Structural diversity of homochiral cadmium-camphorates with 2,2'-bipyridine

摘要

Homochiral framework materials are of current interest due to their potential applications in asymmetric catalysis and enantioselective separation. Four new Cd(II) camphorates (1—4) with 2,2'-bipyridine ligand (= 2,2'-bipy) are successfully synthesized and show distinct structural features. Such rich Cd-cam-2,2'-bipy system is composed of four compounds, [Cd(D-cam)(2,2'-bipy)(DMF)]_n (1), [Cd(D-cam)(2,2'-bipy) (H_2O)]_n (2), [Cd_2(D-cam)_2(2,2'-bipy)2]_n (3) and [Cd_2Cu_2(D-cam)_4(2,2'-bipy)2]_n-4nH_2O (4), which are obtained under different conditions. Both compounds 1 and 2 show infinite homochiral Cd-camphorate chain, while compounds 3 and 4 exhibit homochiral layered structures based on different dinuclear units. The results demonstrate the rich coordination chemistry of the enantiopure D-camphorate ligand and the structural diversity of metal-camphorate compounds.