Three Sequential Hydrolysis Products of the Ubiquitous Cu₂₄ Isophthalate Metal–Organic Polyhedra

Abstract

Metal-organic polyhedra (MOPs) are increasingly studied as host-guest capsules, linked into networks, or incorporated into composite materials. As such, understanding the decomposition of MOP structures is of fundamental importance. The degradation of the ubiquitous copper(II) MOP Cu₂₄[5-(hydroxy)isophthalate]₂₄ (<b>1</b>) is studied in liquid water. At different intervals of water exposure, powder X-ray diffraction (PXRD) is performed and stepwise conversion of the MOP into three different coordination polymers is observed. First, the formation of a 2D coordination polymer, <b>2</b>, is observed, which upon further exposure gives a 1D coordination polymer, <b>3</b>, and finally a trinuclear copper(II) complex, <b>4</b>. Compound <b>2</b> is characterized by PXRD owing to its transient nature, while <b>3</b> and <b>4</b> are characterized crystallographically. The final structure, <b>4</b>, contains copper(II) trimers, and so its magnetic behavior is also investigated.