Hydrogen-bond equilibria and lifetimes in a monohydroxy alcohol.
Dielectric loss spectra covering 13 decades in frequency were collected for 2-ethyl-1-hexanol, a monohydroxy alcohol that exhibits a prominent Debye-like relaxation, typical for several classes of hydrogen-bonded liquids. The thermal variation of the dielectric absorption amplitude agrees well with that of the hydrogen-bond equilibrium population, experimentally mapped out using near infrared (NIR) and nuclear magnetic resonance (NMR) measurements. Despite this agreement, temperature-jump NIR spectroscopy reveals that the hydrogen-bond switching rate does not define the frequency position of the prominent absorption peak. This contrasts with widespread notions and models based thereon, but is consistent with a recent approach.
Fakultät für Physik, Technische Universität Dortmund, 44221 Dortmund, Germany.
C
C
Gainaru
S
S
Kastner
F
F
Mayr
P
P
Lunkenheimer
S
S
Schildmann
H J
HJ
Weber
W
W
Hiller
A
A
Loidl
R
R
Böhmer