MOLECULAR MODELING OF HOST-GUEST INTERACTIONS FOR MASS SENSITIVE CHEMICAL SENSORS

Paracyclophanes are effective coatings for mass sensitive chemical sensors. The enzyme analogue recognition can preferably be used to detect aromatic and halogenated hydrocarbons. Molecular modelling by the MM3 force field allows the prediction of an efficient analyte inclusion. Besides the necessary steric complementarity it could be shown that the interaction between the methyl groups of aromatic guests (e.g. toluene) and the aromatic walls of the host is essential for host-guest complexation. These phenomena get more pronounced if bicyclic cyclophanes are applied and these sensitive materials enable the detection of only a few ppm of toluene with SAW devices. Furtheron. the electron-rich diphenylether moieties of these hosts guarantee interactions with electron-deficiency analytes such as chlorinated hydrocarbons with a selectivity superior to that of the monocyclic materials.