Synthesis, structure and chiroptical study of chiral macrocyclic imine nickel(II) coordination compounds derived from camphor.

A couple of enantiomers of novel chiral macrocyclic imines based on R/S-camphor were asymmetrically synthesized. Through the chiral macrocyclic ligands, enantiomers of nickel(II) coordination compounds were obtained. The chirality of the ligand was transferred to the nickel atom upon coordination, leading to predetermined configuration. The chiral ligands and corresponding nickel coordination compounds were characterized by UV, IR, CD, VCD spectra and single crystal X-ray crystallography. The structural and spectroscopic properties were further investigated by DFT calculations.