Chiral Scrambling and Independent Crystallization of d 4, l 4, and d 2 l 2 Isomers of an AuI 4CoIII 2 Hexanuclear Complex with Mixed Penicillaminate and Bis(diphenylphosphino)ethane

The 1:1 mixing of a pair of enantiomers of a cyclic AuI 4CoIII 2 hexanuclear complex having penicillaminate (pen) and 1,2-bis­(diphenylphosphino)­ethane (dppe), [Au4Co2(dppe)2(d-pen)4]2+ (d 4-[1]2+) and [Au4Co2(dppe)2(l-pen)4]2+ (l 4-[1]2+), in solution produced an additional stereoisomer, [Au4Co2(dppe)2(d-pen)2(l-pen)2]2+ (d 2 l 2-[1]2+), because of the scrambling of [Co­(d-pen)2]− and [Co­(l-pen)2]− units between d 4-[1]2+ and l 4-[1]2+. Upon crystallization with NO3 –, the three stereoisomers were independently crystallized to form three different kinds of crystals, homochiral crystals of d 4-[1]­(NO3)2, homochiral crystals of l 4-[1]­(NO3)2, and heterochiral crystals of d 2 l 2-[1]­(NO3)2, showing a unique example of the self-recognition and organization of three stereoisomers upon crystallization.