Enantiospecific electrodeposition of chiral CuO films on Cu(1 1 0) from aqueous Cu(II) tartrate and amino acid complexes

CuO films were anodically electrodeposited onto Cu(1 1 0) single crystals from alkaline solutions of Cu(II) complexed with tartrate, alanine, valine, and glycine. In all cases the films were epitaxial, exhibiting varying amounts of the chiral orientations (1 1 0) and (1¯ 1¯ 0). The enantiomeric excess (ee) of the chiral electrodeposition process was determined by X-ray pole figure analysis. The CuO films deposited from d-tartrate solution exhibited a (1 1 0) out-of-plane orientation with an ee of 61%, while films grown from l-tartrate exhibited a (1¯ 1¯ 0) orientation with an ee of 77%. The CuO film deposited from achiral meso-tartrate had essentially equal amounts of both chiral orientations. Epitaxial CuO films deposited from d-alanine and d-valine both gave (1¯ 1¯ 0) orientation with ee's of 40 and 65%, respectively, while CuO films deposited from l-alanine and l-valine gave (1 1 0) orientations with ee's of 39 and 67%, respectively. Films obtained from a glycine solution showed roughly equal amounts of both chiral orientations.