Rovibronic signatures of molecular aggregation in the gas phase: subtle homochirality trends in the dimer, trimer and tetramer of benzyl alcohol

Abstract

Molecular aggregation is of paramount importance in many chemical processes, including those in living beings. Thus, characterization of the intermolecular interactions is an important step on its understanding. We describe...

The evolution towards cyclic structures in the aggregation of aromatic alcohols: the dimer, trimer and tetramer of 2-phenylethanol

“…10). Thus, while a single isomer was found for PhOH dimer, 29,58–60 at least three isomers were detected for BzOH dimer (hom-O g π-I, het-O g π-II and het-ππ-III) 31 and PhEthOH dimer. The dimer species observed for PhEtOH share a common interaction pattern built on the O–H⋯O and O–H⋯π hydrogen bonds and the most stable gauche monomer conformation.…”

“…Two trimers and two tetramers have been found for BzOH using laser spectroscopy. However, previous FTIR and Raman spectroscopy studies 31 also demonstrated that the broad absorptions in the IR/UV spectra may hide the contribution from multiple isomers. This may also be the case for PhEtOH, where we also detected at least two trimers and two tetramers.…”

“…However, the aggregation process locks the hydroxyl conformations, resulting in the homo- and hetero-chiral series of aggregates, as described in previous publications. 31,48…”

“…25,26 For aliphatic compounds, we developed a new laser technique that combines ns and fs laser sources to record mass-resolved IR spectra of molecules without chromophore. 27,28 The self-aggregation of the simple aromatic alcohols phenol (PhOH), 29,30 benzyl alcohol (BzOH) 31 and furfuryl alcohol, 25 has recently been compared with the thiol and amine derivatives thiophenol, 26 benzyl mercaptan 32 and aniline. 33 The aromatic alcohols present interesting connections between intramolecular interactions and conformational properties, which become more complex with each additional methylene group.…”

Torsional chirality and molecular recognition: the homo and heterochiral dimers of thenyl and furfuryl alcohol

“…This study also provides an accurate description of the intermolecular forces in the dimerization process, characterized by a cooperative behavior of two hydrogen bonds including interactions to the ring heteroatom or the p ring. 46,47,55,60 Furthermore, the comparison between the furfuryl and thenyl compounds explores the different role of the hydrogen bond involving sulfur, which in the thenyl compounds have less priority that the interaction to the p ring system. The molecular description of the two alcohol dimers, while structurally similar to the monohydrates, offers a completely different combination of dispersion effects, calling for adequate dispersion-corrected quantum mechanical models.…”