Thioalkanoates as site-directing nucleating centers for the preparation ofpatterns of CdS nanoparticles within 3-D crystals and LB films of Cd alkanoates

A method is described for the preparation of hybrid organic/inorganic struc tures where the inorganic component comprises semiconductor nanoparticles a ligned in periodic layers within three-dimensional (3-D) crystalline powder s and Langmuir-Blodgett (LB) films. The preparation process comprises the o rganization of metal ions in the form of periodic arrays within 3-D crystal s or the LB films, followed by a topotactic gas/solid reaction. The method is illustrated for the organization of CdS nanoparticles within alkanoic ac ids. The order of the nanoparticles is achieved by introducing site directi ng nucleation centers of Cd thioalkanoates within Cd alkanoates, in the for m of solid solutions. The formed particles are attached to the organic matr ix via -C(O)S-Cd-S- bonds. The structure of those supramolecular architectu res has been characterized by a variety of complementary methods, including transmission electron microscopy (TEM) and electron diffraction (ED), X-ra y powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and oth er spectroscopic measurements.