Three cationic metal-organic frameworks (MOFs), Ag(btr).PF6.0.5CH(3)CN (1), Ag-2(btr)(2)(H2O).2CF(3)SO(3).H2O (2), and Ag-2(btr)(2)(NO3).NO3 (3), were prepared from reaction of 4,4'-bis(1,2,4-triazole) (btr) with silver salts containing different anions. Complex 1 is a three-dimensional (3-D) framework constructed from tetrahedral-shaped nanoscale coordination cages with PF6- as counteranions. 2 and 3 are 3-D architectures containing 1-D channels, in which charge-balancing CF3SO3- and NO3- are located in their respective channels. Luminescent emission of 1-3 shows an obvious red shift compared with the btr ligand. Anion exchange studies show that 1 is able to selectively exchange MnO4- in aqueous solution with a modest capacity of 0.56 mol mol-(1); the luminescent emission of 1 is quickly quenched upon MnO4- exchange.