Intermolecular forces overview

In this chapter, an overview of the respective intermolecular forces that may contribute to self-assembly processes is presented, with emphasis on those aspects that appear of relevance to a practising supramolecular chemist. 

An excellent historical overview of the subject of intermolecular forces is in Rowlinson, J. S. Cohesion, A Scientific History of Intermolecular Forces, 2002, Cambridge University Press, Cambridge. 

To end this overview, let me say a few words about the likely evolution of the calculations devoted to theoretically analyze the stability and reactivity of cyclodextrin complexes. Hybrid methods have recently opened the door for the most sophisticated ab initio and DFT methods to deal with molecular systems with hundreds or even thousands of atoms if the reactive center is well localized within a particular zone of the whole macromolecular system. As computers keep on growing in capacity and theoretical methods are progressively more well established, theoretical work on host guest complexes will be ready to make a jump from the qualitative predictions, already available now, to the quantitative results. This will provide a powerful tool for the experiments as theory will be helpful not just to explain reactions already known but to predict new reactions and effects of the supramolecular environment that have been until now out of reach of precise measurements (as intermolecular forces are quite tenuous, their theoretical evaluation is subject to noticeable relative errors). On the other hand, it is to be noted that electronic calculations alone are not able to disclose the rich molecular dynamics of such a large molecular systems. Up to now MC and MD procedures have been restricted to find the more stable conformations but they are able to tell us more details about the mechanism of the inclusion process and reactivity inside CD and other large guests. The applicability of these methods to such problems has also been... 

Quantum mechanical calculations on small molecule association suggest that there are five major contributions to the energy of intermolecular interactions in the gas phase (3, 4). The sum of these is the dissociation energy of the intramolecular complex represented in Fig. 4.1. Table 4.1 contains some examples of magnitudes of the different energy components for different interactions. This section provides a qualitative introduction to these forces. Section gives and overview of mathematical models suitable for computer calculations. 

IsraelachvUi JN (ed) (1985) Intermolecular and surface forces. Academic, London Tuzar Z (1996) Overview of polymer micelles. In Webber SE, Munk P, Tuzar Z (eds) NATO ASI series, series E Applied sciences, vol 327. Kluwer, Dordrecht... 

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