Guest molecules, stereospecific

The remarkable stereospecific correspondence between the complex template and the inorganic host is attributed to the hydrogen bonding between the host framework and the guest molecules. 

An examination of the behaviour in the solid state of guest molecules such as aliphatic ketones ( acetone and ethyl methyl ketone) and suromatic ketones (acetophenone and /7>Cl-acetophenone) in deoxycholic and apocholic acids has identified stereospecific addition of the guest molecules to the host by a hydrogen abstraction radical combination path. A flash photolytic study of fluorenone has shown that the triplet state reacts with electron rich alkenes in an electron transfer process. 

The simplicity of use, the relatively low cost and the broad range of possible guest molecules (small organic molecules, ions but also biological macromolecules) have since led to the important development of this technique, as illustrated by the increasing numbers of publications over recent years [17-25]. The fields of application of these imprinted polymer networks are very diverse. We can mention chromatographic supports (particularly for the separation of enantiomers) recognition elements in the preparation of specific sensors, catalysts, systems for stereospecific synthesis, and selective adsorbents. 

The inclusion compounds of 1 and 2 were obtained by crystallization from an appropriate solvent system containing a guest (vide infra). (R) -1 hen y I <21 y cy I - (A1) - pheny lg I y cine (1) molecules self-assemble to form a layer structure and (.V)-isopropyl phenyl sulfoxide molecules are stereospecifically included in the void between the layers (Figure 4)7 A sheet structure was also observed in THF-included crystals of (/ )-(l-naphthyl)glycyl-(/ )-phenylglycine (2), which were formed by crystallization of 2 from a mixed solvent of tetrahydrofuran (THF) and... 

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