Association of Haloforms in Condensed and Gas Phases. Ir Spectroscopy and Dft Calculations

Abstract

Fourier-transform infrared (FTIR) spectra are recorded for the haloforms of fluorine, chlorine, and bromine atoms in gas and liquid phases, as well as for their low-temperature films at 20–200 K. The molecules of these compounds are shown to be connected by hydrogen bonds associated with the transfer of a hydrogen atom. According to ab initio DFT calculations, chloroform demonstrates two types of associated structures, one with the chlorine atom and the other with the central carbon atom binding as the proton acceptor in the intermolecular interaction. At the same time, calculations predict only one form of bonding for two other haloforms, namely, between the hydrogen atom and the fluorine atom for fluoroform, and between the hydrogen atom and the carbon atom for bromoform.