One electron reduction transforms high-valent low-spin cobalt alkylidene into high-spin cobalt(ii) carbene radical

Amanda Grass; James A Bellow; Gregory Morrison; Hans-Conrad Zur Loye; Richard L Lord; Stanislav Groysman

doi:10.1039/d0cc03028g

One electron reduction transforms high-valent low-spin cobalt alkylidene into high-spin cobalt(ii) carbene radical

Chem Commun (Camb). 2020 Jul 28;56(60):8416-8419. doi: 10.1039/d0cc03028g.

Authors

Amanda Grass¹, James A Bellow¹, Gregory Morrison², Hans-Conrad Zur Loye², Richard L Lord³, Stanislav Groysman¹

Affiliations

¹ Department of Chemistry, Wayne State University, 5101 Cass Ave, Detroit, MI 48202, USA. groysman@chem.wayne.edu.
² Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208, USA.
³ Department of Chemistry, Grand Valley State University, 1 Campus Dr, Allendale, MI 49401, USA. lordri@gvsu.edu.

PMID: 32579653
DOI: 10.1039/d0cc03028g

Abstract

One electron reduction of formally CoIV(OR)2(CPh2) forms the [CoII(OR)2(CPh2)]- anion. Whereas low-spin Co(OR)2([double bond, length as m-dash]CPh2) demonstrated significant alkylidene character, the high-spin [Co(OR)2(CPh2)]- anion features a rare Co(ii)-carbene radical. Treatment of [Co(OR)2(CPh2)][CoCp*2] with xylyl isocyanide triggers formation of two new C-C bonds, and is likely mediated by nucleophilic attack of deprotonated CoCp*2+ on a transient ketenimine.