Molecular Tectonics: Self-Complementary Supramolecular Se···N Synthons Directing Assembly of 1D Silver Chains into 3D Porous Molecular Architectures

Reaction of 2,1,3-benzoselenadiazole (bsd) with AgNO3 results in the formation of a novel model example of a Se···N synthon directed molecular network of different polymorphs at different temperatures. (alpha)-[Ag(bsd)2(NO3)]·0.5bsd formed at ambient temperature, has a 3D porous molecular network constructed with monomeric [Ag(bsd)2(NO3)] motif, and has 1D channels that are encapsulated with 1D arrays of two-fold-disordered dimeric (bsd)2 guests aggregated by the self-complementary nonbonded Se···N interactions. This is the first molecular net directed by supramolecular Se···N synthons. The second polymorph, (beta)-[Ag (bsd)2(NO3)]·0.5bsd, formed from an analogous reaction at 50 °C, contains a similar 3D molecular network constructed with tetrameric [Ag4(bsd)8(NO3)4] motif and 1D arrays of well-ordered dimeric (bsd)2 guests are encapsulated in the channels. Such ordered (bsd)2 dimers provide an excellent simplified dimeric model for MO calculations of intermolecular nonbonded Se···N interactions.