Influence of temperature and pressure on narrow-band fluorescence of 1,8-diphenyloctatetraene in solid crystalline solutions

Forbidden 2(1)A(g)-1(1)A(g) fluorescence of 1,8-diphenyloctatetraene has be en recorded in n-tetradecane and aromatic crystal hosts (naphthalene, biben zyl, p-quaterphenyl) in the temperature interval from 5 to 50 K and under t he He gas pressure up to 200 bar. Both the pressure and the temperature-ind uced shifts of lines have opposite signs in Shpolskii and aromatic matrices . The pressure and temperature shifts as well as the increase of S-1-S-0 on e-photon transition probability in aromatic crystals were rationalised in t erms of the change in S-2-S-1 splitting that is smaller in aromatic hosts a s compared to n-alkanes. (C) 2000 Elsevier Science B.V. All rights reserved .