Tuning the catalytic activity of the heteronuclear coordination polymers [CoxZn1 − x(tdc)(bipy)] and [CoxZn1 − x(Me2trz–pba)2] in the epoxidation of cyclooctene via isomorphous substitution

Abstract

For two series of isostructural, heteronuclear 3D coordination polymers containing Co and Zn, i.e., [CoxZn1−x(tdc)(bipy)] and [CoxZn1−x(Me2trz–pba)2], with nCo/nZn-ratios from 0.00 to 1.00, the epoxidation of cyclooctene with tert-butyl hydroperoxide in liquid toluene at 348K was studied. In dependence of the Co-content in the material, the catalytic activity steadily increases with the Co-free materials being inactive and the Zn-free materials showing the highest catalytic activity (cyclooctene conversion of 32% and epoxide selectivity of 50%). Although the catalytic conversion occurs at the outer crystallite surface, the results prove that a sensitive tuning of the catalytic properties of coordination polymers and metal-organic frameworks can be achieved by isomorphous substitution with redox active elements.