Organometallic Sulfur Group Elements Carborane Chemistry Research

We studied the reactions of dilithium dichalcogenolate carborane compounds [(THF)₃LiE₂C₂B₁₀H₁₀(THF)]₂ [E = S, Se, Te], which act as bidentate ligands, with half-sandwich transition metal complexes of molybdenum, cobalt and vanadium. The research contained the following four sections.1. Tridentate mononuclear hydrotris(3,5-dimethyl-l-pyrazolyl)borate molybdenum (V) complex {HB(Me₂Pz)₃}Mo(O)Cl₂ (1) reacted with 1/2 equivalent of [(THF)₃LiE₂C₂B₁₀H₁₀(THF)]₂ [E = S (2a), Se (2b), Te (2c)] with the replacement of both chloride ligands to give bidentate complexes {HB(Me₂Pz)(Me₂Pz)₂}Mo(O)E₂[C₂(B₁₀H₁₀)] [E = S(3a), Se(3b), Te(3c)]. The molecular structures of 3b, 3c were characterized by X-ray crystallographic analysis. 3a can convert to novel binuclear molybdenum complex {HB(Me₂Pz)₃Mo(O)(μ₂-O)2Mo(O)S₂C₂B₁₀H₁₀}(Me₂PzH) ₄ when it was oxided in air. X-ray structure analysis indicated that Mo-Mo existed strong interaction(d_Mo-Mo = 2.5483(12) A).2. The "pseudo-aromatic" 16-electron half-sandwich complexes Cp/CoE₂C₂B₁₀H₁₀ (Cp = Cp^t, Cp^tt, E = S, Se) have been synthesized by the reactions of C/Co(CO)I₂ with [(THF)₃LiE₂C₂B₁₀H₁₀(THF)]₂ in Et₂O/THF at room temperature. X-ray structure analysis indicated that the five-membered rings of CoE₂C₂ are planner and hold "pseudo-aromatic"charactistics.3. The hetero-dinuclear complexes Cp^ttCoM(CO)₂(Se₂C₂B₁₀H₁₀)₂(M = Mo, W) were obtained from the reactions of complex Cp^ttCoE₂C₂B₁₀H₁₀ (E = S, Se) with low-valence transition metal complex M(CO)₃(py)₃ (M= Mo, W py = pyrindine) and BF₃·Et₂O (2:1 in molar ratio) in Et₂O at room temperature. The molecular geometry of Cp^ttCoW(CO)₂(Se₂C₂B₁₀H₁₀ )₂ was determined by X-ray structural analysis. X-ray structure analysis indicated that Co-W existed strong interactions(d_co-w = 2.705(2) A).4. VC1₃(1) reacted with Li₂E₂C₂B₁₀H₁₀(E = S(2a), Se(2b)) in THF/Et₂O to afford bi-nuclear complexes {(THF)₃LiOV[E₂C₂(B₁₀H₁₀)]}₂(E = S(3a), Se(3b)). The molecular geometry of {(THF)₃LiOV[S₂C₂(B₁₀H₁₀)]}₂ was determined by X-raystructural analysis. X-ray structure analysis indicated that V-V existed strong interactions(d_v-v = 1.641(3) A, which is called "super short bond")...