Host-guest interactions, crystallographic studie

One of the aims of the crystallographic studies is to visualize the spatial conditions of non-H-bond type of interactions. Van der Waals forces (dispersion and exchange repulsion) and polarization are representatives of such interactive forces. They are governed by geometric features such as contact surfaces and volumes of the host and guest matrices. 

Other calix[4]arenes combine both a host and a guest unit, such as the pyridinium-conjugated derivative 11-17 (Scheme 12.12) which forms oligomers by cation- r interaction both in solution, in the solid state, and also in the gas phase, as revealed by H NMR spectroscopy, crystal structure determination, and crystallographic studies. °... 

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