Rotational mobility of guest molecules in o-terphenyl below T(g)

S Yu Grebenkin; B V Bol'shakov

doi:10.1021/jp057487o

Rotational mobility of guest molecules in o-terphenyl below T(g)

J Phys Chem B. 2006 May 4;110(17):8582-6. doi: 10.1021/jp057487o.

Authors

S Yu Grebenkin¹, B V Bol'shakov

Affiliation

¹ Institute of Chemical Kinetics and Combustion, Novosibirsk 630090, Russian Federation. grebenk@ns.kinetics.nsc.ru

PMID: 16640410
DOI: 10.1021/jp057487o

Abstract

An optical anisotropy decay technique for measuring probe rotational times in glassy materials is presented. Rotational times from 10(1.4) to 10(5) s have been obtained for a molecule of 1-naphthyl-azomethoxybenzene (NAMB) in o-terphenyl (OTP) over a temperature range from T(g) +3.5 to T(g) -16.5 K. The rotational diffusion follows the temperature dependence of Debye-Stokes-Einstein down to T(g) -4 K with an activation energy of 320 +/- 30 kJ/mol. Below T(g) -9 K, the temperature dependence of rotation mobility was found to be much weaker with an activation energy of 70 +/- 15 kJ/mol.