ORGANIZED MOLECULAR FILMS FROM NEW FERROCENE-CONTAINING MOLECULAR UNITS

The design and synthesis of new amphiphilic ferrocene derivatives and their capability for forming Langmuir and Langmuir-Blodgett films are reported. The him formation at the air-water interface was followed by surface pressure-molecular area isotherm, surface potential-molecular area isotherm, and Brewster angle microscopy. The stability and struc ture of the transferred films were investigated by W-vis spectroscopy and small angle X-ray experiments. Transfer ratios near unity were obt ained. Two hydrophobic alkyl chains combined with either one or two hy drophilic functions gave stable and ordered films. One hydrophobic alk yl chain associated to one hydrophilic headgroup required the presence of an intercalant for obtaining organized molecular films. This behav ior clearly illustrated the key role played by the three-dimensional s tructure of the ferrocene unit which tends to decrease the intermolecu lar interactions because of its bulkiness; this is in agreement with r esults reported for ferrocene-containing thermotropic liquid crystals (Deschenaux, R.; Goodby, J. W. In Ferrocenes: Homogeneous Catalysis, O rganic Synthesis, Materials Science; Togni, A., Hayashi, T. Eds.; VCH Verlagsgesellschaft: Weinheim, 1995; pp 471-495).