Chemistry

Selective and reversible complexation of halogen-tagged aromatic VOCs by a quinoxaline cavitand-decorated Si surface is demonstrated. The specific host-guest interactions of the Si-bonded receptors are proved to be responsible of the surface recognition properties, while extracavity non specific adsorptions are totally suppressed compared to the bulk material.

The influence of structural parameters of the receptors on the response of cavitand coated quartz-crystal-microbalance (QCM) sensors to several organic vapors is reported. Enhanced selectivity toward specific analytes is obtained through CH-π interactions, while sensitivity can be improved by introducing long alkyl chains on cavitands to generate highly dispersed layers. Application of cavitand coated QCM sensors for the detection of organic analytes in water is also reported.

In the last few years there has been a huge demand to monitor different chemical species in the vapor phase, such as environmental pollutants, hazardous chemicals, food aromas, explosives, and volatiles in breath for disease diagnosis.1 Chemical vapor sensors are ...

... Stefano A. Levi Dr. 1 ,; Paolo Guatteri Dr. 2 ,; Frank CJM van Veggel Dr. ir. 1 ,; G. Julius Vancso Prof. ... 22 A. Friggeri , H. Schönherr , H.-J. van Manen , B.-H. Huisman , GJ Vancso , J. Huskens , FCJM van Veggel , DN Reinhoudt , Langmuir 2000, 16, 7757–7763. ...

A series of eight new cavitand receptors were prepared in an effort to obtain selective mass sensors for the detection of acetates. The desired synergy between the cavity inclusion and H-bonding was obtained introducing a carboxylic residue on one of the bridging groups, which delimitate the cavity at the upper rim. The orientation of the COOH group inward or outward (cavitands 3-in and 4-out) determines a different ability to detect acetates according to their chain length. Acetate versus ester discrimination has been obtained by extending the cavity rim using a 4-chloro-phenoxy substituent in the inward position (cavitand 8-out).