Anion-dependent coordinative networking of macrocycle with copper(i) halides

Abstract

An O₂S₂-macrocycle L incorporating three aromatic subunits was synthesized and structurally characterized by X-ray analysis. Four coordination polymers of L with copper(I) halides (Cl, Br and I) adopting different topologies and network patterns depending on the anions are reported. Reactions of L with copper(I) chloride and copper(I) bromide yielded a single-stranded one-dimensional (1D) coordination polymer [CuCl₂(L)(CH₃CN)]_n (1) with an oxidized copper(II) centre and a double-stranded 1D coordination polymer [(Cu₂Br₂)(L)₂]·4CH₂Cl₂]_n (2), with each strand linked by a rhomboid-type Cu₂Br₂ unit. However, the reaction with copper(I) iodide under the same conditions gave an emissive mixture of supramolecular isomers with an identical composition {[Cu₄I₄(L)₂]·CH₂Cl₂}_n, adopting a regular (3a) and a tilted (3b) square-grid-type 2D coordination polymers via cubane-type Cu₄I₄ linking. The XRPD results also confirmed the binary mixture. The conformational diversity in the ligand leads to a variation in overall structural motifs of the supramolecular isomers.