New one- and two-dimensional 4H-pyranylidene NLO-phores
Résumé
Dipolar, V-shaped compounds derived from 4H-pyranylidene-linked acceptors have been synthesized, and their linear and nonlinear optical properties (displaying μβ values up to 3000 × 10−48 esu) have been compared to those of analogous one-dimensional derivatives. The pyranylidene ring behaves strictly as a spacer, and not as a donor group.