Photophysical properties of symmetrically substituted diarylacetylenes and diarylbuta-1,3-diynes.

A series of symmetrically substituted diarylacetylenes and diaryl-1,3-butadiynes were prepared and studied with an emphasis on their spectral and photophysical properties. The photophysical characteristics of these compounds were studied in relation to their structures and the influence of solvent or temperature. The observed spectral and photophysical properties are explained using potential energy maps of the ground and excited states obtained from density functional theory calculations. The structure-property relationships of all of the compounds are discussed and compared with the appropriate diphenylacetylene and diphenyl-1,3-butadiyne derivatives.