Synthesis of novel β-cyclodextrin and calixarene derivatives and their use in gas sensing on the basis of molecular recognition

In order to examine the molecular recognition effect of a three-dimensional hydrophobic cavity, seven beta-cyclodextrin derivatives (1-7) bearing hydrophobic substituents on the primary side, and three structurally related calixarene derivatives (8-10) were synthesized and used as coating materials for a piezoelectric chemical sensor to detect some aliphatic amines in the gaseous state. The results obtained indicate that these synthetic receptors show considerable sensitivity and selectivity toward the analytes. It is interesting that the cyclodextrins and calixarenes show distinctly different sensitivity profiles for monoamino analytes, which were interpreted from the viewpoint of host-guest chemistry, that is, the response mechanism is mainly based on the molecular recognition behavior of the host compounds. It is also revealed that hydrogen bonding can be the major driving force in the coating-analyte interaction, and that there exists interstitial binding for the ethylenediamine-cyclodextrin interaction, The present study demonstrates that beta-cyclodextrin and calixarene derivatives would serve as sensitive coating materials for piezoelectric chemical sensors.