Design, Identification, and Evolution of a Surface Ruthenium(II/III) Single Site for CO Activation.

Liqun Kang,Mohsen Danaie,Ke Wu,Ling‐Dong Sun,C Richard A Catlow,Hiroyuki Asakura,Bolun Wang,Adam Thetford,Qian He,Feng Ryan Wang,Emma K Gibson

doi:10.1002/anie.202008370

Abstract

RuII compounds are widely used in catalysis, photocatalysis, and medical applications. They are usually obtained in a reductive environment as molecular O2 can oxidize RuII to RuIII and RuIV. Here we report the design, identification and evolution of an air‐stable surface [bipy‐RuII(CO)2Cl2] site that is covalently mounted onto a polyphenylene framework. Such a RuII site was obtained by reduction of [bipy‐RuIIICl4]− with simultaneous ligand exchange from Cl− to CO. This structural evolution was witnessed by a combination of in situ X‐ray and infrared spectroscopy studies. The [bipy‐RuII(CO)2Cl2] site enables oxidation of CO with a turnover frequency of 0.73×10−2 s−1 at 462 K, while the RuIII site is completely inert. This work contributes to the study of structure–activity relationship by demonstrating a practical control over both geometric and electronic structures of single‐site catalysts at molecular level.

Highlights

RuII complexes were first discovered in the 19th century.[1]
Bipy is a typical chelating ligand that can stabilize metal cations.[14]. It has been functionalized within the UiO-67[15] and polystyrene system recently.[16]
The ratio is set to 1:3 for that raising the content of dibromo molecule will increase the linear content of the polymer, decrease the overall surface area and reduce the accessibility to the bipy sites.[17]

Summary

Introduction

RuII complexes were first discovered in the 19th century.[1] Their chemistry is diverse and has sparked wide interest in homogeneous catalysis,[2] photocatalysis,[3] and biochemical and biomedical applications.[4]. Eleven types of uniform and well-defined surface single sites are obtained, including [bipy-FeCl4]À, [bipy-CoCl2], [bipy-Ni(H2O)4]2+, [bipy-CuCl2], [bipy-Cu(H2O)4]2+, [bipy-ZnCl2], [bipy-RuCl4]À, [bipy-RuBr4]À, [bipy-RhCl4]À, [bipy-PdCl2], and [bipy-PtCl4]. This variety of selection including both metal cations and ligands suggests great potential in catalysis and mechanistic understandings

Results and Discussion

Conclusion

Conflict of interest