ZERO-FIELD SPLITTING OF THE T-0 AND T-1 STATES OF 2-NAPHTHYLPHENYLCARBENE FROM HOLE-BURNING STUDIES OF TRIPLET-TRIPLET TRANSITION

Spectral holes have been burned on the 0,0 fluorescence excitation (T- 0-->T-1) line of 2-naphthylphenylcarbene in n-hexane at 1.8 K. A compl icated spectrum of holes reflects zero-field splitting of both the tri plet states, T-0 and T-1, and provides a way to estimate their splitti ng parameters D-0, E(0), D-1 and E(1). Comparison of the real hole bur ning spectrum with the simulated one suggests possibility of a distrib ution of burning yields and/or a distribution of homogeneous linewidth s of 2-naphthylphenylcarbene molecules located in different sites of a Shpol'skii matrix.