Synthesis, Characterization, and Catalytic Study of Amine-Bridged Bis(phenolato) Co(II) and Co(II/III)-M(I) Complexes (M = K or Na)
Xinyi He, Yanwei Wang, Dan Yuan*（袁丹）, Hongpeng You, and Yingming Yao*（姚英明）
Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Dushu Lake Campus, Soochow University, Suzhou 215123, People’s Republic of China.
Inorg. Chem.2021, 60, 11521--11529
Co(II) complexes 1–3 bearing amine-bridged bis(phenolato) complexes have been synthesized through reactions of bis(phenols) with CoCl2 or Co(OAc)2. Oxidation of the Co(II) complex with air resulted in partial oxidation, generating mixed valence Co(II/III) complexes 4 and 5. In addition, due to the presence of alkali compounds (KOAc and NaOMe), 4 and 5 formed as Co-alkali metal heterometallic complexes, which are the first example of mixed valence Co(II/III)-M(I) (M = K or Na) complexes. Complexes 1–5 showed good activity in the cycloaddition of epoxides and CO2 under atmospheric pressure, generating cyclic carbonates in 40–99% yields. Co(II/III)-Na(I) complex 5 performed better in reactions of bulkier substrates, underlining the enhanced activity of mixed valence Co-alkali metal heterometallic complexes. On the contrary, complex 5 showed limited activity in copolymerization of epoxide and CO2.
链接：https://pubs.acs.org/doi/abs/10.1021/acs.inorgchem.1c01542