Ring‐opening polymerisation of coordination rings and cages

Despite the great interest in crystalline coordination polymers (sometimes called metal organic frameworks) surprisingly little is known about how they form. However, there has recently been some attention given to characterising their solution‐based precursors. Of particular interest is the formal ring‐opening polymerisation (ROP) relationship between the structures of some precursors and polymers, and the actual observation of ring‐opened oligomers by solution state NMR spectroscopy. These points are highlighted and discussed along with related aspects of isomerism in discrete and polymeric coordination structures, and polymer‐polymer interconversion.