Supramolecular Self-Assembled Ruthenium−Polypyridyl Framework Encapsulating Discrete Water Cluster

The tecton I [4b,5,7,7a-tetrahydro-4b,7a-epiminomethanoimino-6H-imidazo-[4,5-f]-[1,10]-phenanthroline-6,13-dione] with inherent hydrogen bond acceptor (O atoms) and donor (N−H atoms) groups reacts with cis-Ru(bpy)₂Cl₂ (bpy = 2,2‘-bipyridine) in a 1:1 molar ratio to form a monomeric supramolecular synthon [Ru(bpy)₂(I)]Cl₂ (1), which generates a 3-D metal−organic framework (MOF) by a self-assembly process. The crystal structure reveals an intricate hydrogen-bonding network in which two symmetry-related molecules are connected through N−H···O interactions along with the chlorine anions (C−H···Cl, C−H···O, N−H···Cl, and N−H···O) resulting in the formation of channels. Water clusters buttressed by chlorine anions and fortified by N−H···O and C−H···O interactions are encapsulated within these channels. The reversibile encapsulation of lattice water molecules and the corresponding effect on the overall structure is probed by IR and in situ high-temperature X-ray powder diffraction studies.