121st General Meeting of the KCS

Type Poster Presentation
Area Organic Chemistry
Room No. Event Hall
Time 4월 19일 (목요일) 11:00~12:30
Code ORGN.P-494
Subject Fe(II)-polypyridine/iminopyridine Complexes as Efficient Catalysts for the Conversion of CO2 into Cyclic Carbonates
Authors EunYoung Seong, Jae Hyung Kim, Eun Joo Kang*
Department of Applied Chemistry, Kyung Hee University, Korea
Abstract Iron is one of the metals that can convert cyclic carbonates by coupling CO2 and epoxides, there are some studies using a Schiff base1 and an aminophenolate2 based iron complexes. But these complexes limit on modifying tetradentate ligand system, so we investigate new types of Fe-ligand systems based on iminopyridine or polypyridine binding to Fe center in a bidentate or tridentate manner. Notably, Fe(II)-iminopyridine complexes are easy to modify structure in tuning their steric and electronic properties by modification the framework of the ligand. In our reaction condition, Fe(II) complexes have an axial halogen which can be dissociable to form empty site of metal center acting as Lewis acid for epoxide activation. At 60 ℃, relatively low temperature, the combined use of iron complexes and tetrabutyl ammonium bromide (TBAB) resulted in an efficient catalytic system for the synthesis of cyclic carbonates under low CO2 pressure (0.5 MPa) and solvent-free conditions. Fe(II)-polypyridine complexes having their own nucleophilic halide source also converted styrene oxide to cyclic carbonate in the absence of TBAB under the elevated reaction temperature (100 ℃). Particularly, Fe(II) complex bearing bpy-6,6’-diol (dhbpy) ligand showed higher efficiency, suggesting the additional role of hydrogen bonding attraction in epoxide activation. Acknowledgement This study was supported by the Ministry of Education, Science and Technology, National Research Foundation (Grant No. 2017M1A2A2043147 “Next Generation Carbon Upcycling Project”). References 1) G. A. Luinstra et al,; Chem. Eur. J. 2005, 11, 6298–6314. 2) C. J. Whiteoak et al.; Adv. Synth. Catal. 2013, 355, 2233–2239.
E-mail eun920504@naver.com