H-bonded network rearrangements in the S0, S1 and D0 states of neutral and cationic p-cresol(H2O)(NH3) complexes

Abstract

The H-bonded network rearrangements in the S(0), S(1) and D(0) states of the neutral and cationic p-CreOH(H(2)O)(NH(3)) complexes were studied experimentally by means of (1 + 1)/(1 + 1') REMPI (Resonantly Enhanced MultiPhoton Ionization) and time resolved LIF (Laser Induced Fluorescence) spectroscopies combined with DFT (Density Functional Theory) calculations at the B3LYP/6-311G++(d,p) level. A comparison of the rearrangement process of the H-bonded network in the three states is given. Two cyclic H-bonded isomers were found on the S(0) potential energy surface and the results indicate that the rearrangement in this state is unlikely at the temperature of the supersonic expansion due to the presence of a high-energy barrier (7503 cm(-1)). On the other hand, the re-determination of the S(1) excited state lifetimes confirms that neither the H-bonded rearrangement nor the excited state hydrogen transfer (ESHT) reaction takes place in the S(1) state at the excitation energies of this work. Thus, it is concluded that the absorption of the second photon to reach the D(0) state takes place from the S(1) state of the cyclic-(OH-OH(2)-NH(3)) isomer. A preferential evaporation of H(2)O upon vertical ionization of the cyclic-(OH-OH(2)-NH(3)) isomer is observed which is consistent with a statistical redistribution of the internal energy. Nevertheless, our theoretical calculations suggest that initial excitation of the H-bonded network rearrangement modes may also play a role to leave the H(2)O molecule as a terminal moiety in a chain-(OH-NH(3)-OH(2))(+) isomer. The reaction pathway for the solvent rearrangement involves a double proton transfer process with a very low energy barrier (575 cm(-1)) that is overcome at the vertical ionization energy of the complex.

Interaction of Aromatic Compounds with Xenon: Spectroscopic and Computational Characterization for the Cases of p-Cresol and Toluene

“…Other small ACs, such as toluene and p- cresol, have also been studied with respect to intermolecular interactions although in a lesser extent than phenol. A number of complexes of these molecules have been investigated in supersonic jets. − The effect of van der Waals interactions on the dynamics of toluene and p -cresol in an excited state has been investigated. − …”

Rearrangement of aniline(H2O)n (n = 0–12) clusters upon photoionization and their excited state properties: Density functional theory and time‐dependent density functional theory study

“…23 Furthermore, in its cationic electronic ground state (D 0 ), aniline ion is planar according to the vibrational spectroscopic analysis. 24 Cationic clusters produced upon photoionization undergo drastic rearrangement in their structures compared to the corresponding neutrals [25][26][27][28][29][30] mainly due to the positive charge produced.…”

Ultrafast Protonation of an Amide: Photoionization-Induced Proton Transfer in Phenol-Dimethylformamide Complex Cation

“…Our goal is to elucidate how the system evolves in the ionic collision complex from an initial nonproton-transferred (non-PT) to a final proton-transferred (PT) configuration, before the complex exits for the product channel. In spite of recent research interests on photoionization-induced PT in molecular complexes, − ultrafast time-resolved measurements of such reactions are still scarce. , …”