Through-space bond components

Through-Space and Through-Bridge Bond Components. 81... 

The second component is called afield effect and is attributed to through-space interactions of the electric dipoles resulting from polar bonds. 

R.F. Nalewajski, Through-space and through-bridge components of chemical bonds, J. Math. Chem. in press. 49 (2011) 371. 

Another way to look at this resuft comes from recognizing the special entropy problem involved in cycloaddition reactions. A very precise orientation of the two molecules is required for two bonds to be formed at once. These reactions have large negative entropies of activation (Chapter 41)—order must be created at the transition state as the two components align with one another. The through-space attractive HOMO/LUMO interaction between the two molecules can lead to an initial association that can be compared to a squishy sandwich with... 

An important question in biological electron transfer is related to through-space and through-bond processes.74 Whereas through-bond processes were studied with [2]-rotaxanes 102 and 107, [2]-rotaxane 111 of Figure 2.38 was synthesized with the purpose of addressing the through-space question in a novel approach.75,76 In such a rotaxane the donor (Zn porphyrin stoppers) and the acceptor (Au porphyrin appended to the macrocycle) components are maintained in the same molecule by mechanical bonds only. It is therefore... 

The inductive component in Equation (5) (p a ) is the sum of the through-space (field effect, F) and through-bond inductive effect (I). The significance of the field effect (f) is discussed later. 

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