Electronic spectra of jet‐cooled isopropyltropolones in the S1–S0 region. Proton tunneling in the S1 state

摘要: Laser fluorescence excitation spectra and dispersed of jet‐cooled 3‐, 4‐, 5‐isopropyltropolone in the S1–S0 region have been measured to investigate effect unsymmetrical symmetrical substitution an isopropyl group on proton tunneling. The 0++ 0−+ transitions identified 3‐isopropyltropolone its −OD derivative. tunneling doublet splittings S1 state determined be 58 14 cm−1 for normal deuterated species, respectively. increase splitting compared with that tropolone suggests induces asymmetry double‐minimum potential well. In contrast spectrum 3‐isopropyltropolone, no 0−− detected 4‐ 5‐isopropyltropolone. nonobservation these is likely due substantial potential‐energy barrier th...