Langmuir-schafer films of an amphiphilic ruthenium complex bearing an "almost naked" multicharcied headgroup

In this paper the preparation and characterization of Langmuir-Schafer (LS) films of a novel amphiphilic dipolar complex, [Ru-II(NH3)(5)(N-dodecyl-4,4'-bpy)](PF6)(3) (1), are reported. Preparation of these films, otherwise precluded utilizing standard Langmuir procedures, is achieved by using a subphase at relatively high ionic strength, by addition of NH4PF6. The morphology and the spectroscopic features of the floating films are investigated by Brewster angle microscopy and UV-vis reflection spectroscopy at the water-air interface, respectively, whereas LS films are characterized by absorption spectroscopy and atomic force microscopy. The overall results indicate the existence of aggregates of 1 and formation of homogeneous, densely packed layers. The presented approach could represent a general method to achieve Langmuir-Blodgett films of amphiphilic metal complexes having an "almost naked" multicharged headgroup.