The influence of large-amplitude librational motion on the hydrogen bond energy for alcohol-water complexes
Författare
Summary, in English
The far-infrared absorption spectra have been recorded for hydrogen-bonded complexes of water with methanol and t-butanol embedded in cryogenic neon matrices at 2.8 K. The partial isotopic substitution of individual subunits enabled by a dual inlet deposition procedure provides for the first time unambiguous assignments of the intermolecular high-frequency out-of-plane and low-frequency in-plane donor OH librational modes for mixed alcohol-water complexes. The vibrational assignments confirm directly that water acts as the hydrogen bond donor in the most stable mixed complexes and the tertiary alcohol is a superior hydrogen bond acceptor. The class of large-amplitude donor OH librational motion is shown to account for up to 5.1 kJ mol(-1) of the destabilizing change of vibrational zero-point energy upon intermolecular OH center dot center dot center dot O hydrogen bond formation. The experimental findings are supported by complementary electronic structure calculations at the CCSD(T)-F12/aug-cc-pVTZ level of theory.
Avdelning/ar
Publiceringsår
2015
Språk
Engelska
Sidor
23761-23769
Publikation/Tidskrift/Serie
Physical Chemistry Chemical Physics
Volym
17
Issue
37
Dokumenttyp
Artikel i tidskrift
Förlag
Royal Society of Chemistry
Ämne
- Physical Chemistry
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 1463-9084