NDLI: Synergistic oxygen atom transfer by ruthenium complexes with non-redox metal ions

Content Provider	World Health Organization (WHO)-Global Index Medicus
Author	Lv, Zhanao Yin, Guochuan Chen, Zhuqi Zheng, Wenrui Mo, Wanling Tang, Zhiming
Description	Author Affiliation: Lv Z ( Key laboratory of Material Chemistry for Energy Conversion and Storage (Huazhong University of Science and Technology), Ministry of Education, Key laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China. zqchen@hust.edu.cn gyin@hust.edu.cn.)
Abstract	Non-redox metal ions can affect the reactivity of active redox metal ions in versatile biological and heterogeneous oxidation processes; however, the intrinsic roles of these non-redox ions still remain elusive. This work demonstrates the first example of the use of non-redox metal ions as Lewis acids to sharply improve the catalytic oxygen atom transfer efficiency of a ruthenium complex bearing the classic 2,2′-bipyridine ligand. In the absence of Lewis acid, the oxidation of ruthenium(II) complex by $PhI(OAc)_{2}$ generates the Ru(IV)=O species, which is very sluggish for olefin epoxidation. When $Ru(bpy)_{2}Cl_{2}$ was tested as a catalyst alone, only 21.2% of cyclooctene was converted, and the yield of 1,2-epoxycyclooctane was only 6.7%. As evidenced by electronic absorption spectra and EPR studies, both the oxidation of Ru(II) by $PhI(OAc)_{2}$ and the reduction of Ru(IV)=O by olefin are kinetically slow. However, adding non-redox metal ions such as Al(III) can sharply improve the oxygen transfer efficiency of the catalyst to 100% conversion with 89.9% yield of epoxide under identical conditions. Through various spectroscopic characterizations, an adduct of Ru(IV)=O with Al(III), Ru(IV)=O/Al(III), was proposed to serve as the active species for epoxidation, which in turn generated a Ru(III)–O–Ru(III) dimer as the reduced form. In particular, both the oxygen transfer from Ru(IV)=O/Al(III) to olefin and the oxidation of Ru(III)–O–Ru(III) back to the active Ru(IV)=O/Al(III) species in the catalytic cycle can be remarkably accelerated by adding a non-redox metal, such as Al(III). These results have important implications for the role played by non-redox metal ions in catalytic oxidation at redox metal centers as well as for the understanding of the redox mechanism of ruthenium catalysts in the oxygen atom transfer reaction.
ISSN	14779226
Issue Number	28
Journal	Dalton Trans.
Volume Number	45
e-ISSN	13645447
Language	English
Publisher	Royal Society of Chemistry
Publisher Date	2016-07-28
Publisher Place	Great Britain (UK)
Access Restriction	Subscribed
Subject Keyword	Chemistry
Content Type	Text
Resource Type	Article
Subject	Inorganic Chemistry

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in