Partial bond strength

The unusual carbon-halogen bond strength in vinyl halides compared to saturated alkyl halides has been ascribed to partial double-bond character (103, 104) coupled with increased a-bond strength (105) due to differences in... 

Fig. 5.8, Effect of diamino-silane solution concentration and modification on interfacial bond strength rh of GFRP (O) silane treated ( ) silane treated and partially removed. After Koenig and Emadipoiir...

At constant CO partial pressure, the rate determining step is a function of the HX bond strength. In the case of HSnR, the rate determining step is CO dissociation, Equation 9. For HSiR and H, it is the oxidative addition step. Equation 10. ... 

While fewer data are available, the utility of DFT in computing the bond strengths between transition metals and hydrides, methyl groups, and methylene groups has also been demonstrated (Table 8.2). Because of the non-dynamical correlation problem associated with the partially filled metal d orbitals, such binding energies are usually very poorly predicted by MO theory methods, until quite high levels are used to account for electron correlation. 

As described in Section IV.B, dibenzothiophenes, when substituted in positions adjacent to the sulfur atom, have reduced activity for direct sulfur extraction. As a result, catalysts that promote aromatic ring hydrogenation offer another route to desulfurization, as the partially hydrogenated ring presents much less steric restrictions to adsorption via r -S type bonding (17,21) or to oxidative addition to form a metallathiabenzene intermediate, as discussed in Section IV.E.3. In addition, the metal-S coordination bond strength is increased by increasing the electron density on sulfur, and the C-S bonds in hydrothiophenes are much weaker. 

The increase in stability resulting from resonance or electron delocalization is important in the discussion of a great variety of chemical questions. A partial list of topics should stress this point. Properties of dyes, ultraviolet absorption, bond strengths, thermal stabilities, free radical reactions, heats of reaction, and rates of chemical reactions in general may be influenced by resonance stabilization in the chemical species involved. 

The amount of adsorbed hydrogen decreases in the presence of halide ions [395, 396]. This is due to a decrease in the M-H adsorption energy induced by ion-specific adsorption with partial charge transfer. The decrease in M-H bond strength results in an increase of overpotential. The effect is lower for Cl and higher for I -. However two joint effects are operative one due to electronic modifications, and the other one of an electrostatic nature related to a change in the local electric potential... 

Physically, this means that the C=N bond is weakened because the lone pair is now partially transferred to the antibonding 7tCN orbital. The mixing coefficient A. - and the weakening - increase with the interaction. The reactivity order predicted on the basis of the CN bond strength is then 26 > 25 > 24 > 23, exactly opposite to the order obtained in Exercise 6 Explain this contradiction. 

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