Reactions of bromine-bridged cobalt bis(1,2-dicarbollide) anion with arenes and nucleophiles

Abstract The generation of Br-bridged complex of cobalt bis(1,2-dicarbollide) (8,8′-μ-Br-3,3′-Co(1,2-C 2 B 9 H 10 ) 2 ) and its reactions with arenes and some nucleophiles were studied. The complex 8,8′-μ-Br-3,3′-Co(1,2-C 2 B 9 H 10 ) 2 can be generated in situ via the action of 8-monobromo derivative of cobalt bis(1,2-dicarbollide) and AlX 3 (X = Cl, Br) in different aromatic solvents. This unstable complex was characterized by 11 B NMR spectroscopy for the first time. Its reactions with an appropriate arene led to [8-Br-8′-Ar-3,3′-Co(1,2-C 2 B 9 H 10 ) 2 ] - species even without addition of an activating Lewis base. Reactions of 8,8′-μ-Br-3,3′-Co(1,2-C 2 B 9 H 10 ) 2 with S- and N -nucleophiles (thioxane, morpholine) in benzene afforded the corresponding charge-compensated derivatives (8-Br-8′-Y-3,3′-Co(1,2-C 2 B 9 H 10 ) 2 ) as well as [8-Br-8′-Ar-3,3′-Co(1,2-C 2 B 9 H 10 ) 2 ] - species.