Molecular beam comparison with electron

First attempts to investigate the photodissociation dynamics of Fe(CO)5 used molecular beam technology coupled with high intensity femptosecond lasers [47, 48]. It is important to note that these experiments relied on multiphoton absorption to populate the electronic excited states of Fe(CO)5. This work built on the results of earlier experiments using nanosecond pulsed lasers which provided information on the photoproduct distribution and their energies [37-40, 49-56]. The energies of the various dissociation processes for Fe(CO)5 are presented in Fig. 18 for comparison with the excitation photon energies and the absorption profile of Fe(CO)5. 

The molecular orbital description of He 2 predicts two electrons in a bonding orbital and two electrons in an antibonding orbital, with a bond order of zero—in other words, no bond. This is what is observed experimentally. The noble gas He has no significant tendency to form diatomic molecules and, like the other noble gases, exists in the form of free atoms. He2 has been detected only in very low pressure and low temperature molecular beams. It has a very low binding energy, approximately 0.01 J/mol for comparison, H2 has a bond energy of 436 kJ/mol. 

As an example, we show in Fig. 5 the projectile population, or probability for electron capture for protons colliding with molecular hydrogen at 1 keV for the orientation (a = 0, /3 = 90 molecular bond aligned with the incoming beam) (see Ref. [18]) that corresponds to the projectile trajectory aligned along the target molecular bond and perpendicular to it. Also, for comparison to the DIM model we present the results from Kimura [28] which have been multiplied by 0.1 to show them on the same scale. 

If the conditions of consistent ionization volume, a fixed electron beam, and consistent alignment of the cell orifice with the molecular beam-defining apertures are met, the integration over the electron beam and the molecular beam shape in Equation 48.29 will be constant from cell to cell. Provided that the cells are isothermal, the comparison between different molecular beams the ion ratio is given by ... 

ABSTRACT. This paper represents recent results on the reaction dynamics of the M + RX MX + R (M = alkali, X = halogen and R = radical group) family obtained from crossed molecular beam studies. The selectivity of the translational excitation of the reactants as weU as of the chemical nature of the M, R and X group is outlined. A comparison of these reactive processes with photofragmentation and electron attachment studies of the same RX molecule is also presented revealing important similarities. This common behaviour seems to indicate ttie same overall selectivity as a result of the similar main dynamics associated with the same R-X bond rupture. 

A comparison of mass spectra of dihexyl ether (molecular formula CH3(CH2)50(CH2)sCH3) obtained with low- (12 eV) and high- (70 eV) energy electron ionization beams. In these figures m/z indicates the mass to charge ratios of the measured ions, whereas the vertical axis represents their intensities relative to the base (most intensive) ion in that spectrum. From Lambert et al. (1998). 

---