Photodissociation of the alkali iodides at 347.1 nm: Experimental angular distributions and dynamic model for their interpretation

The angular distributions of the alkali photofragment resulting from photodissociation of a molecular beam of NaI, KI, CsI, or RbI by a pulsed, linearly polarized laser beam at 347.1 nm have been measured. At the wavelength used, only production of ground state atoms is energetically feasible. The angular distributions indicate a trend in the perpendicular:parallel transition ratio from about 4:1 for NaI to about 2:1 for RbI and CsI. This interpretation assumes Hund’s case (c) coupling and excited states of pure perpendicular or parallel symmetry. A new model was developed to calculate the laboratory distribution from any center of mass distribution, including those resulting from multiphoton or saturated transitions. The individual counting model (ICM) simultaneously takes into account contributions from excited state lifetime, rotational distribution, and translational motion of the molecule. It is concluded that further study of the systems at several wavelengths in the lowest energy absorption band is...

[1]  L. W. Grossman,et al.  Saturated photodissociation of CsI , 1977 .

[2]  T. L. Rose,et al.  Importance of the perpendicular transition leading to ground state atoms in the photodissociation of NaI , 1977 .

[3]  K. Wilson,et al.  Molecular alignment and photofragment spectroscopy , 1975 .

[4]  D. Pritchard,et al.  Evidence for a molecular J–J coupling scheme for KI neutral potentials , 1975 .

[5]  T. L. Rose,et al.  Calculated laboratory angular distributions of photofragments for stationary flux detector , 1975 .

[6]  R. Bersohn,et al.  Theory of the angular distribution of molecular photofragments , 1974 .

[7]  T. L. Rose,et al.  Molecular‐beam photodissociation studies of alkali iodides , 1974 .

[8]  J. L. Kinsey,et al.  Potassium iodide chemiluminescence in diffusion flames and the KI upper‐state potential , 1974 .

[9]  J. L. Kinsey,et al.  Differential elastic scattering of potassium atoms by atomic iodine at thermal energies , 1974 .

[10]  J. Los,et al.  Rainbow, Stueckelberg oscillations and rotational coupling on the differential cross section of Na + I → Na+ + I− , 1973 .

[11]  M. Karplus,et al.  Perturbation theory and ionic models for alkali halide systems. I Diatomics , 1973 .

[12]  K. Wilson,et al.  Triatomic Photofragment Spectra: I. Energy Partitioning in NO2 Photodissociation, , 1972 .

[13]  R. Berry,et al.  Ultraviolet spectra of alkali halides in inert matrices , 1971 .

[14]  R. Berry,et al.  Curve Crossing in Collisional Dissociation of Alkali Halide Molecules , 1971 .

[15]  H. Wagner,et al.  Experimente zur elastischen Streuung von Kaliumatomen (2S1/2) an Jodatomen (2P3/2) in gekreuzten Molekularstrahlen , 1971 .

[16]  D. Horne,et al.  ELASTIC SCATTERING OF ALKALI ATOMS FROM IODINE ATOMS AND MOLECULES AT THERMAL ENERGIES. , 1970 .

[17]  G. Skewes,et al.  Discrete Structure in the Spectrum of Sodium Iodide Vapor , 1969 .

[18]  P. Davidovits,et al.  Ultraviolet Absorption Cross Sections for the Alkali Halide Vapors , 1967 .

[19]  W. Gordy.  Microwave spectroscopy in the region of 4-0.4 millimetres , 1965 .

[20]  J. W. Trischka,et al.  Large Differences in Surface Ionization Efficiencies between K and its Halides on the Contaminated Surface of a Pt Alloy (8% W) Wire , 1963 .

[21]  Leo Brewer,et al.  THE DISSOCIATION ENERGIES OF GASEOUS ALKALI HALIDES , 1961 .

[22]  R. Berry.  Interaction of Vibrational and Electronic Motion in Alkali Halide Molecules , 1957 .

[23]  P. Morse,et al.  Electronic and Ionic Impact Phenomena , 1970 .

[24]  G. Herzberg,et al.  Spectra of diatomic molecules , 1950 .

[25]  C. Zener.  Non-Adiabatic Crossing of Energy Levels , 1932 .