Supramolecular Synthesis Based on a Combination of Se•••N Secondary Bonding Interactions with Hydrogen and Halogen Bonds

Examination of the solid state structures of 2,1,3-benzoselenadiazole complexes with hydrogen or halogen bond donors has demonstrated that the 2,1,3-benzoselenadiazole molecules preferably form centrosymmetric dimers with use of [Se-N](2) supramolecular synthon, whereas the two remaining nitrogen atoms not involved in the [Se-N](2) supramolecular interactions can act as acceptors of hydrogen or halogen bonds. Cocrystallization of selenadiazoles with monofunctional hydrogen or halogen bond donors like pentafluorophenol, pentafluorobenzoic acid, or pentafluoroiodobenzene results in formation of binary discrete complexes. One- or two-dimensional aggregates based on selenadiazole [Se-N](2) dimers as building blocks were prepared using bifunctional hydrogen or halogen bond donors like resorcinol, tetrafluororesorcinol, tetrafluorohydroquinone, and 1,4-diiodotetrafluorobenzene. During the complexation of selenadiazoles with hydroquinone, anilic acid, or chloranilic acid a competition between Se center dot center dot center dot N and Se center dot center dot center dot O interactions resulted in breaking of the [Se-N](2) synthon.