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

Abstract

Template-controlled reactions of 3,3′,5,5′-tetramethyl-4, 4′-bipyrazole (H2bpz) with [Ag(NH3) 2]+ or [Cu(NH3)2]+ give binary metal bipyrazolates [M2(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 (62.10)(6.102) coordination networks and isolated, small pores. These metal bipyrazolates are chemically stable and thermally stable up to 300-500°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⋯π interactions. © 2008 American Chemical Society.