Supramolecular isomerism, framework flexibility, unsaturated metal center, and porous property of Ag(I)/Cu(I) 3,3′,5,5′-tetrametyl-4,4′-bipyrazolate

Template-controlled reactions of 3,3',5,5'-tetramethyl-4,4'-bipyrazole (H(2)bpz) with [Ag(NH3)(2)](+) or [Cu(NH3)(2)](+) give binary metal bipyrazolateS [M-2(bpz)] (M = Ag, Cu) as two supramolecular isomers (1 and 2). Isomer 1 possesses four-fold interpenetrated (10,3)-a coordination networks, two-fold interpenetrated (10,3)-a channel networks, and guest-accessible coordinatively unsaturated metal clusters. Isomer 2 possesses eight-fold interpenetrated (6(2)-10)(6-10(2)) coordination networks and isolated, small pores. These metal bipyrazolates are chemically stable and thermally stable up to 300-500 degrees C. Their exceptional framework flexibilities have been demonstrated by adsorption measurements and single-crystal diffraction analyses. The guest-accessible Ag(I)/Cu(I) UMC clusters have also been demonstrated to facilitate the accommodation of unsaturated hydrocarbons such as benzene, toluene, mesitylene, and acetylene via weak metal...pi interactions.