Zero-field splitting of the ground and excited triplet states of 2-naphthylphenylcarbene studied by hole-burning on triplet-triplet fluorescence excitation spectra

✍ Scribed by B. Kozankiewicz; J. Bernard; E. Migirdicyan; M. Orrit; M.S. Platz

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 425 KB
• Volume: 245
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(95)01046-c

✦ Synopsis

Spectral holes were burned in the two main lines of the triplet-triplet 0-0 fluorescence excitation spectrum of 2-naphthylphenylcarbene in n-hexane at 1.8 K. For the line assigned to pseudo-E/trans conformer, the central hole at the frequency of buming light has several narrow components separated by 0.3 + 0.05 and 1.0 + 0.1 GHz and a satellite doublet line on the low energy side, 14.5 + 0.5 and 15.5 -t-0.5 GHz away. For the line assigned to the pseudo-Z/cis conformer, the central hole is accompanied by holes burned on the low energy side, 0.8_ 0.1, 5.2 + 0.1, 11.9 + 0.1 and 16.2-I-0.1 GHz away. The hole-burning pattern is explained by a model taking into account the zero-field splitting (ZFS) of the ground T O and excited T~ triplet states as well as the selectivity of excitation relaxation by the intersystem crossing channel. Analysis provides information about the ZFS parameters of the T l state. For the pseudo-E/trans 2-NPC they are: D O = 0.47 + 0.02 cm -~. Eo = 0.017 + 0.003 cm -l, D l =0.038+0.