Close Correlation between Metal Oxidation States and Molecular Structures in a Cobalt–Gold Multinuclear Coordination System with Mixed D ‐Penicillaminate and Tripodal Triphosphine

A unique cobalt–gold coordination system, in which the oxidation states of the cobalt centers are closely correlated with the multinuclear molecular structures, is reported. This system contains a Co II 3 Au I 6 nonanuclear structure in [Co 3 {Au 3 (tdme)( D ‐pen‐ N , O , S ) 3 } 2 ] ([ 2 ]) and a Co III Au I 3 tetranuclear structure in [Co{Au 3 (tdme)( D ‐pen‐ N , S ) 3 }] ([ 3 ]) [tdme = 1,1,1‐tris(diphenylphosphinomethyl)ethane, D ‐pen = D ‐penicillamininate], which are stereoselectively prepared from the reaction of a tripod‐type trigold(I) metalloligand [Au 3 (tdme)( D ‐pen) 3 ] 3– ([ 1 ] 3– ) with Co 2+ and Co 3+ , respectively. The anomalous stability of the +II oxidation state of each octahedral cobalt center in [ 2 ], despite the coordination of two aliphatic amine and two aliphatic thiolato groups that commonly provide a strong ligand field, is notable.