Post-Synthetic Modification of a 1D Mixed-Linker Zn(II) Coordination Polymer for Acid-Catalyzed Alcoholysis of Epoxides.

Rational design of heterogeneous acid catalysts possessing uniform dispersion of active sites plays a significant role in the catalytic performance. In the present work, a coordination polymer, [Zn(4,4'-bpy)(μ-Hbtc)(HO)] ⋅ 2HO (Zn-CP), was solvothermally synthesized using 4,4'-bpy (=4,4'-bipyridine) and Hbtc (=1,3,5-benzenetricarboxylic acid) mixed linkers. Single crystal X-ray analysis of the polymer displayed that Zn-CP chains were decorated with 4,4'-bpy having unidentate coordination fashion. Then, the free N atom of the linker in Zn-CP was functionalized by -SOH groups to afford Zn-CP-SOH with enhanced acidity. The structures were characterized by FT-IR, thermogravimetric analysis, powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), temperature programmed desorption of NH (NH-TPD), and field emission scanning electron microscopy (FE-SEM) analyses. The coordination polymer was employed as a heterogeneous catalyst for the alcoholysis of epoxides under room conditions. Zn-CP-SOH exhibited excellent catalytic activity and regioselectivity in the methanolysis of styrene oxide within short reaction time.