Tipping the balance between electrostatics and steric effects: The microwave spectra and molecular structures of 2-chloro-1,1-difluoroethylene-acetylene and cis-1,2-difluoroethylene-acetylene
Leung, Helen O.
Loading…
Permalink
https://hdl.handle.net/2142/100509
Description
Title
Tipping the balance between electrostatics and steric effects: The microwave spectra and molecular structures of 2-chloro-1,1-difluoroethylene-acetylene and cis-1,2-difluoroethylene-acetylene
Author(s)
Leung, Helen O.
Contributor(s)
Marshall, Mark D.
Issue Date
2018-06-19
Keyword(s)
Rotational structure/frequencies
Abstract
We have found that the observed average structures of haloethylene-protic acid heterodimers result from an interplay between favorable electrostatic interactions and steric effects. For vinyl fluoride and 1,1-difluoroethylene complexes, steric effects predominate and the acid binds across the double bond (“top”), while for trifluoroethylene, favorable electrostatics forces the complexes to adopt a sterically strained structure with the acid at one end of the olefin (“side”). A relaxation of steric requirements for binding with a chlorine atom leads to different geometries being observed for each of the vinyl chloride complexes with hydrogen fluoride, hydrogen chloride, and acetylene. The side binding motif to chlorine persists in (Z)-1-chloro-2-fluoroethylene–acetylene despite the presence of the more electronegative fluorine atom. For 2-chloro1,1-difluoroethylene ethylene–acetylene, the acetylene is presented with the option of top binding to fluorine versus side binding to chlorine, whereas with cis-1,2-difluoroethylene, the only option is side binding to fluorine. The structures of these two complexes are compared to reveal the balance between electrostatics and sterics.
Use this login method if you
don't
have an
@illinois.edu
email address.
(Oops, I do have one)
IDEALS migrated to a new platform on June 23, 2022. If you created
your account prior to this date, you will have to reset your password
using the forgot-password link below.
