Infrared-depletion spectroscopy study on hydrogen-bonded fluorobenzene–methanol clusters

Abstract

Infrared-depletion spectroscopy, a double resonance method combining infrared- with resonant two-photon ionization (R2PI)-spectroscopy has been applied to mixed molecular aggregates of fluorobenzene⋅(methanol)n (Fb⋅MeOH) with n⩽4. From the IR spectra in the region of the OH stretching vibration of methanol it can be shown that the solvent moiety forms subclusters on one side of the aromatic ring. For Fb⋅(MeOH)3 the methanol trimer exhibits a linear as well as a cyclic structure. The different shifts of the UV bands of these two isomeric clusters reveal the diverse character of the hydrogen bonds involved in their formation. Furthermore it can be shown that for both isomeric forms the product anisole+ is formed in equal quantities by an intracluster SN2 reaction following the photoionization of the chromophore. Whereas for Fb⋅(MeOH)2 this reaction is in competition with evaporative fragmentation it is the dominant reaction channel for the Fb⋅(MeOH)3 cluster.

Interaction of the water dimer with π-systems: A theoretical investigation of structures, energies, and vibrational frequencies

“…[3][4][5][6][7][8][9][10] As a result, experimental investigations have been carried out on clusters ranging from the simple water to the more complex aromatic clusters. 7,[11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] On the other hand, high level theoretical studies have been limited to the simpler water or phenol water clusters ͑which are bound by typical H-bonding interactions͒, and more recently the benzene water clusters. 14,15,[31][32][33][34][35][36][37][38][39][40][41][42][43][44] The problems of carrying out theoretical investigations on clusters containing more complex aromatic systems are amply illustrated by our recent studies of various interactions involving complex aromatic systems.…”

Multi-spectroscopic and theoretical analyses on the diphenyl ether–tert-butyl alcohol complex in the electronic ground and electronically excited state

“…In a further study by Fujii and coworkers, 20 intracluster nucleophilic substitution reactions in fluorobenzene-methanol clusters were investigated, which have also been studied in the S 0 state. 21 In the S 1 state, 20 evidence was found for a weakened hydrogen bond, indicated by a blueshifted OH-stretching frequency compared to the S 0 state. In a purely theoretical work, Zhao et al 22 predicted a red-shifted OH-stretching frequency in the S 1 compared to the S 0 state of the fluorenonemethanol complex, obtained by time-dependent density functional theory (TD-DFT) calculations.…”

The World of Non-Covalent Interactions: 2006

“…Most frequently, an H-bond is of the X-H...Y type, where X is the electronegative element and Y is the contact with excess of electrons. H-bonds with X, Y = F, O and N are the most frequent and most extensively studied [166][167][168] , though X-H...π hydrogen bonds (for X = O and C) have also been observed [169][170][171][172][173][174][175][176] .…”