Thiadiazols take a special place among organic substances because of the variety of their functional groups and ability to react with different chemical compounds. It is known that many thiazols possess biological activities. In this connection, the synthesis and study of the structural parameters of new thiadiazole derivatives are of both scientific and practical interest. Therefore the aim of this work is to determine the structures of N-5-di(pyridin-2-yl)-1,3,4-thiadiazol-2-amine (I) and 5-(5nitrofuran-2-yl)-N-(pyridin-2-yl)-1,3,4-thiadiazole-2-amine (II). These compounds have been obtained as the result of the redox (oxidation-reduction) cyclization of pyridine-2-carbaldehyde 1(pyridin-2-yl)-3-thiosemicarbazone and 5-nitrofuran-2-carbaldehyde 1-(pyridin-2-yl)-3thiosemicarbazone in the presence of silver(I) nitrate and copper(II) nitrate trihydrate, respectively. The both molecules are practically planar. In the crystals they form the centrosymmetric dimmers via intermolecular N-H…N hydrogen bonds. The crystal packing of studied compounds contains the π-π stacking interactions between the thiadiazole and nitrofuran rings in I and the thiadiazole and pyridine rings in II. In I there are also the N—H…π-ring(nitrofuran) interactions between the molecules in the crystal.figureFig. 1. The fragment of the crystal structure I.figureFig. 1. The fragment of the crystal structure II.