Inelastic neutron scattering spectroscopy has been used to study the rotational dynamics of methyl groups in the p-tert butylcalix [4] arene(1:1)toluene complex. The neutron scattering function shows several lines between 0. 16 and 2.6 meV, and can be satisfactorily reproduced by the single-particle model for rotational tunneling only if the presence of inequivalent sites is assumed, in contrast with the crystallographic determinations. An approach consistent with the room-temperature crystal structure and giving a satisfactory description of the experimental results is obtained by the quantum sine-Gordon model, which describes the dynamics of infinite chains of coupled methyl groups.
A new class of compounds suited to study the torsional dynamics in the quantum regime: the calixarenes / Caciuffo, ROBERTO GIOVANNI MARIA; G., Amoretti; F., Fillaux; Francescangeli, Oriano; S., Melone; M., Prager; F., Ugozzoli. - In: CHEMICAL PHYSICS LETTERS. - ISSN 0009-2614. - 201 (5-6):(1993), pp. 427-432. [10.1016/0009-2614(93)85096-7]
A new class of compounds suited to study the torsional dynamics in the quantum regime: the calixarenes
CACIUFFO, ROBERTO GIOVANNI MARIA;FRANCESCANGELI, ORIANO;
1993-01-01
Abstract
Inelastic neutron scattering spectroscopy has been used to study the rotational dynamics of methyl groups in the p-tert butylcalix [4] arene(1:1)toluene complex. The neutron scattering function shows several lines between 0. 16 and 2.6 meV, and can be satisfactorily reproduced by the single-particle model for rotational tunneling only if the presence of inequivalent sites is assumed, in contrast with the crystallographic determinations. An approach consistent with the room-temperature crystal structure and giving a satisfactory description of the experimental results is obtained by the quantum sine-Gordon model, which describes the dynamics of infinite chains of coupled methyl groups.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
