Studies on an enantiomeric pair of dimeric copper(II) metallomacrocyclic complexes

An enantiomeric pair of [1+2] dimeric copper(II) metallomacrocyclic complexes, (S,S)-1 and (R,R)-2, prepared from the cleavage of Schiff base CN double bonds and ring-degradation of their respective chiral [3+3] macrocyclic ligands, are studied in this paper. X-ray single-crystal diffraction determination for (S,S)-1 and (R,R)-2 reveals that novel dimeric structures are formed where two complementary weak Cu–O coordinative bonds between the formaldehydo O atoms and the copper(II) centers are present and the separations between the dimeric copper(II) centers are 5.546(4) Å in (S,S)-1 and 5.555(3) Å in (R,R)-2. The intrinsic chiral differences of these two copper(II) complexes are demonstrated by their circular dichroism (CD) spectra.

Graphical abstractAn enantiomeric pair of [1+2] dimeric copper(II) metallomacrocyclic complexes (S,S)-1 and (R,R)-2, prepared from the cleavage of Schiff base CN double bonds and the ring-degradation of their respective chiral [3+3] macrocyclic ligands, are studied in this paper.Figure optionsDownload full-size imageDownload as PowerPoint slide