One electron reduction transforms high-valent low-spin cobalt alkylidene into high-spin cobalt(ii) carbene radical†
Abstract
One electron reduction of formally CoIV(OR)2(CPh2) forms the [CoII(OR)2(CPh2)]− anion. Whereas low-spin Co(OR)2(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.