceptor substituted stilbenes bearing a phosphonate ester as the electr on-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 coeff icient (r33), it was demonstrated that the phosphonate ester group is effective as an electron-withdrawing group for stilbene-based second-o rder NLO materials. (C) 1997 Elsevier Science Ltd.