Stereospecific π – π stacking interactions between pseudo-enantiomeric sulfur-bridged dinuclear Co(III)–Pd(II) and Co(III)–Pt(II) complexes with optically active propanediamines.

Assemblies between pseudo-enantiomers with different d8metal centers, Δ-[M(bpy){Co(aet)2(R-pn)}]3+(M = Pd or Pt, bpy = 2,2′-bipyridine, aet = 2-aminoethanethiolate, pn = 1,2-propanediamine), and Λ-[M′(bpy){Co(aet)2(S-pn)}]3+(M′ ≠ M, M′ = Pd or Pt), have been examined from stereo- and spectrochemical aspects. A mixture of equimolar amounts of the optically active sulfur-bridged dinuclear complex, Δ-[M(bpy){Co(aet)2(R-pn)}](NO3)3·7H2O, and its pseudo-enantiomer, Λ-[M′(bpy){Co(aet)2(S-pn)}](NO3)3·7H2O, in H2O crystallizes as [M(bpy){Co(aet)2(R-pn)}][M′(bpy){Co(aet)2(S-pn)}](NO3)6·4H2O, in which two complex cations with imperfect enantiomorphisms form a 1 : 1π–πstacked unit. [ABSTRACT FROM AUTHOR]