Co5C and Co4C carbido carbonyl clusters stabilized by [AuPPh3]+ fragments

Abstract The synthesis and structural characterization of [Co 5 C(CO) 11 (AuPPh 3 ) 3 ], 1 - A and 1 - B , [Co 5 C(CO) 11 (AuPPh 3 ) 2 ] − , 2 , [Co 5 C(CO) 10 (PPh 3 ) 2 (AuPPh 3 )], 3 , [Co 5 C(CO) 12 (AuPPh 3 )], 4 , [Co 5 C(CO) 11 (PPh 3 )(AuPPh 3 )], 5 , and [Co 4 C(CO) 10 (AuPPh 3 ) 2 ], 6 , is herein reported. Compounds 1 – 6 have been obtained whilst studying the reactivity of [Co 6 C(CO) 15 ] 2− with [Au(PPh 3 )Cl] under different experimental conditions, even if better alternative syntheses have been, then, found for some of these new clusters. 1 – 6 contain the electron precise [Co 5 C(CO) 12 ] − , [Co 5 C(CO) 11 ] 3− and [Co 4 C(CO) 10 ] 2− clusters, or their PPh 3 derivatives, stabilized by [AuPPh 3 ] + fragments. Two different isomers of 1 , i.e. , 1 - A and 1 - B , have been found in the solid state due to solvation effects and weak d 10 –d 10 Au(I)⋯Au(I) aurophilic interactions. 1 - A and 4 have been previously described in the literature.