The reaction of the phosphorus trihydrazide, (S)P[N(Me)-NH2]3(1) with quinoline-2-carboxaldehyde (C9H6N-2-CHO) in a 1 : 3 ratio afforded a trishydrazone, (S)P[N(Me)-NCH-2-C9H6N]3(2). Crystals of 2were grown in three different solvent media affording an unsolvated (2, monoclinic, P21/n) and two solvated (2·3H2O, trigonal, R3 and 2·2CH3OH, triclinic, P1) crystal forms. Each of these, while possessing an essentially similar molecular structure, adopt different crystal packing giving rise to supramolecular structures mediated by a variety of weak interactions: O–H–N, O–H–O, C–H–N, C–H–O, C–H–S, C–H–π, π–π, N–π and S–π. The reaction of 2with Ag(ClO4)2·6H2O in methanol afforded a dinuclear cationic cage [Ag{(S)P[N(Me)-NCH-2-C9H6N]3}·ClO4]2(3). The molecular structure of 3reveals a dimeric structure consisting of two AgIions that are held together by two ligands. Only two arms of the tris hydrazone ligand are involved in coordination while an unprecedented PS→AgIcoordination is seen. This results in the formation of an Ag2S2dimer that is encapsulated by two trishydrazone ligands. Both compounds 2and 3are photoluminescent. [ABSTRACT FROM AUTHOR]