High-Resolution Infrared Diode Laser Spectroscopy of CBr

Rotational Spectrum of CBr by Kinetic Microwave Spectroscopy of 193-nm Photolysis Products of Bromoform

“…The major error on this constant remains the contribution from q which we determine very close to the upper limit established by Marr et al Our value of D also agrees, within experimental error, with that from the infrared work, but it should be pointed out that there is a typographical error (12) in their publication (7) and that the value for D e should read 0.883(37) ϫ 10 Ϫ6 cm Ϫ1 . In our first fits we allowed the sextic centrifugal distortion constant H to vary.…”

“…Best-fit parameters are shown in Table 2. The spectra give no useful information about the value of the spin-orbit constant A, which was hence fixed to the value of 466.00 cm Ϫ1 , calculated from the values of A e , ␣ A , and ␤ A given by Marr et al (7) (and in agreement with the value of 466 Ϯ 10 cm Ϫ1 estimated by Dixon and Kroto (5)). As pointed out by Brown et al (11), the spin-rotation constant ␥, and A J , the centrifugal correction to the spin-orbit constant, cannot be determined independently.…”

Primary and Secondary Processes in the Photodissociation of CHBr3

“…Calculated energies are shown schematically inFigure 8. The very small exit barrier from the three-center elimination of HBr is consistent with previous reports of three-center hydrogen halide elimination.Riehl and Morokuma have examined the three-center elimination ofHCl from vinyl chloride?9 The calculated transition state is qualitatively similar to the HBr transition state of the present study with an elongated carbon-halogen bond length and a modestly lengthened C-H bond…”

“…5 Ofthe bromomethane derivatives, bromoform has been found to be the greatest contributor of bromine to the Arctic atmosphere 6 with an atmospheric lifetime of approximately two weeks. 9 The authors were also able to obtain the CHBr radical from CHBr 3 at this wavelength and determined that the products also resulted from a single photon process, suggesting an additional fate of the energized CHBr 2 radicals. 1…”

Vibronic Reassignment of theÃ1A′′ ←X̃1A′ Band System of Bromomethylene

“…It was observed previously in studies of CBr and CCl (8,9) that vibrational relaxation from ground state excited vibrational levels is evidenced as a faster decay time in the recorded waveforms of hot band transitions. Thus absorption waveforms of transitions from different band systems were also recorded to obtain further evidence for the postulated hot band assignments described here.…”