CAVITANDS AS SELECTIVE MATERIALS FOR QMB SENSORS FOR NITROBENZENE AND OTHER AROMATIC VAPORS

The sensitivity of vase-like cavitands to nitrobenzene and other organic and inorganic vapours has been investigated by using the technique of the quartz microbalance (QMB) in order to determine the variation of the mass adsorbed. Cavitands at room temperature showed a high selectivity to nitrobenzene with respect to benzene and other organic vapours like toluene, fluorobenzene and carbon tetrachloride. This material is insensitive towards other vapours, present in a concentration of 1000 ppm, like H-2, CO, SO2, H2S, NO and NO2, and it is also insensitive to relative humidities up to 90%. The X-ray structure analysis of the host-guest complex with the fluorobenzene is also described.