HOLE-BURNING STUDIES ON TRIPLET-TRIPLET FLUORESCENCE EXCITATION SPECTRUM OF 2-NAPHTHYLPHENYLCARBENE

Spectral holes were burned on the triplet-triplet 0-0 fluorescence exc itation lines of main conformers of 2-naphthylphenylcarbene in n-hexan e and n-heptane at 1.8 K. The central holes, at a frequency of laser b urning light have usually several accompanying satellite holes in a ra nge of 1.5 GHz around and deep holes on the low energy side, 14.5 - 16 .5 GHz away. Such a pattern of holes reflects the zero field splitting of the ground T-0 and first excited T-1 triplet states and the fact t hat an energy relaxation by the intersystem crossing channel is highly selective.