Stereospecific interaction of optically active sulfur-bridged dinuclear Co(III)–Pt(II) complex with pseudo-enantiomeric Co(III)–M(II) (M: Pd or Pt) complex involving unequivalent π electronic system

•Assemblies between the pseudo-enantiomers involving unequivalent π electronic system were examined.•Structures of the complexes were determined by single crystal X-ray analyses.•The complexes show stereospecific intermolecular π–π stacking interactions.•The structural characteristics reflect the solid-state spectral behaviors.

Assemblies between the pseudo-enantiomers with different π electronic systems, [Pt(bpy){Co(d-pen)2}]+ (bpy = 2,2′-bipyridine, pen = penicillaminate) and [M(phen){Co(l-pen)2}]+ (M = Pt or Pd, phen = 1,10-phenanthroline), or [Pt(bpy){Co(l-pen)2}]+ and [M(phen){Co(d-pen)2}]+, have been examined from stereo- and spectrochemical aspects. As a result, a mixture of equimolar amounts of optically active sulfur-bridged dinuclear complex, [Pt(bpy){Co(d-pen)2}]Cl, and its pseudo-enantiomer, [M(phen){Co(l-pen)2}]Cl, in H2O crystallizes as [Pt(bpy){Co(d-pen)2}][M(phen){Co(l-pen)2}]Cl2·14H2O, in which two complex cations with imperfect enantiomorphisms form a 1:1 π–π stacked unit. In the crystal, such a 1:1 π–π stacked unit develops into a linear-chain through further π–π stacking contacts with adjacent 1:1 π–π stacked units.

Graphical abstractAssemblies between pseudo-enantiomeric sulfur-bridged dinuclear Co(III)–M(II) (M = Pt or Pd) complexes involving unequivalent π electronic systems have been examined by means of single crystal X-ray analyses, absorption and CD spectra. These pseudo-enantiomeric complexes show stereospecific intermolecular π–π stacking interactions.Figure optionsDownload full-size imageDownload as PowerPoint slide