Tetrahedra from Aryleneethenylenes–From small Molecules to Luminescent Glasses

Abstract

The fourfold Horner olefination of tetraphenylmethane or–silane with four p-methylphosphonate groups and a variety of aromatic aldehydes with donor groups or extended conjugated systems results in the formation of tetrahedra from four chromophores connected via a central atom. Electronic spectra in solution reveal an electronic interaction between the π-systems. In the solid state, the emission of compounds with a dense packing is nearly identical to the solution spectra, more open structures show significant red shifts. The emission of scaffolds with 1-styrylpyrene chromophores is nearly completely quenched. Most of these tetrahedra are thermally stable up to 420°C. Depending on the diameter of the scaffold, glass transitions occur between 99°C and 169°C.