Synthesis of fluorinated geminal diisocyanides stabilized on a transition metal

Chromium complexes of the geminal diisocyanides bis(pentacarbonyl)-μ-2,2-diisocyano-1,1,1,3,3,3-hexafluoropropane)dichromium 1a and bis(pentacarbonyl)-μ-2,2-diisocyano-1,1,1,3,3-pentafluorobutane)dichromium 1b were obtained by radical alkylation of pentacarbonylcyanochromate besides pentacarbonyl(2-isocyano-1,1,1,3,3,3-hexafluoropropane)chromium 2a and pentacarbonyl(2-isocyano-1,1,1,3,3-pentafluorobutane)chromium 2b, respectively. Pentacarbonyl(2-isocyano-1,1,1,2,3,3,3-heptafluoropropane)chromium 2c was prepared analogously. The crystal and molecular structures of 1a and b were determined by X-ray diffraction.