Hydrogen transfer in photoexcited phenol/ammonia clusters by UV–IR–UV ion dip spectroscopy and ab initio molecular orbital calculations. I. Electronic transitions

Abstract

The electronic spectra of reaction products via photoexcited phenol/ammonia clusters (1:2–5) have been measured by UV-near-IR–UV ion dip spectroscopy. Compared with the electronic spectra of hydrogenated ammonia cluster radicals the reaction products have been proven to be (NH3)n−1NH4 (n=2–5), which are generated by excited-state hydrogen transfer in PhOH–(NH3)n. By comparing the experimental results with ab initio molecular orbital calculations at multireference single and double excitation configuration interaction level, it has been found that the reaction products (NH3)n−1NH4 (for n=3 and 4), contain some isomers.

Ground State Proton Transfer in Phenol–(NH3)n (n ≤ 11) Clusters Studied by Mid-IR Spectroscopy in 3–10 μm Range

“…36 This means that the major intensity in the IR transitions arises from the second solvation shell and does not provide structural information on the solvated structure of the PhOH molecule. Extensively broadened bands are also seen around 3000 cm −1 .…”

Intermolecular proton-transfer in acetic acid clusters induced by vacuum-ultraviolet photoionization

“…Various mass spectrometric and spectroscopic studies have been carried out for clusters in the gas phase to understand the proton-transfer reaction mechanisms upon photoexcitation and photoionization. [7][8][9][10][11][12][13][14][15][16] Excited state intracluster proton-transfer reactions have been found for clusters of aromatic molecules such as phenol, naphtol, 7-azaindole, and 7-hydroxyquinoline. [13][14][15][16] Formation of the proton-transferred structures have also been concluded for solvated phenol and aniline cluster cations.…”

“…[7][8][9][10][11][12][13][14][15][16] Excited state intracluster proton-transfer reactions have been found for clusters of aromatic molecules such as phenol, naphtol, 7-azaindole, and 7-hydroxyquinoline. [13][14][15][16] Formation of the proton-transferred structures have also been concluded for solvated phenol and aniline cluster cations. [17][18][19][20] An important problem related to intermolecular protontransfer in the gas phase is generation of protonated species in ionization processes.…”

Electron–Proton Decoupling in Excited‐State Hydrogen Atom Transfer in the Gas Phase

“…[1] In particular excitedstate hydrogen transfer (ESHT) in aromatic acids,p roposed at the end of 20th century,h as become an important new principle in photochemistry and related fields.F or example, as ignificant number of photoinduced proton-transfer reactions from X À Hb onds have been re-defined as ESHT, including those of phenol (PhOH), [2] indole, [3] tryptophan, [4] aromatic amino acid cations, [5] and many others. [1] In particular excitedstate hydrogen transfer (ESHT) in aromatic acids,p roposed at the end of 20th century,h as become an important new principle in photochemistry and related fields.F or example, as ignificant number of photoinduced proton-transfer reactions from X À Hb onds have been re-defined as ESHT, including those of phenol (PhOH), [2] indole, [3] tryptophan, [4] aromatic amino acid cations, [5] and many others.…”