Solid-state host—guest chemistry

Solid-state host-guest chemistry (also known as inclusion or clathrate chemistry). 

Solid-state host-guest chemistry dates to the discovery of chlorine clathrate hydrate by Davey in 1810 and represents cocrystallization of two or more chemically... 

As it is currently practiced, supramolecular chemistry, with its emphasis on the interactions between molecules, underpins a very wide variety of chemistry and materials science impinging on molecular host-guest chemistry, solid-state host-guest chemistry, crystal engineering and the understanding and control of the molecular solid state (including crystal structure calculation), supramolecular... 

This entry to supramolecular chemistry allows one, at the same time, to develop a host-guest chemistry because the space inside the cucurbituril barrel is sufficient to confine small "guesf molecules. This is illustrated with the crystallization of the supramolecular adduct [W3S4(H20)8Cl](pyH ccuc) Cl4a 5.5 H2O with a pyridinium cation inside the cucurbituril cavity [48]. The introduction of guest molecules may vary the net charge on the assembly and consequently the whole packing in the solid state. 

The exploitation of the reactivity of molecular crystals lies close to the origins of crystal engineering and is at the heart of the pioneering work of Schmidt [47a]. The idea is that of organizing molecules in the solid state using the principles of molecular recognition and self-assembly. Successful results have been obtained with bimolecular reactions, particularly [2+2] photoreactivity and cyclisation [47b,c]. Another important area is that of host-guest chemistry. 

We saw in Figure 1.2c that supramolecular chemistry is not just about solid state or solution host-guest chemistry but increasingly emphasises self-assembly and the construction of multi-nanometre scale devices and ultimately materials based on nanometre-scale components (a nanometre is 10 9 of a metre). Strict supramolecular self-assembly (Chapter 10) involves the spontaneous formation of a multi-component aggregate under thermodynamically controlled conditions based on information encoded within the individual building blocks (referred to as tectons ) themselves. The aggregate might comprise only one kind of molecule (as in the multiple copies of the same protein that comprise... 

The above examples show that proton transfer resulting in keto-enol tau-tomerism cannot be studied separately from the environment. The equilibrium between keto and enol forms, both in solution and in the solid state is a derivative of numerous noncovalent interactions that can stabilize a particular isomer. In this context, host-guest chemistry can shed more light towards understanding of the proton-transfer mechanism in biological systems. 

For conceptually similar approaches, see (a) Ito, Y. Borecka, B. Trotter, J. Scheffer, J. R. Control of Solid-State Photodimerization of fraws-Cinnamic Acid by Double Salt Formation with Diamines. Tetrahedron Lett. 1995, 36, 6083-6086 (b) Amirsakis, D. G. Garcia-Garibay, M. A. Rowan, S. J. Stoddart, J. F. White, A. J. P. Williams, D. J. Host-Guest Chemistry Aids and Abets a Stereospecific Photodimerization in the... 

Toda, F. (1989) Studies of Host-Guest Chemistry. -Fundamentals and Applications of Molecular Recognition and their Development to New Organic Solid State Chemistry-, J. Syn. Org. Chem., Jpn. 47, 1118-1131. 

Keywords CP/MAS Host-guest chemistry Molecular motion Calixarenes Cyclodextrins Cyclophosphazenes Fullerenes Solid-state NMR... 

When greater selectivity is required in the solid-state reaction, host-guest chemistry techniques can be applied efficaciously. Reaction in the solid state of the guest compound as its inclusion complex crystal with a chiral host can give an optically active reaction product. Various host compounds have been designed by us to follow this simple principle. 

Lichen, Y. Selective anion binding and solid-state host- 40. guest chemistry of an extended cavity calix[6]pyn ole. 

Armisakis. D.G. Garcia-Garibay. M.A. Rowan. S.J. Stoddart. J.F. White. A.J.P. Williams. D.J. Host-guest chemistry aids and abets a stereospecific photodimerization in the solid state. Angew. Chem., Int. Ed. 2001, 40. 

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