Laser spectroscopy of the C1Σ+–X1Σ+ transition of ScBr

Xia, Y.; Liao, Zhenwu; Yang, Mei; Chan, Man‐Chor; Cheung, Any

doi:10.1016/j.cplett.2012.01.017

Cited by 5 publications

(2 citation statements)

References 29 publications

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“…We consider the chemiluminescent emission characterizing 16 reactions of the group 3 metals Sc, Y, and La and their dimers with F 2 , ClF, and Cl 2 as well as SF 6 ; Sc with Br 2 and ICl; Y with Br 2 and IBr; and Sc 2 and Y 2 with Cl and Br atoms. The available spectroscopic data from experiments ,,,,− ,− and calculations ,,− ,− ,− ,− are given in Tables – .…”

Section: Resultsmentioning

confidence: 99%

Observation of Selectively Populated Monohalide Excited States from the Reactions of Group 3 Metal (Sc, Y, and La) Monomers and Dimers with Halogen-Containing Molecules

et al. 2022

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The chemiluminescent reactions of the group 3 metals Sc and Y with F 2 , Cl 2 , Br 2 , ClF, ICl (Sc), IBr (Y), and SF 6 and La with F 2 , SF 6 , Cl 2 , and ClF have been studied at low pressures (6 × 10 −6 to 4 × 10 −4 Torr) using a beam-gas arrangement and extended to the 10 −3 Torr multiple collision pressure range. Contrary to previous reports, the observed chemiluminescent spectra are primarily attributed to emission from the metal monohalides. Extensive pressure and temperature dependence studies and high-level correlated molecular orbital theory calculations of the bond dissociation energies support this conclusion and the attribution of the chemiluminescence. Evidence for the "selective" production of a monohalide excited electronic state is obtained for several of the Sc and Y reactions. All reactions producing the metal monofluorides are first order with respect to the oxidant, while reactions producing the monochlorides and monobromides are found to be "faster than first order" with respect to the oxidant. This difference is associated with the metal halide bond dissociation energies and the metal halide product internal density of states. Analysis of the temperature dependence for six representative reactions indicates that the "selective" excited-state formation of the metal monohalides proceeds via a direct mechanism with negligible activation energy. We compare and contrast the present results with previous experiments and interpretations which have assigned the selective emission from these systems to the group 3 dihalides produced in a two-step reaction sequence analogous to an electron jump process. The current results suggest a distinctly different interpretation of the observed processes in these systems. The observed selectivity observed in these studies is remarkable given the significant number of known and potential excited states in the scandium and yttrium halides as well as their different electronic configurations.

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Section: Resultsmentioning

confidence: 99%

Observation of Selectively Populated Monohalide Excited States from the Reactions of Group 3 Metal (Sc, Y, and La) Monomers and Dimers with Halogen-Containing Molecules

et al. 2022

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“…Equilibrium parameters were also established for the four most abundant isotopologues. This work significantly extends the characterization of 3d-bromide species, which has been limited to microwave/millimeter-wave measurements of ScBr, 26 CuBr, 27,28 and NiBr, 29 and rotationally resolved optical work for ScBr, 30 TiBr, 31 and NiBr. 32 It also allows direct comparison of chemical trends within the halide group, complementing our previous studies of ZnCl and ZnF.…”

Section: Introductionmentioning

confidence: 92%

The pure rotational spectrum of the ZnBr radical (X2Σ+): Trends in the zinc halide series

Burton

Ziurys

2019

The Journal of Chemical Physics

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The pure rotational spectrum of ZnBr (X 2 Σ + ) has been recorded in the frequency range 259-310 GHz using millimeter-wave direct absorption techniques. This study is the first quantitative spectroscopic investigation of this free radical. ZnBr was synthesized in a DC discharge by the reaction of zinc vapor in argon with one of three reagents: BrCH 3 , Br 2 CH 2 , or Br 2 . Eight rotational transitions were measured for six isotopologues ( 64 Zn 79 Br, 64 Zn 81 Br, 66 Zn 79 Br, 66 Zn 81 Br, 68 Zn 79 Br, and 68 Zn 81 Br), all of which exhibited spin-rotation interactions. Furthermore, transitions originating in the v = 1 through 3 excited vibrational states were obtained for certain isotopologues. Five rotational transitions were also recorded for 67 Zn 79 Br, in which hyperfine splittings were observed arising from the 67 Zn nucleus (I = 5/2). The spectra were analyzed using a Hund's case (b βJ ) Hamiltonian, and rotational, spin-rotation, and 67 Zn magnetic hyperfine constants were determined. Equilibrium parameters were also derived for the 64 Zn 79 Br, 64 Zn 81 Br, 66 Zn 79 Br, and 66 Zn 81 Br isotopologues, including the vibrational constant, ω e = 286 cm −1 . The equilibrium bond length was derived to be r e = 2.268 48(90) Å. Analysis of the 67 Zn hyperfine parameters suggest a decrease in ionic character in ZnBr from the other known zinc halides, ZnF and ZnCl.

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