Langmuir-Blodgett films of ferrocene derivatives with long alkyl chains

Ferrocene derivatives containing one or two long alkyl chains with a hydrophilic amide or ester linkage were synthesized and monolayers spread on water were investigated by means of pressure-area isotherms. Phase transitions from the expanded to the condensed monolayers were observed. It is suggested that the orientation and packing of ferrocene rings change according to the numbers of long-chain substituents present, and also according to the phase state of the monolayers. Using the Langmuir-Blodgett (LB) method, monolayer assemblies of the ferrocene amide derivative can be obtained; these show a two-dimensional array of the transition metal. UV and IR spectra, together with electrical capacitance measurements on LB films, have given evidence for well-oriented arrangements of the ferrocene derivative. The LB films exhibited a high conductivity, and gave a dielectric constant of 2.9 and on ionization potential of 5.3 eV.