Discrete and infinite cage-like frameworks with inclusion of anionic and neutral species and with interpenetration phenomena

Complex [Ag(tpba)N-3] (1) was obtained by reaction of novel tripodal ligand N,N',N"-tris(pyrid-3-yl-methyl)-1,3,5-benzenetricarboxamide (TPBA) with [Ag(NH3)(2)]N-3. While the reactions between 1,3,5-tris(imidazol-1-ylmethyl)-2,4,6-trimethylbenzene (TITMB) and silver(i) salts with different anions and solvent systems give six complexes: [Ag-3(titmb)(2)](N-3)(3)(CH3O)-C-.- H(.)4H(2)O (2), [Ag-3(titmb)(2)](CF3SO3)(2)(OH)(.)5H(2)O (3), [Ag-3(titmb)(2)][Ag(NO3)(3)](NO3H2O)-H-. (4), [Ag-3(titmb)(2)(py)](NO3)(3)(H2O)-H-. (py=pyridine) (5), [Ag-3(titmb)(2)(py)](ClO4)(3) (6), and [Ag-3-(titmb)(2)](ClO4)(3) (CHCl3)-C-. (7). The structures of these complexes were determined by X-ray crystalography. The results of structural analysis of complexes 1 and 2, with the same azide anion but different ligands, revealed that 1 is a twofold interpenetrated 3D framework with interlocked cage-like moieties, while 2 is a M,L, type cage-like complex with a methanol molecule inside the cage. Entirely different structure and topology between 1 and 2 indicates that the nature of organic ligands affected the structures of assemblies greatly. While in the cases of complexes 2-7 with flexible tripodal ligand TITMB, they are all discrete M3L2 type cages. The results indicate that the framework of these complexes is predominated by the nature of the organic ligand and geometric need of the metal ions, but not influenced greatly by the anions and solvents. It is interesting that there is a divalent anion [Ag(NO3)(3)](2-) inside the cage 4 and an anion of ClO4- or NO3- spontaneously encapsulated within the cage of complexes 5, 6 and 7.