Homoleptic and heteroleptic Au(I) complexes containing the new [Co5C(CO)12]− cluster as ligand

The new [{Co5C(CO)12}Au{Co(CO)4}] -, [1]-, cluster has been obtained from the reaction of [Co6C(CO)15]2- with two equivalents of [AuCl4]-. [1]- reacts with an excess of HBF4 resulting in the formation of [{Co5C(CO) 12}2Au]-, [2]-. The new derivatives [Co5C(CO)12(AuPPh3)], 3, and [Co 5C(CO)11(AuPPh3)3], 4, have been obtained by reacting [2]- with two and four equivalents of [Au(PPh3)Cl], respectively. All the new species have been structurally characterised by means of X-ray crystallography as their [NEt 4][1], [NEt4][2], [NMe3(CH2Ph)][2], 3 and 4·thf·0.5C6H14 salts and solvates. [2]- may be viewed as a homoleptic Au(i) complex containing two [Co5C(CO)12]- clusters as ligands. Similarly, [1]- and 3 are heteroleptic Au(i) complexes containing one [Co 5C(CO)12]- cluster ligand as well as [Co(CO)4]- or PPh3. Conversely, 4 contains the [Co5C(CO)11]3- cluster stabilized by three [AuPPh3]+ fragments. [1]- and [2]- have been investigated in solution by means of electrochemical and spectroelectrochemical methods, revealing a very rich redox propensity to form the closely related [1]n- (n = 1-3) and [2]n- (n = 0-3) species. © 2014 the Partner Organisations.The new [{Co5C(CO)12}Au{Co(CO)4}]−, [1]−, cluster has been obtained from the reaction of [Co6C(CO)15] 2− with two equivalents of [AuCl4] −. [1]− reacts with an excess of HBF4 resulting in the formation of [{Co5C- (CO)12}2Au]−, [2]−. The new derivatives [Co5C(CO)12(AuPPh3)], 3, and [Co5C(CO)11(AuPPh3)3], 4, have been obtained by reacting [2]− with two and four equivalents of [Au(PPh3)Cl], respectively. All the new species have been structurally characterised by means of X-ray crystallography as their [NEt4][1], [NEt4][2], [NMe3(CH2Ph)][2], 3 and 4·thf·0.5C6H14 salts and solvates. [2]− may be viewed as a homoleptic Au(I) complex containing two [Co5C(CO)12] − clusters as ligands. Similarly, [1]− and 3 are heteroleptic Au(I) complexes containing one [Co5C(CO)12] − cluster ligand as well as [Co(CO)4] − or PPh3. Conversely, 4 contains the [Co5C(CO)11] 3− cluster stabilized by three [AuPPh3] + fragments. [1]− and [2]− have been investigated in solution by means of electrochemical and spectroelectrochemical methods, revealing a very rich redox propensity to form the closely related [1]n− (n = 1–3) and [2]n− (n = 0–3) species