The Synthesis and the Electronic Spectra of 1, 1′-Dianthrylpoly-ynes

The synthesis of 1, 1′-dianthryldi- and tetra-acetylenes has been reported previously by the present authors. Now, 1, 1′-dianthryltri-, penta- and hexa-acetylenes have been synthesized in order to complete the series of 1, 1′-dianthrylpoly-ynes. It is well known that the square of the wavelength of the longest absorption maxima, λmax in the electronic spectra of some series of poly-enes and poly-ynes varies linearly with the number of the multiple bonds, n(λmax2∞n). It was anticipated that the dianthrylpoly-ynes would exhibit analogous spectral behavior. Unexpectedly, however, it was observed that the λmax of the dianthrylpolyacetylenes varied linearly with the square of the number of the triple bonds, n(λmax∞n2).