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Discusses the use of the photoloc technique that permits the measurement of state-to-state differential cross section and the complete product polarization dependence for all moments of orientation and alignment. Location of the D-atom transfer as the cause of large differences in the Arrhenius pre-exponential factors of the Cl + C[sub 2]D[sub 6] reaction.

The chemical reaction of atomic chlorine with mixed monolayers of alkanethiolates having different chain lengths was investigated. In situ scanning tunneling microscopy was used to acquire time-lapsed series of images, allowing the measurement of the effect of monolayer structure and composition on reactivity. The rate of chemical reaction is strongly site-dependent. In particular, the boundary between two different-length alkanethiolates greatly promotes the reactivity of nearby molecules, much more so than any other native defect typical of single-component alkanethiolate monolayers. [ABSTRACT FROM AUTHOR]

We describe a thermal gas cracker designed to produce low fluxes of gas-phase radicals for use in radical-surface reaction studies. A resistively heated thin piece of highly oriented pyrolytic graphite is used as the pyrolysis filament, with the major advantage that this material remains inert at high temperatures. The instrument is built within an existing titanium sublimation pump, which simplifies construction and allows for self-pumping of the radical source. Thermal generation of Cl atoms from Cl2 was chosen to test the effectiveness of the instrument. 35Cl and 37Cl were generated with a concomitant decrease in parent 70Cl2 and 72Cl2 species, as monitored by a residual gas analyzer. The cracking fraction of Cl2 as a function of cell temperature is reported, with nearly full conversion achieved at high temperature. [ABSTRACT FROM AUTHOR]