New Molecular Complex 5,6-Dicyano[1,2,5]Selenodiazolo[3,4-b]Pyrazine c 18-Crown-6

Abstract

Slow evaporation of a solution of 5,6-dicyano[1,2,5]selenodiazolo[3,4-b]pyrazine (1) and 18-crown-6 (2) in tetrahydrofuran (THF) yields the 1₄·2₃ THF₂ (3) molecular crystal complex. The composition of 3 differs from the 1:1 stoichiometry typical for molecular complexes of 1,2,5-chalcogenadyazole derivatives with crown ethers. The structure of 3 is determined by single crystal X-Ray diffraction. The crystal packing of 3 is formed by π-stacking interactions between the molecules of 1 and by strongly shortened Se⋯O contacts between the molecules of 1 and 2. The Se⋯O contacts meet the geometric criteria of chalcogen bonding.