Structural Characterization of Organocopper Complexes by EXAFS and XANES: Evidence That Cyanide Does Not Coordinate to Cu in Dimethyl Cuprate Solutions

摘要

The addition of cyanide ion to dialkyl cuprate solutions (e.g. Me_2CuLi) leads to altered reactivity compared to cuprate solutions prepared without cyanide. This effect has been used in hundreds of syntheses and has been ascribed to formation of a three-coordinate Cu--cyanide complex known as a "higher-order" cuprate, 1 (see Figure 1). Recently, the ejastence of a σ-coordinated cyanide in 1 has been questioned. NMR data havs not shown the ~(13)C chemical shift differences expected for a coordinatedcyanide complex.