Abstract
The Fourier transform IR vibrational spectra of amino-ethanol (AE) and its dimer have been recorded at room temperature and under jet-cooled conditions over the far and mid infrared ranges (50-4000 cm-1) using the White-type cell and the supersonic jet of the Jet-AILES apparatus at the synchrotron facility SOLEIL. Assignment of the monomer experimental frequencies has been derived from anharmonic frequencies calculated at a hybrid CCSD(T)-F12/MP2 level. Various thermodynamical effects in the supersonic expansion conditions including molar dilution of AE and nature of carrier gas have been used to promote or not the formation of dimers. Four vibrational modes of the observed dimer have been unambiguously assigned using mode-specific scaling factors deduced from the ratio between experimental and computed frequencies for the monomer. The most stable g'Gg' monomer undergoes strong deformation upon dimerization, leading to a homochiral head to head dimer involving two strong hydrogen bonds.
Highlights
Hydrogen bonding plays a major role in defining the organization of matter, at both molecular and supramolecular levels, with effects ranging from the structuration of liquids to the shape of biomolecules.1 Of special interest is the intramolecular hydrogen bond, in which the donor and acceptor parts belong to the same entity
Jet-cooled spectra were recorded using the Jet-AILES apparatus, already described in detail in previous studies, and coupled to the high resolution Bruker IFS 125 Fourier Transform IR (FTIR) spectrometer implemented on the AILES beamline at the synchrotron facility SOLEIL.24
An expansion of helium seeded with AE was used first to avoid cluster formation
Summary
Hydrogen bonding plays a major role in defining the organization of matter, at both molecular and supramolecular levels, with effects ranging from the structuration of liquids to the shape of biomolecules. Of special interest is the intramolecular hydrogen bond, in which the donor and acceptor parts belong to the same entity. In larger systems as well, the presence or absence of an intramolecular OH· · · N hydrogen bond has important consequences in biological processes, which has prompted the study of numerous neurotransmitters based on the amino alcohol motif in the gas phase.. We revisit here the vibrational spectroscopy of AE and its dimer in the hydride stretch, mid infrared (MIR), and far infrared (FIR) regions, by means of the Jet-AILES apparatus, installed on the infrared beamline AILES at the synchrotron facility SOLEIL.26–28 This experimental setup combines a continuous supersonic expansion with a pumping capacity adapted to high molecular flows and a high resolution Fourier Transform IR (FTIR) spectrometer. Vibrational signatures of the AE dimer are investigated and compared to ab initio frequency calculations
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
