Potassium vibrationally excited, from

Determination of the total excitation cross section is again done by observing the resonance-line emission. Both the initial relative kinetic energy and the N2 temperature may be varied. First experiments of this type have studied the excitation of Na(3p) by N2, H2, and D2, vibrationally excited at 2000 to 3000°K for initial relative velocities from 1000 to 4000 m/sec l25-126 as well as both potassium and sodium.127 Recent studies with seeded beams 128131 on K + N2 and K + CO involved lower initial vibrational states v. This type of experiment is very difficult to analyze and evaluation invokes a number of assumptions for fitting the experimental data. A special threshold law for the energy dependence of the partial cross sections is adopted ... 

Emission spectroscopy has been used recently in an elegant attempt to elucidate the mechanism of the energy transfer process (10). Moulton and Herschbach have examined the emission from a triple molecul2ur beam experiment. Molecular beams of bromine and atomic potassium cross each other, and vibrationally excited KBr is formed, which is then collimated into a further beam. 

Both atomic and molecular emission and absoiption can be measured when a sample is atomized in a flame. A typical flame-emission spectrum was shown in Figure 24-19. Atomic emissions in this spectrum are made up of narrow lines, such as that for sodium at about 330 nm, potassium at approximately 404 nm, and calcium at 423 nm. Atomic spectra are thus called line spectra. Also present are emission bands that result from excitation of molecular species such as MgOH, MgO, CaOH, and OH. Here, vibrational transitions superimposed on electronic transitions produce... 

The surprisals calculated from all three of these models thus indicate a preference for vibrational energy in promoting the reaction. Work is now progressing on a temperature analysis of both the steady-state and laser-excited reactions in order to provide further evidence. The results to date are in agreement with the molecular beam study of the equivalent reaction of SFj with potassium."... 

---