A Hole-Burning Study of the Zero-Field Splitting of the Triplet Ground and Excited States of 2,2-Dinaphthylcarbene in n-Heptane and n-Hexane at 1.7 K

摘要

Spectral holes were burned within the inhomogeneous 0,0 fluorescence excitation lines of the T_0->T_1 transition of 2,2-dinaphthylcarbene (2,2-DNC) in n-heptane at 1.7 K. The spectrum of holes, attributed to the Z/cis conformer of 2,2-DNA, was interpreted with a model taking into account the zero-field splitting (zfs) of both triplet states contributing to the transition, enforced C_2v symmetry, and the dominance of internal conversion in the relaxation of the excited T_1 state. Under enforced high symmetry, the number of possible electronic transitions between different spin sublevels of the ground T_0 and excited T_1 states is reduced and the analysis of spectral position of holes can only proide the differences between the zfs parameters: D_0-D_1=0.558+-0.001 cm~(-1) and E_0-E_1=0.0138+-0.001 cm~(-1).