Electronic Interactions\nbetween Anchored Molecular\nCatalyst and Support

Immobilizing molecular catalysts on surfaces introduces\nspatial\ncontrol of catalysis and promises improved stability and recyclability\nof the catalyst. The interplays between the support and the immobilized\nmolecular species, however, remain underexplored. Using Ni as a prototypical\nsupport, here we report a study on how the electronic interactions\nbetween the support and the molecular catalyst impacts the reactivity.\nThis work was built upon our previous successes in switching the reactivity\nof iron bis(iminopyridine) alkoxide complexes through redox toggling,\nwhere the anchored iron(II) complex polymerizes lactide, and its cationic\niron(III) counterpart polymerizes epoxides. It was found that Ni as\na metal support could readily oxidize the complex to exhibit catalytic\nactivity toward epoxide polymerization. The charge transfer between\nNi and the Fe complex could be modulated by either electrochemical\nreduction or adding a layer of TiO<sub>2</sub>. The results are expected\nto have major implications for research efforts aimed at converging\nhomogeneous and heterogeneous catalysis.