Pyranylidenemethyl- and Thiopyranylidenemethyl-substituted Furans, Thiophenes, and<i>N</i>-Methylpyrroles as Precursors of Organic Metals and Third-order Nonlinear Optical Materials
The title heteroaromatics have been synthesized by Wittig-Hornor reactions of the appropriate heterocyclic dialdehydes with diethyl pyranyl- and thiopyranyl-phosphonate. Cyclic voltammetry indicated their strong π-donor abilities, and some TCNQ complexes showed high electrical conductivities. They were also found to have large third-order nonlinear optical susceptibilities.