Trends in Bond Strengths

Extensive reviews of the effects of fluonnation on stmeture and bonding are available [75, 76, 77], and only the charactenstic trends in bond strengths will be covered here. The bond energies cited are average values corrected for the revised heats of formation of alkyl radicals [78], but their precision is seldom better than 2 kcal/mol for the fluoro compounds. 

As described in Section 6-, energy must be supplied to break any chemical bond. Bond energies, like bond lengths, vary in ways that can be traced to atomic properties. There are three consistent trends in bond strengths ... 

This trend in bond-strength continues with TTeF, but the more polarisable Te p- and d-orbitals allow for greater stabilisation of the cationic charge, giving the order TTF < TTeF < TSF in i/2(1). The difference between the first and second ionisation potentials, A 1/2, follows the trend TTeF < TSF < TTF. Again, the superior polarisability of Te over Se and S reduces intramolecular... 

Trends in Bonding Linear CN Versus CP Dimers The qualitative considerations above nicely match the trends in bond strength computed at the BP86/TZ2P level of DFT along both series 4a-4c and... 

Understanding the Trends in Bond Strengths and Bond Lengths... 

Know the trends in bond strengths and bond lengths for the common bonds. (Problem 2.37)... 

Stability as defined in this way is a good guide to reactivity, since the trend in bond strengths to other elements broadly follows the strengths to carbon. Thus the more stabilized the radical, the less reactive it will be towards a particular reagent. 

Trends in bond strengths show that almost every ion would follow the class a sequence in the gas phase, and the behavior in water is a partly a consequence of the weaker solvation of larger anions. With a class b ion such as Hg2+ the bond strengths decrease more slowly in the sequence Hg-F>Hg-... 

The trend in bond strengths for the T-metals is opposite to that which is found for the main group elements for example, the metal-ligand bond strength is ordered by 3d 4d < 5d. 

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