Formation Process of SiF 6 @Cu 2 L 4 Chiral Cage Pairs in a Glass Vessel: Catechol Oxidation Catalysis and Chiral Recognition.

Self-assembly of CuX 2 (X - = BF 4 - , PF 6 - , and SbF 6 - ) with a pair of chiral bidentate ligands, (1 R, 2 S )-(+)- and (1 S, 2 R )-(-)-1-(nicotinamido)-2,3-dihydro-1 H -inden-2-yl-nicotinate ( r,s -L or s,r -L), in a mixture solvent including ethanol in a glass vessel gives rise to SiF 6 2- -encapsulated Cu 2 L 4 chiral cage products. The SiF 6 2- anion from the reaction of X - with SiO 2 of the glass-vessel surface acts as a cage template or cage bridge. One of the products, [SiF 6 @Cu 2 (SiF 6 )( s,r -L) 4 ]·3CHCl 3 ·4EtOH, is one of the most effective heterogeneous catalysts for the oxidation of 3,5-di- tert -butylcatechol. Furthermore, an l -DOPA/ d -DOPA pair is recognizable by the cyclic voltammetry (CV) signals of its combination with chiral cages [SiF 6 @Cu 2 (BF 4 ) 2 ( s,r - or r , s -L) 4 ]·4CHCl 3 ·2EtOH pair and [SiF 6 @Cu 2 (SiF 6 )( s,r - or r,s -L) 4 ]·3CHCl 3 ·4EtOH pair.