CAVITANDS AS SELECTIVE MATERIALS FOR QMB SENSORS FOR NITROBENZENE ANDOTHER AROMATIC VAPORS

The sensitivity of vase-like cavitands to nitrobenzene and other organ ic and inorganic vapours has been investigated by using the technique of the quartz microbalance (QMB) in order to determine the variation o f the mass adsorbed. Cavitands at room temperature showed a high selec tivity to nitrobenzene with respect to benzene and other organic vapou rs like toluene, fluorobenzene and carbon tetrachloride. This material is insensitive towards other vapours, present in a concentration of 1 000 ppm, like H-2, CO, SO2, H2S, NO and NO2, and it is also insensitiv e to relative humidities up to 90%. The X-ray structure analysis of th e host-guest complex with the fluorobenzene is also described.