All Items 2 Collection 1 The Octagon 2 Contributor 5 Leung, Helen O. (Department of Chemistry, Amherst College) 2 Amberger, Brent (Department of Chemistry, Amherst College) 1 Marshall, Mark D (Department of Chemistry, Amherst College) 1 Marshall, Mark D. (Department of Chemistry, Amherst College) 1 Mueller, Jessica L. (Department of Chemistry, Amherst College) 1 Topic 8 Electrostatics 2 Molecular structure 2 Argon 1 Complex compounds 1 Fourier transform infrared spectroscopy 1 Microwave spectroscopy 1 Quasimolecules 1 Tunneling (Physics) 1 show more 3 show fewer Part Of 1 The Amherst College Octagon 2 Genre 1 Articles 2 Subject 8 Electrostatics 2 Molecular structure 2 Argon 1 Complex compounds 1 Fourier transform infrared spectroscopy 1 Microwave spectroscopy 1 Quasimolecules 1 Tunneling (Physics) 1 show more 3 show fewer Exploring the sterically disfavored binding of acetylene to a geminal olefinic hydrogen-fluorine atom pair: The microwave spectrum and molecular structure of cis-1,2-difluoroethylene–acetylene Leung, Helen O. (Department of Chemistry, Amherst College) The microwave rotational spectrum of the gas-phase bimolecular heterodimer formed between cis-1,2-difluoroethylene and acetylene is obtained using Fourier transform microwave spectroscopy from 5.9 to 21.2 GHz. Rotational constants derived from the analysis of the spectra for the normal isotopologue and singly substituted ¹³C isotopologues, obtained in natural abundance, allow the determination of the structure of the complex, which, in the absence of a fluorine-hydrogen atom pair located cis to each other, adopts a sterically disfavored geometry (“side-binding”) in which the acetylene interacts with a geminal fluorine-hydrogen atom pair. Structural details are found to be similar to those of previously studied heterodimers with side-binding of acetylene to fluorine while reflecting the degree of halosubstitution. A detailed comparison with the (Z)-1-chloro-2-fluoroethylene-acetylene complex reveals information regarding the relaxed steric requirements for hydrogen bonding to chlorine as opposed to hydrogen bonding to fluorine. Exploring the sterically disfavored binding of acetylene to a geminal olefinic hydrogen-fluorine atom pair: The microwave spectrum and molecular structure of cis-1,2-difluoroethylene–acetylene The molecular structure of and interconversion tunneling in the argon-cis-1,2-difluoroethylene complex Marshall, Mark D. (Department of Chemistry, Amherst College) Guided by ab initio predictions, the structure of the gas-phase complex formed between cis-1,2-difluoroethylene and an argon atom in a pulsed molecular jet is determined using microwave spectroscopy in the 5.7–21.5 GHz region of the spectrum. This is a non-planar, symmetric species, with the argon atom located in the FCCF cavity of the difluoroethylene. The transitions in the microwave spectrum are observed to be split by an interconversion tunneling motion between the two equivalent configurations for the complex with the argon atom located either above or below the difluoroethylene molecular plane. Both one- and two-dimensional discrete variable representation calculations of the tunneling splitting using the ab initio interaction potential for the complex suggest that the barrier to interconversion is overestimated by theory. The molecular structure of and interconversion tunneling in the argon-cis-1,2-difluoroethylene complex
