Synthesis and photobehaviour of donor-π-acceptor conjugated arylacetylenes

Two series of soluble and thermally stable asymmetric arylacetylene derivatives bearing a fluorene (Fl-Xs) or an anthracene (An-Xs) core unit and end-substituted with different electronically active groups (X = NO2, CN, CHO and OR) were synthesized and characterized. The spectral and photophysical behaviour of these compounds was studied in two solvents of different polarity to evaluate them as candidates for the role of active materials in optoelectronic devices. The presence of intramolecular charge transfer states, strongly stabilized in the polar solvent, was found mainly in the nitro-anthryl and fluorenyl-derivatives. A complete picture of the excited states nature and their deactivation channels was also achieved by semiempirical quantum-mechanical calculations.