Chromium, Iron and Cobalt Carbonyl Complexes with Gallium Halides: Synthesis and Structures

The reactions of gallium subhalides Ga 2 X 4 · 2dioxane (X = Cl, Br) and “GaI” with carbonylmetallates of chromium, iron and cobalt result in the formation of various gallium halide complexes. These are [(CO) 5 CrGaBr(thf) 2 ] ( 6 ), with a terminal GaX unit, and [(CO) 4 FeGaCl(thf)] 2 ( 1 ), [(CO) 4 FeGaCl 2 Na(thf) 2 ] x ( 2 ), [(CO) 4 FeGaI 2 Na(thf) 3 ] 2 ( 4 ) and [Cr 2 (CO) 8 (GaI 2 )INa 2 (thf) 7 ] x ( 8 ) with GaX units in the bridging positions of gallium–transition‐metal rings. In addition, mixed cyclic gallium–iron hydroxides [{(CO) 4 Fe} 2 Ga 4 Cl 5 (OH) 3 (thf)] 3 and 4 and gallium oxo/hydroxo cages 5 , 9 and 10 were observed. Rings of [{GaCo 4 (CO) 14 }K(thf)] 6 ( 11 ), prepared from Ga 4 Cl 4 R 4 [R = Si(SiMe 3 ) 3 ] and K[Co(CO) 4 ], are connected through isocarbonyl–potassium interactions to form channels. All compounds were characterized spectroscopically and by X‐ray crystallography. DFT calculations were performed on cobalt–gallium complexes to evaluate their bonding properties.