Bonding energy release associated with

The two main causes of the energy release associated with bonding are based on Coulomb s law of electric charge ... 

Considerable interest in the subject of C-H bond activation at transition-metal centers has developed in the past several years (2), stimulated by the observation that even saturated hydrocarbons can react with little or no activation energy under appropriate conditions. Interestingly, gas phase studies of the reactions of saturated hydrocarbons at transition-metal centers were reported as early as 1973 (3). More recently, ion cyclotron resonance and ion beam experiments have provided many examples of the activation of both C-H and C-C bonds of alkanes by transition-metal ions in the gas phase (4). These gas phase studies have provided a plethora of highly speculative reaction mechanisms. Conventional mechanistic probes, such as isotopic labeling, have served mainly to indicate the complexity of "simple" processes such as the dehydrogenation of alkanes (5). More sophisticated techniques, such as multiphoton infrared laser activation (6) and the determination of kinetic energy release distributions (7), have revealed important features of the potential energy surfaces associated with the reactions of small molecules at transition metal centers. 

The energy change associated with the process in which a solute dissolves in a solvent is called the heat of solution. This energy change is the net result of two processes 1) the energy required to break the solute-solute bonds, called the crystal lattice energy, and 2) the energy released when the solute particles bond with the solvent molecules, called the heat of hydration. 

This reaction involves breaking one H—H and one F—F bond and forming two H—F bonds. For bonds to be broken, energy mnst be added to the system—an endothermic process. Consequently, the energy terms associated with bond breaking have positive signs. The formation of a bond releases energy, an exothermic process, so the... 

Another manifestation of the relatively small release of energy associated with breaking the central bond comes from MP4/6-31G calculations on the reverse ring closure. ... 

However, the idea, that 96 may rearrange to the ortho isomer 93 via substituent migration or valence bond tautomerization, which would enable the CH3 loss to proceed as described in (20), could not be substantiated by experimental facts. For example, the secondary decompositions of the [M—CH3]+ ions formed from 93 and 96 are different with regard to the reaction channels and both the kinetic energy release and peak shapes associated with the reactions of interest. Moreover, the CA spectra of the [M—CH3]+ ions exhibit distinct differences. Thus, the [M—CH3]+ ions posses different ion structures and, consequently, a common intermediate and/or reaction mechanism for the process of methyl elimination from ionized 93 and 96 are very unlikely (22). 

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