Study of Gas Sensing Performances of Langmuir−Blodgett Films Containinig an Alkyne-Linked Conjugated-Porphyrin Dimer

meso,meso‘-Buta-1,3-diyne-bridged Cu(II) octaethylporphyrin dimer thin films have been deposited by the Langmuir−Blodgett method and, for the first time, have been considered as the active layer in conductive gas sensors. In particular, the electrical conductivities of these films undergo a remarkable variation due to exposure to small concentrations of NO in air at an operating temperature of 90 °C. Moreover, such multilayers are substantially unaffected by the contemporary presence in the atmosphere of other gaseous species (NO2, CH4, C2H5OH, CO). To interpret the behavior of such organic films, a mechanism has been developed and proposed, and the conductivity variation as a function of test gas concentrations and time has been derived.