Removing the sting from the tail: reversible protonation of scorpionate ligands in cobalt(II) tris(carbene)borate complexes |
| |
Authors: | Cowley Ryan E Bontchev Ranko P Duesler Eileen N Smith Jeremy M |
| |
Institution: | Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, New Mexico 88003, USA. |
| |
Abstract: | Low-temperature deprotonation of the phenylborane dications, PhB(RIm)3OTf2 (R = tBu, Mes), followed by in situ reaction with CoCl2(thf)1.5, results in the formation of the four-coordinate complexes, kappa3-PhB(RIm)3CoCl, in which the metal is supported by tripodal N-heterocyclic carbene-based ligands. The chloride complexes are exceptionally sensitive to acid and can be reversibly protonated to form the zwitterions kappa2-{PhB(RIm)2(RIm.H)}CoCl2. This unexpected reactivity is attributed to the highly basic nature of the tris(carbene)borate ligands. Reaction of the chloride complexes with methylating reagents results in products that depend on the N-heterocyclic carbene substituent. For R = tBu, the four-coordinate high-spin complex, kappa3-PhB(tBuIm)3CoMe, is formed, while for R = Mes, reduction to a multitude of complexes occurs. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|