Microwave spectrum of dibromomethane. Part 2.—Nuclear quadrupole coupling tensor
- 1 January 1971
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in Transactions of the Faraday Society
- Vol. 67, 1551-1568
- https://doi.org/10.1039/tf9716701551
Abstract
The nuclear quadrupole hyperfine structure in the spectra of four isotopic species of dibromomethane, CH2 79Br2,CH2 81Br2,CD2 79Br2 and CD2 81Br2, has been analyzed to give the quadrupole coupling tensor directly, using second-order perturbation theory. Coupling constants (MHz) in the principal inertial axes system are as follows, CH2 79Br2: χaa= 334.9 ± 12, χbb=–25.2 ∓ 6, χcc=–309.7 ∓ 6, χab= 395.9 ± 13; CH2 81Br2: χaa= 280.6 ± 6, χbb=–21.4 ∓3, χcc=–259.2 ∓ 3, χab= 332.5 ± 10. Consistent values are reported for CD2 79Br2 and CD2 81Br2. Diagonalization of the quadrupole coupling tensor yields, CH2 79Br2: χzz= 591 ± 20, χxx=–281∓14, χyy=–310 ∓ 6 and CH2 81Br2: χzz= 495 ± 12, χxx=–236∓9, χyy=–259.2∓3. It is concluded that the Br-bond projection coincides with the internuclear axis within the experimental error of 1°; if bent bonding is involved in the C—Br bond the bend cannot be more than the experimental error of 2°. The analysis of the nuclear quadrupole hyperfine structure of a dibromine molecule is outlined and a comprehensive list of assignments presented in an appendix.Keywords
This publication has 0 references indexed in Scilit: