{"title":"Calix[8]arene-Based Manganese Complexes for Electrocatalytic CO2 Reduction","authors":"Armando Berlanga-Vázquez, Ivan Castillo","doi":"10.1002/ijch.202300083","DOIUrl":null,"url":null,"abstract":"<p>Transition metal catalysts with modified second-coordination sphere employed in the electrocatalytic CO<sub>2</sub> can result in increased activity or directed product selectivity. Calixarenes can form metal complexes and potentially catalyze reactions within its cavity, taking advantage of the surrounding phenols groups to tune the reactivity by second-coordination sphere effects. Here, we present a Mn(I) bromotricarbonyl complex with phenanthroline-functionalized calix[8]arene ligands capable of electrocatalytically reducing CO<sub>2</sub> into different products with 2,2,2-trifluoroethanol as proton donor. The selectivity of the reaction seems to be affected by the calixarene cavity: two calixarene-free analogous complexes reduce CO<sub>2</sub> to CO almost exclusively, while the calixarene complexes produce primarily CO, H<sub>2</sub>. Interestingly, in some cases the less frequently observed CH<sub>4</sub> was also detected, albeit with low Faradaic efficiency. Thus, the manganese center placed within the calixarene cavity promotes the formation of reduced CO<sub>2</sub> products by more than two electrons and two protons, affording CH<sub>4</sub> in some cases.</p>","PeriodicalId":14686,"journal":{"name":"Israel Journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":2.3000,"publicationDate":"2023-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ijch.202300083","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Israel Journal of Chemistry","FirstCategoryId":"92","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/ijch.202300083","RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Transition metal catalysts with modified second-coordination sphere employed in the electrocatalytic CO2 can result in increased activity or directed product selectivity. Calixarenes can form metal complexes and potentially catalyze reactions within its cavity, taking advantage of the surrounding phenols groups to tune the reactivity by second-coordination sphere effects. Here, we present a Mn(I) bromotricarbonyl complex with phenanthroline-functionalized calix[8]arene ligands capable of electrocatalytically reducing CO2 into different products with 2,2,2-trifluoroethanol as proton donor. The selectivity of the reaction seems to be affected by the calixarene cavity: two calixarene-free analogous complexes reduce CO2 to CO almost exclusively, while the calixarene complexes produce primarily CO, H2. Interestingly, in some cases the less frequently observed CH4 was also detected, albeit with low Faradaic efficiency. Thus, the manganese center placed within the calixarene cavity promotes the formation of reduced CO2 products by more than two electrons and two protons, affording CH4 in some cases.
在电催化 CO2 中使用具有改性第二配位层的过渡金属催化剂可以提高活性或定向产品选择性。六碳烯可以形成金属配合物,并有可能在其空腔内催化反应,利用周围的酚基,通过第二配位层效应来调节反应活性。在此,我们介绍了一种具有菲罗啉功能化钙[8]烯配体的溴羰基锰(I)配合物,该配合物能够以 2,2,2-三氟乙醇为质子供体,通过电催化将 CO2 还原成不同的产物。反应的选择性似乎受到钙[8]烯空腔的影响:两种不含钙[8]烯的类似配合物几乎只将 CO2 还原成 CO,而钙[8]烯配合物则主要生成 CO 和 H2。有趣的是,在某些情况下还能检测到不太常见的 CH4,尽管法拉第效率较低。因此,放置在钙铝烯烃空腔中的锰中心通过两个以上的电子和两个质子促进了还原 CO2 产物的形成,在某些情况下产生了 CH4。
期刊介绍:
The fledgling State of Israel began to publish its scientific activity in 1951 under the general heading of Bulletin of the Research Council of Israel, which quickly split into sections to accommodate various fields in the growing academic community. In 1963, the Bulletin ceased publication and independent journals were born, with Section A becoming the new Israel Journal of Chemistry.
The Israel Journal of Chemistry is the official journal of the Israel Chemical Society. Effective from Volume 50 (2010) it is published by Wiley-VCH.
The Israel Journal of Chemistry is an international and peer-reviewed publication forum for Special Issues on timely research topics in all fields of chemistry: from biochemistry through organic and inorganic chemistry to polymer, physical and theoretical chemistry, including all interdisciplinary topics. Each topical issue is edited by one or several Guest Editors and primarily contains invited Review articles. Communications and Full Papers may be published occasionally, if they fit with the quality standards of the journal. The publication language is English and the journal is published twelve times a year.