Understanding the Origin of the Chiral Recognition of Esters with Octahedral Chiral Cobalt Complexes

Abstract

Here, we report a combined experimental and computational study to understand the chiral recognition of cationic cobalt complexes with esters. The cationic cobalt complexes were synthesized by stereoselective assembly of ligands to the cobalt center. The tetradentate N2O2 ligand was used to control the metal-centered chirality, and the bidentate diamine ligand played an important role in the chiral discrimination of esters by H-1 NMR spectroscopy. The phenyl rings of the cobalt complexes additively enhanced the chiral discrimination. The opposite chiralities of the N2O2 ligand and bidentate diamine ligand constituted a well-matched combination, which was further demonstrated by computational analysis of 1 : 2 binding models of the cationic cobalt complex and 1-phenylethyl acetate.