Photoexcitation of reaction complexes in the reaction K+NaCl→KCl+Na

Abstract

Emission at the Na D lines has been observed from the intersection of crossed molecular beams of K and NaCI irradiated by a cw dye laser at wavelengths from 590 and 735 nm. The three-beam signal exhibits a threshold near 735 om and is linearly dependent on the laser and molecular beam intensities. This three-beam signal has been observed under experimental conditions in which all two-beam signals are accounted for, and is attributed to the formation ofNa* by photoexcitation of the KNaCI reaction complex. The effective two-body cross section for the process is approximately 10-21 cm 2 in a laser field of 1.5 kW /cm 2 •

Role of Fine Structure States in a Chemical Reaction: Na* + KBr → NaBr + K*

“…The K* fluorescence signal is extracted from the PMT signal by appropriate sums of the various beam on/off signals, as described in ref . Since the absolute signal depends on the intensities of each of the beams, these signals are normalized for convenience to 100 for the K D2 emission which results from excitation of the Na D2 transition.…”

“…The only significant background was leakage of sodium D line emission through the interference filters which attenuate visible light outside the bandpass by a factor of 10 6 . This background was easily separated from the signal of interest by chopping each of the three beams …”

“…This background was easily separated from the signal of interest by chopping each of the three beams. 4 The two potassium interference filters are centered at 7664 and 7697 Å for the D2 (7665 Å) and D1 line (7699 Å), respectively, for filter temperatures of 29 °C. The bandpass of both filters is 3 Å fwhm and is dependent on temperature, with a shift of ∼0.1 Å per degree Celsius toward the red.…”

Threshold Behavior in Electron-Transfer Collisions between Rubidium Atoms and C2F5Cl or C2F5I Molecules

“…The seeded atomic beam crosses a molecular beam at an angle of 120° in an apparatus sketched in Figure , slightly modified from one described earlier. − The molecular beam is nominally a 10% mixture of a test gas in argon or helium expanded through a 0.002-in. diameter ruby nozzle at room temperature.…”

Ultrafast Reaction Dynamics

“…However, this wing emission can, with the help of theory, project into the frequency domain features of the dynamics. Similarly, instead of transitionstate emission, transition-state absorption 11 can be achieved by tuning the laser away from reactant and product absorption frequencies, but the signal is very weak.…”