Communication: Hydrophobic coatings for mass-sensitive sensor devices, which yield a negligible water cross sensitivity, are the aim of the reported research. Molecular modeling was used to gain an understanding of the binding mechanism of some solvent molecules with a tetraazaparacyclophane containing alkyl substituents at the amino bridge-heads (CPO44VAL)-the figure shows the calculated geometry of the benzene complex of CPO44VAL. The theoretical results were then compared with the actual performance of CPO44VAL in devices.