Rotational spectra and structures of van der Waals dimers of Ar with a series of fluorocarbons: Arsdot;sdot;sdot;CH2CHF, Arsdot;sdot;sdot;CH2CF2, and Arsdot;sdot;sdot;CHFCF2

摘要

Rotational spectra of van der Waals dimers between an argon atom and CH2CHF, CH2CF2, and CHFCF2have been obtained by pulsedhyphen;supersonic nozzle Fourier transform microwave spectroscopy. Analysis of the derived spectroscopic constants shows that the dimers have structures such that for CH2CHF, CH2CF2, and CHFCF2the Ar atom is positioned over the FCCH, FCF, and FCCF atomic chains with Arhyphen;molecular centerhyphen;ofhyphen;mass distances of 3.62 Aring;, 3.51 Aring;, and 3.56 Aring;, and angles between the Arndash;cm axis and molecular planes of 48.2deg;, 72.9deg;, and 60.5deg;, respectively. Structures for the three dimers are also predicted with a simple multisite model which describes the anisotropy of the dispersive interaction; both the Ar acceptor site and the atomndash;atom distances are satisfactorily reproduced.