Abstract
Cyclopropylchloromethyldifluorosilane, C-C3H5SiF2CH2Cl, Has Been Synthesized, and its Rotational Spectrum Has Been Recorded by Chirped-Pulse Fourier Transform Microwave Spectroscopy. the Spectral Analysis of Several Isotopologues Indicates the Presence of Two Distinct Conformations in the Free-Jet Expansion, Which Are Interconvertible through a Rotation of the Chloromethyl Group. a Partial Substitution Structure is Presented for the Lower Energy Conformation and is Compared to the Equilibrium Structure Obtained from Quantum Chemical Calculations. Additionally, the Presence of the Chlorine Nucleus Leads to the Rotational Transitions Splitting into Multiple Hyperfine Components and Χaa, a Measure of the Electric Field Gradient Along the a Axis, is Unusually Small at Merely +0.1393(73) MHz. Various Common Ab Initio and Density Functional Theory Methods Fail to Predict Good Quadrupole Coupling Constants (In the Principal Axis System) that Adequately Reproduce the Observed Hyperfine Splitting, Although Diagonalizing the Quadrupole Coupling Tensor from the Principal Axis System into a Nucleus-Centered Axis System Reveals that, overall, These Methods Calculate Reasonably the Electric Field Gradient About the Chlorine Nucleus. Finally, a Total of Nine Electric Dipole Forbidden, Quadrupole Allowed Transitions Are Observed in the Rotational Spectra of the Parent Species of the Higher Energy Conformation and the 37Cl Isotopologue of the Lower Energy Conformation. These Include Those of X-Type (No Change in Parity of Ka or Kc), Which, to Our Knowledge, is the First Time Such Transitions Have Been Observed in a Chlorine-Containing Molecule.
Recommended Citation
A. R. Davies et al., "Rotational Spectrum, Structure, and Quadrupole Coupling of Cyclopropylchloromethyldifluorosilane," Journal of Chemical Physics, vol. 160, no. 16, article no. 164309, American Institute of Physics, Apr 2024.
The definitive version is available at https://doi.org/10.1063/5.0203016
Department(s)
Chemistry
Publication Status
Available Access
International Standard Serial Number (ISSN)
1089-7690; 0021-9606
Document Type
Article - Journal
Document Version
Final Version
File Type
text
Language(s)
English
Rights
© 2024 American Institute of Physics, All rights reserved.
Publication Date
28 Apr 2024
PubMed ID
38661193
Comments
College of Charleston, Grant CHE-MRI-2019072