Tetrahedral Rhenium Cluster Complexes with Mixed-Ligand Cores {Re4As3Q}5+ (Q = S, Se) and {Re4As2S2}6+

Selective Oxidation of Inner Pnictogenide Ligands in Mixed-Ligand Rhenium Cubane-Type Cluster Complexes

Reactivity of new tetrahedral rhenium cluster complexes with pnictogenide inner ligands μ₃-As^3-, μ₃-Sb^3-, and μ₃-Bi^3- has been investigated in reactions with aqueous H₂O₂. It has been found that the oxidation of clusters [{Re₄As₃Q}(CN)₁₂]^7- (Q = S or Se) led to the formation of stable clusters with μ₃-(AsO)^3- ligands. Under the same conditions, the oxidation of [{Re₄As₂S₂}(CN)₁₂]^6- cluster led to substitution of μ₃-As^3- ligands to μ₃-O^2-. The resulting cluster [{Re₄O₂S₂}(CN)₁₂]^4- easily undergoes further oxidation, and even at room temperature, a unique {Re₄} to {Re₃} rearrangement occurs with the formation of the new triangular cluster [{Re₃(μ₃-S)(μ-O)₂(μ-SO₂)}(CN)₉]^5-. Upon heating, this process proceeds faster and the triangular cluster can be isolated as individual compounds. Cluster anions [{Re₄SbSe₃}(CN)₁₂]^5- and [{Re₄BiS₃}(CN)₁₂]^5- reacted with H₂O₂, yielding clusters containing μ₃-O^2- ligands, namely, [{Re₄OSe₃}(CN)₁₂]^4- and [{Re₄OS₃}(CN)₁₂]^4-. This indicates that oxidized forms of μ₃-Sb^3- and μ₃-Bi^3- ligands can be easily substituted.

Heterometallic Re/Mo and Re/W cubane-type cluster complexes

A series of heterometallic Re/Mo and Re/W cubane-type cluster complexes were obtained. New cluster anions demonstrate a regular change in geometric characteristics and redox potentials depending on the composition of the cluster core.

Inorganic Ligands Sb3- and Bi3-: Synthesis and Crystal Structures of Complexes with Mixed-Ligand Cluster Cores {Re4Se3Sb}7+ and {Re4Se3Bi}7

The reactions of ReI₃, Se, and KCN with Sb₂O₃ or Bi₂O₃ at elevated temperature led to the formation of two new tetrahedral clusters with mixed-ligand cluster cores {Re₄Se₃Sb}⁷⁺ and {Re₄Se₃Bi}⁷⁺. They are the first examples of complexes with either Sb^3- or Bi^3- ligands, which have never been previously described in the literature.