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• 14023-10-0 tetra-n-butylammonium octachlorodirhenate(III) 
• 1663-45-2 1,2-bis-(diphenylphosphino)ethane 

Relevant academic research and scientific papers

Isomerization in Metal-Metal Bonded M2L10 Systems Involving Cis and Trans Sets of Bis(diphenylphosphino)methane Ligands

The reactions of the dirhenium(III) complexes Re2(O2CR)4X2 (R = CH3, C2H5, C6H5; X = Cl, Br), Re2(O2CR)2X4L2 (R = CH3, C2H5; X = Cl, Br; L = H2O, 4-methylpyridine, DMF, DMSO), and (n-Bu4N)2Re2X8 (X = Cl, Br) with Ph2PCH2PPh2 (abbreviated dppm) or, in the case of (n-Bu4N)2Re2X8, Ph2CH2PPh2/acetate mixtures affords the reduced complexes Re2(O2CR)X4(dppm)2 and cis- and trans-Re2(O2CR)2X2(dppm)2 depending upon the choice of reaction conditions.The thermolysis of Re2(O2CR)X4(dppm)2 provides a high yield synthetic route to Re2X4(dppm)2 (X = Cl, Br), a procedure that can be adapted to produce Re2I4(dppm)2 directly from Re2(O2CCH3)2I4.nH2O.The cis and trans isomers of the triply bonded dirhenium(II) compounds Re2(O2CR)2X2(dppm)2 can be oxidized to paramagnetic cis-PF6 and trans-PF6 by 5-C5H5)2Fe>PF6 and (C7H7)PF6, respectively.The structures of representative members of these groups of new complexes have been established by X-ray crystallography, viz., Re2(O2CCH3)Cl4(dppm)2.2(CH3)2CO (1), cis-Re2(O2CCH3)2Cl2(dppm)2 (2), and trans-PF6.CH2Cl2 (3).Complex 1 crystallizes in the monoclinic space group P21/c with the following unit cell dimensions: a = 12.720 (2) Angstroem, b = 35.593 (5) Angstroem, c = 9.405 (2) Angstroem, β = 104.36 (1) deg, V = 5610 (3) Angstroem3, and Z = 4.The structure was refined to R = 0.036 and Rw = 0.055 for 5822 data with F2 > 3.0?(F2).The structure contains symmetrically bridging acetate and dppm ligands and is based upon an eclipsed M2L10 geometry, with two axial and two equatorial Re-Cl bonds.The Re-Re distance is 2.300 (1) Angstroem, which is in accord with the presence of a Re-Re bond of order 3.5.The unit cell dimensions for complexes 2 and 3, which crystallize in the monoclinic space groups P21/c and C2/c, respectively, are as follows: for 2, a = 14.634 (6) Angstroem, b = 15.190 (5) Angstroem, c = 24.281 (6) Angstroem, β = 107.24 (3) deg, V = 5155 (6) Angstroem3, and Z = 4; for 3, a = 22.853 (5) Angstroem, b = 18.712 (3) Angstroem, c = 14.236 (4) Angstroem, β = 107.48 (2) deg, V = 5807 (4) Angstroem3, and Z = 4.The structure of 2 was refined to R = 0.045 and Rw = 0.061 for 4468 data with F2 > 3.0?(F2), whereas for 3 the refinement gave R = 0.034 and Rw = 0.049 for 2936 data with F2 > 3.0?(F2).Both complexes contain pairs of bridging acetate and dppm ligands and axial Re-Cl bonds.In 2 the pairs of acetate (and dppm) ligands are cis to one another, while they assume a trans disposition in 3.The Re-Re distance is 2.315 (1) Angstroem in 2 and 2.275 (1) Angstroem in 3.

Studies on the α and β isomers of complexes of the type Re2X4(LL)2. Structural characterization of α- and β-Re2Cl4(dppee)2 (dppee = cis-Ph2PCH=CHPPh2)

The first structural study on a pair of α and β isomers of dirhenium(II) of the type Re2X4(LL)2 (X = Cl, Br; LL = bidentate phosphine ligand) has been carried out in the case of X = Cl and LL = cis-Ph2PCH=CHPPh2 (dppee). Crystals of α-Re2Cl4(dppee)2·n-PrOH, which were grown from CH2Cl2/n-propyl alcohol, crystallize in the triclinic space group P1 with the following unit cell dimensions: a = 13.485 (3) A?, b = 17.556 (5) A?, c = 11.952 (3) A?, a = 87.24 (2)°, β = 100.12 (2)°, γ = 110.66 (2)°, V = 2606 (3) A? 3, and Z = 4. The structure was refined to R = 0.037 (Rw = 0.048), with quality of fit 1.403, for 5384 data with Fo2 > 3σ(Fo2). There are two crystallographically independent molecules, which are essentially identical structurally with an average Re≡Re distance of 2.258 A?. The centrosymmetric molecules contain chelating dppee ligands and possess an eclipsed rotational geometry. The isomer β-Re2Cl4(dppee)2 crystallizes in the monoclinic system, space group P21/n, with a = 16.917 (2) A?, b = 12.992 (4) A?, c = 22.990 (7) A?, β = 106.86 (2)°, V = 4836 (4) A?3, and Z = 4. The structure was refined to residuals of R = 0.088 and Rw = 0.074 and quality of fit 2.389 for 3002 data with Fo2 > 3σ(Fo2). Refinement of the structure was complicated by a disorder in which a second set of rhenium atoms (20% occupancy) was found, centered at the same point as the principal pair (80% occupancy), and with the Re-Re vector roughly perpendicular to that of the primary Re2 unit. The Re≡Re distance was refined to 2.242 (3) A? for the major component of the disorder. The molecules possess an overall staggered geometry in which the dppee ligands bridge the two metal centers. The resulting six-membered ring conformations in both the principal and minor molecules are of the type well-known for cyclohexene, namely, a flattened chair or half-chair. Synthetic procedures have been developed for the preparation of α-Re2X4(dppe)2 (X = Cl, Br; dppe = Ph2PCH2CH2PPh2), complexes whose β isomers have been reported previously. The first successful chemical oxidation of α isomers of dirhenium(II) has been accomplished; α-Re2Cl4(LL)2 complexes (LL = cis-Ph2PCH=CHPPh2, Ph2P(CH2)3PPh2) have been oxidized by (Cp2Fe)PF6 in CH2Cl2 to give paramagnetic α-[Re2Cl4(LL)2]PF6.