Gas sensitive Langmuir–Blodgett films based on erbium bis[octakis(octyloxy)phthalocyaninato] complex

A new kind of sandwich-like erbium bis[2,3,9,10,16,17,23,24-octakis(octyloxy)phthalocyaninato] complex Er[Pc∗]2 (Pc∗=Pc(OC8H17)8; R=OC8H17) is used as film-forming material. The behaviors of pure Er[Pc∗]2 monolayer and Er[Pc∗]2 and stearic acid-mixed monolayer on pure water and 10−4 M Cd2+ subphases are investigated. Langmuir–Blodgett (LB) films based on Er[Pc∗]2 were deposited onto quartz substrate and planar interdigitated electrode substrate, and the characteristic and gas-sensing property of LB films are studied. It is found that a mixture of 1:6 Er[Pc∗]2/cadmium stearate (CS) forms an excellent material for the fabrication of gas-sensing LB films, giving uniformly deposited multilayers by Y-type deposition, transfer ratio is close to 1. The sensitive property of Er[Pc∗]2/CS mixed LB films to nitrogen dioxide (NO2) gas is monitored by the change of conductivity during gas exposure. Erbium bis[phthalocyaninato] complex-based LB films are very sensitive to the change of NO2 gas. The response time of 11-layer LB film to 100 ppm NO2 is 20 s at room temperature.