Hydrogen-bond equilibria and life times in a supercooled monohydroxy alcohol

Authors :: Gainaru, C.
Kastner, S.
Mayr, F.
Lunkenheimer, P.
Schildmann, S.
Weber, H. J.
Hiller, W.
Loidl, A.
Böhmer, R.
Source :: Phys. Rev. Lett. 107, 118304 (2011)
Publication Year :: 2011
Abstract: 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.<br />Comment: 4 pages, 4 figures