Publication

Abstract : 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)-N[double bond, length as m-dash]CH-2-C9H6N]3 (2). Crystals of 2 were grown in three different solvent media affording an unsolvated (2, monoclinic, P21/n) and two solvated (2·3H2O, trigonal, R3 and 2·2CH3OH, triclinic, P[1 with combining macron]) 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 2 with Ag(ClO4)2·6H2O in methanol afforded a dinuclear cationic cage [Ag{(S)P[N(Me)-N[double bond, length as m-dash]CH-2-C9H6N]3}·ClO4]2 (3). The molecular structure of 3 reveals a dimeric structure consisting of two AgI ions that are held together by two ligands. Only two arms of the tris hydrazone ligand are involved in coordination while an unprecedented P[double bond, length as m-dash]S→AgI coordination is seen. This results in the formation of an Ag2S2 dimer that is encapsulated by two trishydrazone ligands. Both compounds 2 and 3 are photoluminescent.