Energetic states diversity

A qualitatively different approach to probing multiple pathways is to interrogate the reaction intermediates directly, while they are following different pathways on the PES, using femtosecond time-resolved pump-probe spectroscopy [19]. In this case, the pump laser initiates the reaction, while the probe laser measures absorption, excites fluorescence, induces ionization, or creates some other observable that selectively probes each reaction pathway. For example, the ion states produced upon photoionization of a neutral species depend on the Franck-Condon overlap between the nuclear configuration of the neutral and the various ion states available. Photoelectron spectroscopy is a sensitive probe of the structural differences between neutrals and cations. If the structure and energetics of the ion states are well determined and sufficiently diverse in... 

The biochemical applications involve the electronic nature of the components of DNA and proteins, especially the charge distributions, electron affinities, and gas phase acidities of purines and pyrimidines and amino acids. The role of electron reactions in diverse areas such as cancer, electron conduction, and sequence recognition all depend on fundamental energetic properties such as electron affinities and solution energies. We explain nonadiabatic experimental data from radiation chemistry by excited anionic states of biological molecules [24],... 

The diversity around us, including the biological world (life), emerges from and depends on the ability to distinguish and exploit alternatives (selectivity). This discriminative process can rest on the energetic differences in thermodynamically definable and thus time-invariant states representing, however, in many cases, a... 

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