Pair of (Hg 2 II ) 3 L 2 Chiral Cages and Successive Transformation into (Hg II ) 3 L 2 Chiral Cages: Chiral DOPA Recognition via Chiral Cages.

Self-assembly of Hg(ClO 4 ) 2 with a pair of C 3 -symmetric chiral ligands, (1 S ,1' S ,1″ S ,2 R ,2' R ,2″ R )-(benzenetricarbonyltris(azanediyl))tris(2,3-dihydro-1H-indene-2,1-diyl)trinicotinate ( s , r -L) and (1 R ,1' R ,1″ R ,2 S ,2' S ,2″ S )-(benzenetricarbonyltris(azanediyl))tris(2,3-dihydro-1H-indene-2,1-diyl)trinicotinate ( r , s -L), produces a pair of chiral cages C 4 H 8 O 2 @[(Hg 2 II ) 3 (ClO 4 ) 6 ( s , r -L) 2 (H 2 O) 7 ](C 4 H 8 O 2 ) 7 and C 4 H 8 O 2 @[(Hg 2 II ) 3 (ClO 4 ) 6 ( r , s -L) 2 (H 2 O) 7 ](C 4 H 8 O 2 ) 7 , respectively, via straightforward formation of the reduced Hg 2 II species with an inner cavity in which a single dioxane molecule is nestled. The pair of chiral cages are transformed into their downsized pair of cages, [Hg 3 II (ClO 4 ) 6 ( s , r -L) 2 ] and [Hg 3 II (ClO 4 ) 6 ( r , s -L) 2 ], respectively, in the presence of hydrochloric acid. The original chiral cages are more effective than the corresponding downsized cages for enantiorecognition of chiral 3,4-dihydroxyphenylalanine (DOPA) via the shifts of electrochemical oxidation potentials observed by linear sweep voltammetry (LSV) technique. Furthermore, the photoluminescence (PL) spectral shifts show that the downsized chiral cages significantly recognize chiral DOPA.