Reactivity of a low-valent chromium dinitrogen complex

• Published in: Inorganica Chimica Acta 2011-04, Vol.369 (1), p.103-119
• Main Authors: Monillas, Wesley H., Yap, Glenn P.A., Theopold, Klaus H.
• Format: Article
• Language: English
• Subjects: Bond cleavage; Chromium; Crystal structures; Nitrogen complex; β-Diketiminates
• ISSN: 0020-1693; 1873-3255
• DOI: 10.1016/j.ica.2010.11.024

The chromium dinitrogen complex (Nn −iPrCr) 2(μ 2-κ 2:κ 2-N 2) is a readily accessible Cr(I) synthon. Its substitutional lability and great reducing power facilitate the binding and activation of a wide range of organic molecules. [Display omitted] ► A dinuclear Cr(I) dinitrogen complex ( 1) is a reactive low-valent chromium synthon. ► Compound 1 couples ketones and imines. ► Compound 1 cleaves single and multiple heteroatom bonds. (Nn iPrCr) 2(μ 2-κ 2:κ 2-N 2) ( 1, Nn iPr = bis(2,6-diisopropylphenyl)pentane-2,4-ketiminato), formally a chromium(I) complex, was exposed to a variety of small molecules possessing hetero- or homo-atomic single, double, or triple bonds. Reaction of 1 with adamantyl azide yielded complexes in various higher oxidation states, such as (Nn iPrCr II) 2(μ 2-NAd) ( 2), Nn iPrCr III(κ 2-N 4Ad 2) ( 3), or Nn iPrCr V(NAd) 2 ( 4). Compound 1 was found to reductively couple 3-pentanone to form Nn iPrCr(κ 2-O 2C 2Et 4) ( 5) and reductively couple benzylidene aniline to form both Nn iPrCr III( cis-κ 2-C 28H 22N 2) ( 6a) an Nn iPrCr III( trans-κ 2-C 28H 22N 2) ( 6b). Reaction with a stochiometric amount of benzylidene aniline yielded the imine complex Nn iPrCr(η 2-NPhCHPh) ( 7). Exposure of 1 to a bulky isocyanide formed the octahedral Nn iPrCr I[CN(C 6H 4(Me) 2] 4 ( 9). Complex 1 was also found to break the O–O, N O, and S–S bonds in various small molecules to form Nn iPrCr II(OCMe 3) ( 11), Nn iPrCr V(O)(NPh) ( 8), and [Nn iPrCr II(μ-SPh)] 2 ( 10).