The Molecular Beam Electric Resonance Method Study of Thallium Monochloride

R. O. Carlson; C. A. Lee; B. P. Fabricand

doi:10.1103/PhysRev.85.784

Access by Xinjiang University

The Molecular Beam Electric Resonance Method Study of Thallium Monochloride

R. O. Carlson^*, C. A. Lee, and B. P. Fabricand

Columbia University, New York, New York

^*A.E.C. Predoctoral Fellow.

PDF

Phys. Rev. 85, 784 – Published 1 March, 1952

DOI: https://doi.org/10.1103/PhysRev.85.784

Abstract

The hyperfine structure of the first rotational state of Tl ${Cl}^{35}$ and Tl ${Cl}^{37}$ was studied by the molecular beam electric resonance method. Two types of molecular transitions were observed: the conventional $m_{j}$ transition in very weak and in strong Stark fields, the type previously studied in several alkali fluorides; the $Δ J$ transition ( $J = 0 \to J = 1$ ), a molecular transition observed for the first time by molecular beam methods in this experiment.

Using the $m_{j}$ type transition, the electric quadrupole interactions involving the chlorine nuclei were determined for the $J = 1$ , $v = 0$ state. The values were $e q Q (Tl {Cl}^{35}) = - (15.795 \pm 0.004)$ Mc/sec, $e q Q (Tl {Cl}^{37}) = - (12.446 \pm 0.003)$ Mc/sec. The ratio of quadrupole interactions, 1.2691±0.0004, is in good agreement with the ratio found for other chlorine molecules and for the chlorine atoms. The quadrupole interaction increased in absolute value by ½ percent from one vibrational state to the next higher one. The spin-rotation (I.J) interaction constants in TlCl were +(73±2) kc for Tl, +(1.2±0.2) kc for ${Cl}^{35}$ , and +(1.0±0.2) kc for ${Cl}^{37}$ . These quadrupole interaction constants and the spin-rotation interaction constants for chlorine agree with the values given by the molecular beam magnetic resonance method.

From the rotational transition data and the strong Stark field $m_{j}$ transition data, the following molecular constants were evaluated for ${Tl}^{205}$ ${Cl}^{35}$ : the rotational constant $B_{e} = (2620.1 \pm 2.5)$ Mc/sec; moment of inertia $A_{e} = (320.2 \pm 0.4) \times 10^{- 40}$ g- ${cm}^{2}$ , internuclear distance $r_{e} = (2.541 \pm 0.002) A$ , and dipole moment for the zeroth vibrational state $μ_{0} = (4.444 \pm 0.014)$ Debye. The internuclear distance is in very good agreement with the electron diffraction value, (2.55±0.03)A, in contrast to the case of KCl and CsCl where discrepancies of 3 to 5 percent exist between electric resonance method values and the electron diffraction experiment values. Within the experimental error, the vibration-rotation interaction constant, (13±1) Mc/sec, agrees with the theoretical value predicted assuming a Morse potential for this molecule.

References (20)

H. K. Hughes, Phys. Rev. 72, 614 (1947)
J. W. Trischka, Phys. Rev. 74, 718 (1948)
V. Hughes and L. Grabner, Phys. Rev. 79, 314 (1950)
L. Grabner and V. Hughes, Phys. Rev. 79, 819 (1950)
Omitted endnote
V. Hughes and L. Grabner, Phys. Rev. 79, 829 (1950)
H. K. Hughes, Phys. Rev. 76, 1675 (1949)
G. Herzberg, Molecular Spectra and Molecular Structure, I. Diatomic Molecules (D. Van Nostrand Company, Inc., New York, 1950), second edition, p. 106 ff
Lee, Carlson, Fabricand, and Rabi, Bull. Am. Phys. Soc. 27, No. 1, 32 (1952)
V. Jaccarino and J. G. King, Phys. Rev. 83, 471 (1951)
C. H. Townes and B. P. Dailey, J. Chem. Phys. 17, 782 (1949)
R. Livingston, Phys. Rev. 82, 289 (1951)
H. Zeiger and D. Bolef, Phys. Rev. 85, 788 (1952)
H. M. Foley, Phys. Rev. 72, 504 (1947)
Omitted endnote
Berman, Kusch, and Mann, Phys. Rev. 77, 140 (1950)
W. Grether, Ann. Physik 26, 1 (1936)
R. G. Luce and J. W. Trischka, Phys. Rev. 83, 851 (1951)
Maxwell, Hendricks, and Mosley, Phys. Rev. 52, 968 (1937)
[8], p. 108

[c1] H. K. Hughes, Phys. Rev. 72, 614 (1947)

[c2] J. W. Trischka, Phys. Rev. 74, 718 (1948)

[c3] V. Hughes and L. Grabner, Phys. Rev. 79, 314 (1950)

[c4] L. Grabner and V. Hughes, Phys. Rev. 79, 819 (1950)

[c5] Omitted endnote

[c6] V. Hughes and L. Grabner, Phys. Rev. 79, 829 (1950)

[c7] H. K. Hughes, Phys. Rev. 76, 1675 (1949)

[c8] G. Herzberg, Molecular Spectra and Molecular Structure, I. Diatomic Molecules (D. Van Nostrand Company, Inc., New York, 1950), second edition, p. 106 ff

[c9] Lee, Carlson, Fabricand, and Rabi, Bull. Am. Phys. Soc. 27, No. 1, 32 (1952)

[c10] V. Jaccarino and J. G. King, Phys. Rev. 83, 471 (1951)

[c11] C. H. Townes and B. P. Dailey, J. Chem. Phys. 17, 782 (1949)

[c12] R. Livingston, Phys. Rev. 82, 289 (1951)

[c13] H. Zeiger and D. Bolef, Phys. Rev. 85, 788 (1952)

[c14] H. M. Foley, Phys. Rev. 72, 504 (1947)

[c15] Omitted endnote

[c16] Berman, Kusch, and Mann, Phys. Rev. 77, 140 (1950)

[c17] W. Grether, Ann. Physik 26, 1 (1936)

[c18] R. G. Luce and J. W. Trischka, Phys. Rev. 83, 851 (1951)

[c19] Maxwell, Hendricks, and Mosley, Phys. Rev. 52, 968 (1937)

[c20] [8], p. 108

Physical Review Journals Archive

Export citation

Export citation

The Molecular Beam Electric Resonance Method Study of Thallium Monochloride

Abstract

References (20)

Outline

Information

Filter

Filter

Article Lookup

Enter a citation