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Reactivity of new tetrahedral rhenium cluster complexes with pnictogenide inner ligands μ

A series of heterometallic tetrahedral cluster complexes with the general formula [{MxRe4−xSe4}(CN)12]n− (M = Mo, W; x = 2, 3) were obtained using the reaction of ReI3 and MO3 with selenium and KCN at elevated temperatures. Compounds [ReW3Se4(CN)12]6− and [Re2W2Se4(CN)12]6− are the first rhenium–tungsten heterometallic clusters. Crystal structures, electrochemical properties in aqueous solutions and magnetic properties of crystalline samples have been studied in detail. It has been shown that new cluster anions demonstrate a regular change in geometric characteristics and redox potentials depending on the composition of the cluster core.

The cluster complex (Me4N)K7[{Re4(µ3-CCN)4}(CN)12]·10H2O (I) is synthesized by the high-temperature reaction of ReI3 with KCN and subsequent recrystallization from an aqueous solution with the addition of Me4NI. The anion of complex I contains ligands µ3-CCN3– stabilized due to coordination to the triangular faces of the {Re4} tetrahedral metal cluster. It is shown for [Ni(Еn)2]2+ as an example that the µ3-CCN3– ligands are ambidentate and can interact with transition metal cations similarly to the terminal CN groups, affording the coordination polymer [Ni(En)2(NH3)2][{Ni(En)2}3{Re4(µ3-CCN)4}(CN)12]·7.5H2O (II). The structures of complexes I and II are determined by X-ray diffraction analysis (CIF file ССDС nos. 2057450 (I) and 2057451 (II)).

By a high-temperature reaction of rhenium(III) iodide and red phosphorus with an excess of sodium cyanide followed by recrystallization from an aqueous solution a new tetrahedral [{Re4(PO)4}(CN)12]8– anionic cluster complex is obtained. It is isolated as a salt of the composition Na8[{Re4(PO)4}(CN)12] 18H2O·MeOH. The structure of the obtained compound is determined by X-ray crystallography. The compound crystallizes in the monoclinic crystal system, P21/n space group, unit cell parameters a = 26.826(3) A, b = 11.4975(12) A, c = 29.141(3) A, β = 97.879(2)°, V = 8903.2(16) A3, Z = 8.

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+. Th...

A reaction between ReI3 and KCN at elevated temperature led to the formation of the new cyanometalate cluster anion [{Re4(μ3-CCN)4}(CN)12]8– (1). The anion contains μ3-CCN3– ligands, which are stab...

New tetrahedral anionic rhenium cluster complexes [{Re4(PO)3(PO2)}(CN)12]8- (1) and [{Re4As2(AsO)2}(CN)12]8- (2) have been synthesized by the reaction of ReI3 with NaCN and Pred or KCN and Asgray, respectively. Compound 2 was further oxidized by aqueous H2O2 to produce the cluster anion [{Re4(AsO)4}(CN)12]8- (3). The anions contain new pnictogen/oxygen-based ligands, PO23- and AsO3-, which were stabilized by the coordination to the triangular faces of the tetrahedral Re4 metallocluster in μ3-mode. All three compounds were crystallized as either sodium or potassium salts, and their crystal structures were determined by single crystal X-ray diffraction analysis.

A high-temperature reactions of equimolar amounts of ReI3, As and S or Se with KCN following by recrystallization of the soluble products from water led to the formation of new cyanometallate cluster complexes K7[{Re4As3S}(CN)12]·10H2O (1) and K7[{Re4As3Se}(CN)12]·9.5H2O (2), respectively. Involvement of As2S3 instead of the mixture of As and S resulted in the formation of a cluster complex K6[{Re4As2S2}(CN)12]·3.5H2O (3). Crystal structures of the obtained compounds were investigated by the X-ray diffraction analysis. It was found that compounds 1–3 contain a new cubane cluster cores composed of the rhenium tetrahedron surrounded by the µ3-As and µ3-Q (Q = S, Se) ligands.

A new method is proposed for the one-step synthesis of tetrahedral rhenium chalcocyanide cluster complexes [{Re4(µ3-Q)4}(CN)12]4− (Q = S, Se, Te) using rhenium(iii) iodide as the starting compound. A cluster complex of the composition K4[{Re4S4}(CN)12]•H2O was synthesized for the first time and characterized by X-ray diffraction.

A new method is proposed for the synthesis of the octahedral rhenium chalcocyanide cluster complexes [{Re6(μ3-Q)8}(CN)6]4– (Q = S, Se, Te) using rhenium(IV) oxide as the starting compound. Among the synthesized compounds, the anhydrous cluster salt K4[{Re6Se8}(CN)6] is characterized by X-ray diffraction analysis for the first time. The crystals are orthorhombic, space group Pbcn; a = 13.1386(13), b = 11.4941(8), c = 17.2990(16) A, Z = 4, V = 2612.4(4) A3 (CIF file IСSD no. 434320). The crystal structure of K4[{Re6Se8}(CN)6] represents a framework type packing based on the K+ cations coordinated by the cyanide groups of the cluster anions [{Re6Se8}(CN)6]4–.

The reactions of ReI

Compounds based on new cyanide cluster anions [{Mo6I8}(CN)6]2&ndash, trans-[{Mo6I8}(CN)4(MeO)2]2&ndash, and trans-[{W6I8}(CN)2(MeO)4]2&minus, were synthesized using mechanochemical or solvothermal synthesis. The crystal and electronic structures as well as spectroscopic properties of the anions were investigated. It was found that the new compounds exhibit red luminescence upon excitation by UV light in the solid state and solutions, as other cluster complexes based on {Mo6I8}4+ and {W6I8}4+ cores do. The compounds can be recrystallized from aqueous methanol solutions, besides this, it was shown using NMR and UV-Vis spectroscopy that anions did not undergo hydrolysis in the solutions for a long time. These facts indicate that hydrolytic stabilization of {Mo6I8} and {W6I8} cluster cores can be achieved by coordination of cyanide ligands.

A reaction between ReI

New tetrahedral anionic rhenium cluster complexes [{Re