ИСТИНА

A new, three-dimensional crystalline organic frameworks (F-2 and CF-2) were obtained, linked by hydrogen bonds and additionally stabilized by the opposite charges of the components (Fig. 1). The materials were proved to be an efficient media for stabilizing metal nanoparticles. A new class of palladium nanoparticles encapsulated in the organic crystalline salt matrix Pd@F2 and Pd@CF2 was developed. The matrixes were readily prepared by mixing the dipalladium salt of tetraphenylmethane tetrasulfonic acid and the tetraamine hydrochloride under hydrogen in water. Matrixes Pd@F2 and Pd@CF2 contained 15-20% of palladium and were not pyrophoric. The average size of the palladium metal particles was 7 nm (Pd@F2) and 2 nm (Pd@CF2). The materials could be used as an efficient heterogeneous catalyst for the reduction of acetylene derivatives and had activity similar to that of Pd/C. Pd@F2 reduced the aldehyde and epoxide groups very slowly and allowed the reduction of the acetylene groups to be hydrogenated selectively in the presence of the aldehyde groups. The behavior contrasts with that of Pd/C which reduces both aldehyde and acetylene groups simultaneously. A rational for the behaviour was put forward. Pd@CF2 is being used for asymmetric reduction of double C-C bonds and the reduction of nitrobenzene to aniline