Amine-bis(phenolato)cobalt(II) Catalysts for the Formation of Organic Carbonates from Carbon Dioxide and Epoxides

作者：Reiter Marina; Altenbuchner Peter T; Kissling Stefan; Herdtweck Eberhardt; Rieger Bernhard^*

来源：European Journal of Inorganic Chemistry, 2015, 2015(10): 1766-1774.

DOI：10.1002/ejic.201403087

• Carbon dioxide fixation
• Copolymerization
• Cyclic carbonates
• Epoxides
• Cobalt

New monometallic amine-bis(phenolato)cobalt(II) [(ONNO)Co-R(II)] (R = CMe2Ph; Cl; Br) complexes have been synthesized and fully characterized including X-ray crystallographic analysis. These Co-II complexes show good activity for the formation of cyclic propylene carbonate in combination with tetrabutylammonium bromide (TBAB) as a co-catalyst. The reaction parameters such as carbon dioxide pressure, co-catalyst loadings and temperature were varied to determine the ideal reaction conditions. These catalysts were also employed in copolymerization reactions of cyclohexene oxide/CO2 and propylene oxide/CO2. [(ONNO)Co-Cl(II)]*(MeOH) was found to effectively copolymerize cyclohexene oxide (CHO) and CO2. This is the first reported amine-bis(phenolato) cobalt(II) complex to be active in the copolymerization of CO2 and CHO. In-depth stability studies were conducted (Evan's method) to validate Co-II as the active species required for copolymerization. End-group analysis via NMR, ESI-MS and MALDI-TOF revealed the presence of 4-(dimethylamino)pyridine (DMAP) and methoxy terminated chains.

• 出版日期2015-4