Can a highly flexible copper(i) cluster-containing 1D and 2D coordination polymers exhibit MOF-like properties?

Abstract

The reaction of CuI with the highly flexible dithioether ligand p-TolS(CH₂)₈STol-p affords both in MeCN or in EtCN the 2D coordination polymers [Cu₈I₈{p-TolS(CH₂)₈STol-p}₃(solvent)₂]_n (1·MeCN and 1·EtCN) containing octanuclear Cu₈I₈ clusters as connection nodes. In contrast, treatment of CuI with p-tBuC₆H₄S(CH₂)₈SC₆H₄But-p in EtCN solution leads to the formation of the luminescent 1D CP [Cu₄I₄{tBuC₆H₄S(CH₂)₈SC₆H₄-tBu}₂(EtCN)₂]_n (2·EtCN) incorporating Cu₄(μ₃-I)₄ clusters of the closed cubane type as secondary building units (SBUs). The 2D coordination polymers 1·MeCN and 1·EtCN demonstrate the ability to lose their solvent crystallisation molecules under vacuum and readsorb the same or a new one using vapor as monitored by powder X-ray diffraction, thermogravimetric, IR, chromaticity, emission spectra and emission lifetime measurements. Conversely, the 1D material 2·EtCN does not readsorb EtCN, likely due to the collapse of the macrocycles formed by the metal cluster nodes and flexible long-chained ArSC8SAr ligands but absorbs a smaller substrate such as CO₂.