Small-angle X-ray scattering and neutron reflectivity studies of Langmuir–Blodgett films of copper tetra-tert-butyl-azaporphyrines

Langmuir-Blodgett (LB) films of tetra-tert-butyl-substituted copper azaporphyrines, namely phthalocyanine (CuPc'), tetra-3-nitro-phthalocyanine (CuPc*) and porphyrazine (CuPaz'), are studied by small-angle scattering technique. Two kinds of systems are under investigation: first, the CuPc'/Cd-stearate-d₃₅ superlattices; second, the LB films of CuPc', CuPc* and CuPaz' doped with benzene-d₆. X-ray diffraction patterns of the superlattices exhibit bilayer structural units indicating existence of not only 1D but also 3D nano-aggregates of CuPc'. The neutron reflectivity study on the films heavily doped with benzene-d₆ indicates that π-deficiency and size of the azaporphyrine nuclei favor interactions between the nano-aggregates.