Accessing Three Oxidation States of Cobalt in M6L3 Nanoprisms with Cobalt-Porphyrin Walls

Nanocages with porphyrin walls are common, but studies of such structures hosting redox-active metals are rare. Pt-linked M6L3 nanoprisms with cobalt-porphyrin walls were prepared and their redox properties were evaluated electrochemically and chemically, leading to the first time that cobalt-porphyrin nanocages have been characterized in Co(I), Co(II), and Co(III) states.

Electroreduction of Carbon Dioxide by Heterogenized Cofacial Porphyrins

Great attention has been paid to cofacial porphyrins due to their many unique advantages over their monomeric analogs. However, their synthesis is usually complicated. In this work, a facile impregnation method for preparing heterogenized, cofacially stacked porphyrins is proposed. An anionic porphyrin is introduced as an underlayer for immobilization of cationic cobalt porphyrin via electrostatic force. The metal center of the underlying molecule contributes to the electronic structure of the upper cationic cobalt porphyrin. Screening reveals the anionic iron porphyrin to be the most efficient underlayer molecule, lowering the activation energy barrier of CO2 electroreduction, with an improved turnover frequency by 74% to 8.0 s−1 at − 0.6 V versus RHE.