Cotton F. Albert, Dikarev Evgeny V., Petrukhina Marina A.
Laboratory for Molecular Structure and Bonding, P.O. Box 300012, Department of Chemistry, Texas A&M University, College Station, Texas 77842-3012.
Inorg Chem. 1998 Nov 16;37(23):6035-6043. doi: 10.1021/ic980701l.
The interaction between octachlorodirhenium anions and diethylphosphine has been shown to strongly depend on reaction conditions, mainly the nature of the solvent and the amount of phosphine. As a result, novel dirhenium products with oxidation states ranging from Re(II) to Re(IV) have been obtained. The reaction of Re(2)Cl(8)(-) with an excess of PEt(2)H in dichloromethane or acetonitrile led to the first example of a face-sharing complex of rhenium(IV) with three phosphido-bridges, namely [Bu(n)(4)N][Re(2)(&mgr;-PEt(2))(3)Cl(6)] (1). The unusual edge-sharing Re(2)(&mgr;-PEt(2))(2)Cl(4)(PEt(2)H)(4) (2) complex of rhenium(III) with C(i)() core symmetry, containing both terminal phosphines and phosphido-bridges, has been obtained by carrying out the reaction with an excess of PEt(2)H in a benzene (or propanol) - HCl mixture at room temperature. A new example of the 1,2,7,8-type of dirhenium(II) complex, Re(2)Cl(4)(PEt(2)H)(4) (3), having diethylphosphine ligands located cis on each Re atom, has been isolated from the reaction of Re(2)Cl(8)(-) with PEt(2)H in an ethanol-HCl medium. The solid-state structures of complexes 1-3 have been investigated by X-ray crystallography. Complexes 1 and 2 both crystallized in two forms: [Bu(n)(4)N][Re(2)(&mgr;-PEt(2))(3)Cl(6)] 1a, P2(1)/n with a = 10.482(1) Å, b = 16.512(2) Å, c = 23.986(2) Å, beta = 93.637(8) degrees, and Z = 4; [Bu(n)(4)N][Re(2)(&mgr;-PEt(2))(3)Cl(6)].1.5 C(7)H(8) 1b, C2/c with a = 38.746(9) Å, b = 10.322(2) Å, c = 27.277(3) Å, beta = 110.35(1) degrees, and Z = 8; Re(2)(&mgr;-PEt(2))(2)Cl(4)(PEt(2)H)(4) 2a, P2(1)/n with a = 11.081(3) Å, b = 11.029(3) Å, c = 15.627(2) Å, beta = 90.05(1) degrees, and Z = 2; 2b, P2(1)/c with a = 16.094(3) Å, b = 15.193(3) Å, c = 15.548(3) Å, beta = 100.98(3) degrees, and Z = 4. X-ray data for complex Re(2)Cl(4)(PEt(2)H)(4) 3 are as follows: P2(1)/n with a = 10.445(2) Å, b = 10.113(3) Å, c = 13.473(2) Å, beta = 102.17(2) degrees, and Z = 2. Three bridging &mgr;-PEt(2) groups in the face-sharing complex 1 span a short metal-metal distance of 2.4060(6) Å, averaged over 1a and 1b, with a small Re-PEt(2)-Re angle of 61.34(7) degrees. The rhenium-rhenium bond length in the edge-sharing complex 2 is 2.7545(7) Å, averaged over 2a and 2b, while the bridging Re-PEt(2)-Re angle is 72.16(6) degrees, and the P-Re-P angle for the terminal phosphine ligands is 87.11(7) degrees. The Re-Re bond distance in 3, 2.2533(8) Å, is typical for triply bonded dirhenium complexes, and the P-Re-P angle for the cis phosphine groups is 93.12(6) degrees.
八氯二铼阴离子与二乙膦之间的相互作用已被证明强烈依赖于反应条件，主要是溶剂的性质和膦的用量。结果，获得了氧化态范围从Re(II)到Re(IV)的新型二铼产物。[Re₂Cl₈]²⁻与过量的PEt₂H在二氯甲烷或乙腈中反应，得到了第一个铼(IV)与三个磷桥的面共享配合物的例子，即[Buₙ₄N][Re₂(μ - PEt₂)₃Cl₆] (1)。通过在室温下于苯（或丙醇） - HCl混合物中与过量的PEt₂H进行反应，获得了具有Cᵢ对称性的铼(III)的不寻常的边共享Re₂(μ - PEt₂)₂Cl₄(PEt₂H)₄ (2)配合物，其同时含有末端膦和磷桥。从[Re₂Cl₈]²⁻与PEt₂H在乙醇 - HCl介质中的反应中分离出了一种新的1,2,7,8型二铼(II)配合物Re₂Cl₄(PEt₂H)₄ (3)，其在每个Re原子上的二乙膦配体位于顺式位置。通过X射线晶体学研究了配合物1 - 3的固态结构。配合物1和2均以两种形式结晶：[Buₙ₄N][Re₂(μ - PEt₂)₃Cl₆] 1a，P2₁/n，a = 10.482(1) Å，b = 16.512(2) Å，c = 23.986(2) Å，β = 93.637(8)°，Z = 4；[Buₙ₄N][Re₂(μ - PEt₂)₃Cl₆]·1.5 C₇H₈ 1b，C2/c，a = 38.746(9) Å，b = 10.322(2) Å，c = 27.277(3) Å，β = 110.35(1)°，Z = 8；Re₂(μ - PEt₂)₂Cl₄(PEt₂H)₄ 2a，P2₁/n，a = 11.081(3) Å，b = 11.029(3) Å，c = 15.627(2) Å，β = 90.05(1)°，Z = 2；2b，P2₁/c，a = 16.094(3) Å，b = 15.193(3) Å，c = 15.548(3) Å，β = 100.98(3)°，Z = 4。配合物Re₂Cl₄(PEt₂H)₄ 3的X射线数据如下：P2₁/n，a = 10.445(2) Å，b = 10.113(3) Å，c = 13.473(2) Å，β = 102.17(2)°，Z = 2。面共享配合物1中的三个桥连μ - PEt₂基团跨越的金属 - 金属短距离为2.4060(6) Å（在1a和1b上平均），Re - PEt₂ - Re角小，为61.34(7)°。边共享配合物2中的铼 - 铼键长为2.7545(7) Å（在2a和2b上平均），而桥连Re - PEt₂ - Re角为72.16(6)°，末端膦配体的P - Re - P角为87.11(7)°。3中的Re - Re键距离为2.2533(8) Å，对于三键二铼配合物来说是典型的，顺式膦基团的P - Re - P角为93.12(6)°。
