SURFACE-PLASMON POLARITON STUDIES OF 18-CROWN-6 METAL-FREE PHTHALOCYANINE

In this work surface plasmon resonance studies have been used to chara cterize the response of a thin film of 18-crown-6 metal-free phthalocy anine upon exposure to NO2. The phthalocyanine was deposited by spin c oating onto a gold film which supported the surface plasmon resonance. By fitting angle dependent reflectivity data to the Fresnel theory fo r a range of wavelengths it has been possible to obtain the real and i maginary parts of the optical permittivity of the material over the vi sible part of the spectrum. This procedure has been conducted both bef ore and after exposure to the gas giving an accurate characterization of the changes brought about by the NO2. Thereby the wavelength at whi ch the system's sensitivity to NO2 is an optimum has been calculated. As a secondary measure, the optical parameters derived from the surfac e plasmon resonance experiments have been compared to data obtained by ultraviolet-visible spectroscopy.