The parameters of stability, guest binding reversibility, and Gibbs energy of guest inclusion were determined for clathrates of adamantylcalix[4]arene (1). These data provide a new insight into the structure-property relationships in vapor sensor applications of clathrate-forming hosts. A thin layer of 1, used in the quartz microbalance (QCM) sensor, demonstrates a selectivity for organic vapors, which depends on the regeneration technique after the guest binding. Complete regeneration of 1 on the sensor surface was reached through the exchange of bound guest with ethanol vapor, which forms an unstable clathrate with 1. The efficiency of the used regeneration technique was proved by comparing the QCM data with the isotherms of guest vapor sorption by guest-free host 1 and with the data of simultaneous thermogravimetry and differential scanning calorimetry for the saturated clathrates of 1. In sensor, the extent of host regeneration without guest exchange depends on the guest molecular structure. This extent, or guest-binding reversibility parameter, being determined in a combination with the sensor responses of completely regenerated 1 to guest vapors, increases the recognition capability of single sensor device. Using this technique, 13 of 15 studied guests were discriminated. The structural hints on the suitable sensor properties of 1 were found in the determined X-ray monocrystal data for clathrate of this host with toluene.

An effective preparation procedure is offered for β-cyclodextrin (bCD) clathrates with volatile guests of moderate hydrophilicity, which otherwise require a finely tuned optimization of the bCD/water/guest ratio. The proposed procedure includes guest exchange in a water-free bCD matrix. As a result, more stable clathrates with a higher inclusion capacity can be prepared than by direct saturation of dried or hydrated bCD. To find an optimal preparation method, the structure-property relationships were studied for four different ways of bCD clathrate formation with guests of varying molecular structure. The study was much simplified by used procedures excluding direct contact of guest and water liquids with bCD. Besides, in clathrate preparation experiments, the thermodynamic activities of water and guest were varied independently, which makes explicit the role of water in this process. Hydration of bCD reduces its inclusion threshold for hydrophobic guests by their activity (relative vapor pressure), giving favorable hydration effect for their inclusion. Besides, water competes with hydrophilic guests for binding sites in bCD at high water activities. Together with bCD dehydration by excess of hydrophilic guests, these observations give a complete thermodynamic picture, which may be fruitful for elaboration of guest encapsulation techniques by cyclodextrins.

The interest in functional supramolecular systems for the design of innovative materials and technologies, able to fundamentally change the world, is growing at a high pace. The huge array of publications that appeared in recent years in the global literature calls for systematization of the structural trends inherent in the formation of these systems revealed at different molecular platforms and practically useful properties they exhibit. The attention is concentrated on the topics related to functional supramolecular systems that are actively explored in institutes and universities of Russia in the last 10–15 years, such as the chemistry of host–guest complexes, crystal engineering, self-assembly and self-organization in solutions and at interfaces, biomimetics and molecular machines and devices. The bibliography includes 1714 references.

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