Rotational dynamics of Li+ ions encapsulated in C60 cages at low temperatures. Issue 46 (14th November 2016)

• Record Type: Journal Article
• Authors: Suzuki, Hal; Ishida, Misaki; Yamashita, Masatsugu; Otani, Chiko; Kawachi, Kazuhiko; Kasama, Yasuhiko; Kwon, Eunsang
• Is Part Of: Physical chemistry chemical physics. Volume 18:Issue 46(2016)
• Page Start: 31384
• Page End: 31387
• Publication Date: 2016-11-14
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c6cp06949e
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : Rotational motions of Li + ions encapsulated in C60 cages gradually change into librational ones below 120 K. Abstract : Li + ions encapsulated in fullerene C60 cages (Li + @C60 ) are expected to be suitable as molecular switches that respond to local electric fields. In this study, the rotational dynamics of Li + ions in C60 cages at low temperatures are experimentally revealed for the first time using terahertz absorption spectroscopy. In crystalline [Li + @C60 ](PF6 − ), the Li + ion rotates in the carbon cage even at 150 K. The rotational mode gradually changes into a librational mode below 120 K, which is associated with the localization of Li + ions due to the electrostatic interactions with its screening image charge on the C60 cage as well as with the neighboring Li + @C60 and PF6 − ions. A simple rotational/librational energy scheme for the Li + ions successfully explains the spectroscopic results, and the potential of Li + @C60 as a molecular switch is discussed based on the energy scheme.