The (3)A(2)(npi*) --> (1)A(1) X (T-1 --> S-0) phosphorescence excitation spectrum of jet-cooled xanthione was investigated in the region 14 920-17 600 cm(-1). The structure observed is shown to be due to the T-1 <-- S-0 absorption and an assignment in terms of the vibronic structure of that band is proposed. A previous assignment of the S, So origin is considered in detail and the transition involved is shown to be most probably due to absorption of a vibronic triplet state T-1z,T-nu7. An alternative but tentative assignment of the S-1,S-0 <-- S-0,S-0 transition is suggested. Comparison is made with previous spectroscopic and theoretical work on the molecule and its congeners, 4H-pyran-4-thione and 4H-1-benzopyran-4-thione. (C) 2002 Elsevier Science (USA).The (3)A(2)(npi*) --> (1)A(1) X (T-1 --> S-0) phosphorescence excitation spectrum of jet-cooled xanthione was investigated in the region 14 920-17 600 cm(-1). The structure observed is shown to be due to the T-1 <-- S-0 absorption and an assignment in terms of the vibronic structure of that band is proposed. A previous assignment of the S, So origin is considered in detail and the transition involved is shown to be most probably due to absorption of a vibronic triplet state T-1z,T-nu7. An alternative but tentative assignment of the S-1,S-0 <-- S-0,S-0 transition is suggested. Comparison is made with previous spectroscopic and theoretical work on the molecule and its congeners, 4H-pyran-4-thione and 4H-1-benzopyran-4-thione. (C) 2002 Elsevier Science (USA).