Reaction of 2,1,3-benzoselenadiazole (bsd) with AgNO3 results in the formation of a novel model example of a (SeN)-N-... synthon directed molecular network of different polymorphs at different temperatures. alpha-[Ag(bsd)(2)(NO3)](.)0.5bsd formed at ambient temperature, has a 31) 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 (SeN)-N-... synthons. The second polymorph, beta-[Ag(bsd)(2)-(NO3)](.)0(.)5bsd, formed from an analogous reaction at 50 degrees C, contains a similar 3D molecular network constructed with tetrameric [Ag-4(bsd)8(NO3)41 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 (SeN)-N-... interactions.