Metal-organic organopolymeric hybrid framework by reversible [2+2] cycloaddition reaction

Organic polymers are usually amorphous or possess very low crystallinity. The metal complexes of organic polymeric ligands are also difficult to crystallize by traditional methods because of their poor solubilities and their 3D structures can not be determined by single-crystal X-ray crystallography owing to a lack of single crystals. Herein, we report the crystal structure of a 1D Zn^II coordination polymer fused with an organic polymer ligand made insitu by a [2+2] cycloaddition reaction of a six-fold interpenetrated metal-organic framework. It is also shown that this organic polymer ligand can be depolymerized in a single-crystal-to-single-crystal (SCSC) fashion by heating. This strategy could potentially be extended to make a range of monocrystalline metal organopolymeric complexes and metal-organic organopolymeric hybrid materials. Such monocrystalline metal complexes of organic polymers have hitherto been inaccessible for materials researchers. Make or break: A 3D structure consisting of an organic polymer containing cyclobutane rings blended with a Zn^II coordination polymer was obtained through a photochemical polymerization reaction. Monocrystalline metal complexes of organic polymer ligands are hitherto unknown. The organic polymer can be depolymerized by cleavage of the cyclobutane rings in a single-crystal-to-single-crystal manner.