Abstract

In search for new conglomerates, seven stereochemically labile complexes between MCl 2 (M = Co, Cu, Ni, Zn) and bidentate ligands, the commercially available N, N, N′-trimethylethane-1,2-diamine (trimeda) and the somewhat bulkier N-isopropyl- N, N′, N′-trimethylethane-1,2-diamine (itmeda), have been synthesized and characterized using single crystal X-ray diffraction. The trimeda and itmeda ligands exhibit chirogenic nitrogen centers and may form chiral metal complexes that are candidates for total spontaneous resolution. Copper(II) chloride forms the dimeric meso complexes [{CuCl 2(trimeda)} 2] ( 1) and [{CuCl 2(itmeda)} 2] ( 2), while [CoCl 2(trimeda) 2] ( 3) and [NiCl 2(trimeda) 2] ( 4) exhibit six-coordinate but chiral ( R, R)- and ( S, S)-complexes. Three examples of the chiral target complex, comprising four-coordinate stereochemically labile monomers, was successfully prepared, viz. [NiCl 2(itmeda)] ( 5), [ZnCl 2(itmeda)] ( 6), and [CoCl 2(itmeda)] ( 7). In all seven complexes, the λ-conformation of the five-membered trimeda-metal chelate ring corresponds to the ( S)-configuration at nitrogen, and vice versa. Supramolecular interactions in 3 and 4 form hydrogen-bonded heterochiral ribbons. However, crystals of 5– 7 display homochiral interactions resulting in polar phases. Weak CH–Cl interactions in 5 and 6 form homochiral layers. In 7, interactions form homochiral helices along the a-axis.

Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call