In:
Science Advances, American Association for the Advancement of Science (AAAS), Vol. 6, No. 17 ( 2020-04-24)
Abstract:
CO 2 cycloaddition with epoxides at low temperature and pressure has been broadly recognized as an ambitious but challenging goal, which requires the catalysts to have precisely controlled Lewis acid sites. Here, we demonstrate that both stereochemical environment and oxidation state of single cobalt active sites in cobalt tetraaminophthalocyanine [CoPc(NH 2 ) 4 ] are finely tuned via molecular engineering with 2,5-di-tert-butyl-1,4-benzoquinone (DTBBQ). Notably, DTBBQ incorporation not only enables formation of 5-nm-thick conjugated microporous polymer (CMP) nanosheets due to the steric hindrance effect of tert-butyl groups but also makes isolated cobalt sites with high oxidation state due to the presence of delocalized electron-withdrawing effect of alkene groups in DTBBQ via conjugated skeleton. Notably, when used as heterogeneous catalysts for CO 2 cycloaddition with different epoxides, single cobalt active sites on the ultrathin CMP nanosheets exhibit unprecedentedly high activity and excellent stability under mild reaction conditions.
Type of Medium:
Online Resource
ISSN:
2375-2548
DOI:
10.1126/sciadv.aaz4824
Language:
English
Publisher:
American Association for the Advancement of Science (AAAS)
Publication Date:
2020
detail.hit.zdb_id:
2810933-8
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