Publication
Title
Vibrational-spectrum, conformational stability, barriers to internal rotation, structural parameters and ab initio calculations of bromomethyl methyl ether
Author
Abstract
The Raman and far-infrared spectra at a resolution of 0.10 cm-1 of gaseous bromomethyl methyl ether, BrCH2OCH3, and three of its deuterium isotopes, d2, d3 and d5, were recorded in the 350-50 cm-1 region. The fundamental asymmetric torsional and methyl torsional modes for the d0 molecule are extensively mixed and were observed at 176 and 130 cm-1, respectively, for the stable gauche conformer with each mode having excited states falling to lower frequency. An estimate is given for the potential function governing the asymmetric rotation. On the basis of a one-dimensional model the barrier to internal rotation of the methyl moiety is determined to be 549 +/- 8 cm-1 (1.57 +/- 0.02 kcal mol-1). A complete assignment of the vibrational fundamentals for all four isotopic species observed from the infrared (3500-50 cm-1) spectra of the gas and solid and Raman (3200-10 cm-1) spectra of the gas, liquid and solid is proposed. All of these data are compared with the corresponding quantities obtained from ab initio Hartree-Fock gradient calculations employing the STO-3G* basis set. Additionally, complete r0 geometries were determined from the combined previously reported microwave data and C-H distances determined from infrared studies along with carbon-hydrogen angles transferred from the corresponding chloride. The heavy atom structural parameters (distance in angstrom, angles in degrees) are r(Cl-Br) = 1.996 +/- 0.005; r(C1-O) = 1.359 +/- 0.005; r(C2-O) = 1.433 +/- 0.005; BrCO = 113.7 +/- 0.3; less than with left parenthesis through C1OC2 = 113.5 +/- 0.3 and dih BrC1OC2 = 70.9 +/- 0.3. All of these results are discussed and compared with the corresponding quantities obtained for some similar molecules.
Language
English
Source (journal)
Journal of Raman spectroscopy. - Dordrecht
Publication
Dordrecht : 1992
ISSN
0377-0486
DOI
10.1002/JRS.1250230405
Volume/pages
23 :4 (1992) , p. 205-223
ISI
A1992HT11500005
Full text (Publisher's DOI)
UAntwerpen
Faculty/Department
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identifier
Creation 03.01.2013
Last edited 15.11.2024
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