Dipole Moments of KF and KBr Measured by the Molecular-Beam Electric-Resonance Method

Abstract

The molecular-beam electric-resonance method has been used to obtain the dipole moments for different vibrational levels of 39K19F (v=0, 1, 2, 3, 4, 5), 41K19F (v=0), 39K79Br (v=0, 1, 2), and 39K81Br (v=0, 1, 2). The absolute errors in the determined dipole moments are systematical errors of one part in 104, while the relative errors are about five parts in 106 for the dipole moments of KF and 10 parts in 106 for the dipole moments of KBr.

Hyperfine spectra of KBr and KI

“…The molecules KBr and KI, along with several other alkali halides, were examined by both microwave and molecular beam methods relatively early in the history of these techniques [12][13][14][15][16][17][18]. Our current experiments improve upon these early measurements by 3 orders of magnitude in the precision of the hyperfine interactions for KBr and 5 orders of magnitude for KI.…”

Classical model for vibrationally excited alkali halides

“…The dipole moments /Ze at the equilibrium bond length are quoted in table 4 and compared with experimental data [2][3][4] ; agreement is mostly better than 5 per cent. The variation of the dipole moment with vibrational excitation is shown in figures 1 and 2.…”

“…Values of/zi and/zIi are given in table 5 and are compared with experimental data [2][3][4]. extrapolate smoothly to Be at zero excitation.…”

“…Unfortunately spectroscopic data [2][3][4] is only available for very low vibrational states (v 43). Molecular beam studies of these excited reaction products [5,6] require knowledge of the dipole moments and rotational constants for their interpretation [7].…”

Theory of the chemical bond. 2. Dipole moments of alkali halide molecules, bond polarity, and differential charge affinity

“…However, even for this rather select group of molecules no experimental measurements of µ 7 and µ,7 are available and only scattered measurements of µ,, exist. Thus, except in a few cases where available data allow a more accurate treatment, we utilize the approximation µ = A + BR (9) where A = hq> +p\(j)e/2a\Be (10) and B = -µµ^/3 , BeRe (11) Equation 9 is derived by substituting a from eq 4 into eq 3, setting 0 = 0 and rearranging.…”