Cleavage of Ru3(CO)12 by N-Heterocyclic Carbenes: Isolation of cis- and trans-Ru(NHC)2(CO)3 and Reaction with O2 To Form Ru(NHC)2(CO)2(CO3)

• Published in: Organometallics 2008-01, Vol.27 (1), p.100-108
• Main Authors: Ellul, Charles E, Saker, Olly, Mahon, Mary F, Apperley, David C, Whittlesey, Michael K
• Format: Article
• Language: English
• ISSN: 0276-7333; 1520-6041
• DOI: 10.1021/om700915t

The N-heterocyclic carbenes (NHCs) 1,3-dialkyl-4,5-dimethylimidazol-2-ylidene (alkyl = ethyl, IEt2Me2; isopropyl, IiPr2Me2) and 1,3-di-isopropylimidazol-2-ylidene (IiPr2) cleave Ru3(CO)12 at room temperature to give the mononuclear complexes Ru(NHC)2(CO)3 (NHC = IEt2Me2 1; IiPr2Me2 2; IiPr2, 3 ). X-ray crystallography reveals that 1 contains trans-NHC ligands whereas 2 and 3 have an unexpected cis arrangement of carbenes. Exposure of 1−3 to air in the solid state or upon reaction with O2 in solution yields the carbonato complexes Ru(NHC)2(CO)2(CO3) (NHC = IEt2Me2 4, IiPr2Me2 5, IiPr2, 6).