Rotational correlation time
Rotational correlation time is the time it takes for a molecule to rotate one radian, on average. Rotational correlation times are in the order of picoseconds, for example 1.7 picoseconds for water[1] or in the tens to hundreds range for small organic molecules.[2] Rotational correlation times are employed in the measurement of microviscosity (viscosity at the molecular level) and in protein characterization.
Rotational correlation times may be measured by rotational (microwave) or dielectric spectroscopy. Rotational correlation times of probe molecules in media have been measured by fluorescence lifetime or for radicals, from the linewidths of electron spin resonances.
References
This article is issued from Wikipedia - version of the 11/28/2013. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.