Spectral shifts and structures of phenol⋯Arnclusters

Abstract

A laser spectroscopic investigation of phenol⋯Ar_n (n = 1–6) clusters in the first electronically excited state (S₁) and the cationic ground state (D₀) is reported. Resonance enhanced two-photon ionisation (R2PI) spectra have been recorded for the investigation of the S₁ state. The origins of S₁ ← S₀ (S₁0⁰) transition of phenol⋯Ar_n (n = 1, 2,4–6) are all red shifted compared to the S₁0⁰ state of the monomer by 33 cm⁻¹, 67 cm⁻¹, 10 cm⁻¹, 20 cm⁻¹, 44 cm⁻¹, respectively. However, the origin of the phenol⋯Ar₃ cluster is blue shifted by 25 cm⁻¹. For the investigation of the ionic ground state photoionization efficiency (PIE) and mass-analyzed-threshold ionization (MATI) spectroscopy have been applied. The spectra of phenol⋯Ar₃ and phenol⋯Ar₄ yield values for the ionization energy (IE) of 68 077 ± 15 cm⁻¹ and 67 948 ± 15 cm⁻¹. With the combination of theoretical methods and R2PI, PIE and MATI spectroscopy, the major species present have been positively identified.