High-resolution UV spectroscopy of the chiral molecule 1-phenylethanol

The rotationally resolved excitation spectrum of the S₁ ← S₀ electronic transition of the chiral molecule 1-phenylethanol is measured <i>via</i> laser-induced fluorescence detection in a cold, seeded molecular beam. The rotational constants and structure of the S₁ state are determined by fitting 419 spectral lines. The transition dipole moment is found to have predominant projections along the <i>b</i> and <i>a</i> inertial axes with only a small contribution along the <i>c</i>-axis, in agreement with <i>ab initio</i> calculations. Using two-color (1 + 1') resonance-enhanced multiphoton ionization the S₁ excited state lifetime is determined as 70 ± 18 ns.