An algorithm for the estimation of anharmonicity from a Morse potential
Abstract The wavefunctions of the ground and first excited state in a Morse potential are calculated and plotted, and the expectation values of the bond lengths
On the Existence of Conformers of Cyclobutyl Monohalides. III. Assignments of the Fundamentals of Bromocyclobutane and Chlorocyclobutane
The infrared spectra of the liquid and the vapor and the Raman spectra of the liquid of bromocyclobutane and chlorocyclobutane are reported. The 30 fundamentals of each halide are assigned and an approximate picture of the motions of those atoms, which are mainly involved in the fundamental modes, is given. There is one‐to‐one correlation between the fundamentals of bromocyclobutane with the fundamentals of chlorocyclobutane. This signifies that the amount of interaction between different modes is generally of the same order of magnitude in both halides, in contrast to the corresponding cyclopropyl halides. There is little symmetry correlation between the fundamentals of the cyclobutyl halides and cyclobutane; the out‐of‐plane ring‐bending (ring‐puckering) mode is an exception. In the Appendix, computer calculations of A‐ and C‐type band envelopes are presented and compared with observations; the computations include vibration—rotation interaction.
Infrared spectra of CHD2Cl and CHD2CCH and the geometries of methyl chloride and propyne
Abstract Five type B or type C bands in the gas phase infrared spectrum of CHD 2 Cl and two type C bands of CHD 2 CCH have been analyzed with a resolution of 0.2 cm −1 . All other fundamental vibrations have been located. Accurate determinations of ( A 0 - B 0 ) for each molecule are obtained from ground state combination differences, from which A 0 values are derived using microwave estimates of B 0 and C 0 . The combination of one A 0 rotational constant with B 0 and C 0 constants for all other isotopic species enables the ground state molecular geometry to be fixed within narrow limits, assuming that zero-point energy effects cause a shortening of the CH bond length by 0.002 A on deuteration. The CH bond lengths are in almost precise agreement with the values predicted from the position of the sole CH stretching vibration frequency for each molecule.