Selective Formation of Small and Large Coordination Cages and Their Catalytic Differences.

Self-assembly of CuX 2 (X - = BF 4 - , ClO 4 - , and CF 3 SO 3 - ) with a new tridentate 5,5',5″-(((2,4,6-trimethylbenzene-1,3,5-triyl)tris(methylene))tris(oxy))triisoquinoline (L) gives rise to single-crystal pairs consisting of small and large cages, [X@Cu 2 X 2 L 4 ]X and [Cu 6 X 12 L 8 ], respectively, via selection of solvents. In particular, the large cage is transformed into a small cage in acetonitrile above 50 °C. A significant difference in heterogeneous catechol oxidation catalysis between the small and large cages is observed. Such notable catechol-oxidation-catalytic effects can be explained by maintenance of the Cu···Cu distance at the catalytic center. This research is a direct systematic example of both cage-size control via solvent selection and the significance of the Cu···Cu distance in catechol oxidation catalysis with copper (Cu).