84538-00-1Relevant articles and documents
Crystal and molecular structure and substitution reactivity of (μ-hydrido)(μ-pyridyl)dirhenium octacarbonyl, (μ-H)Re2(CO)8(μ-NC5H4). Crystal and molecular structure of (μ-hydrido)(μ-pyridyl) (trimethylamine N-oxide)dirhenium heptacarbonyl, (μ-H)Re2(CO)7(μ-NC5H4)(Me 3NO)
Nubel, Philip O.,Wilson, Scott R.,Brown, Theodore L.
, p. 515 - 525 (2008/10/08)
An X-ray crystal structure determination of (μ-H)Re2(CO)8(μ-NC5H4), I, has been performed. The compound crystallizes in the triclinic space group P1, with a = 13.864 (5) A?, b = 14.927 (5) A?, c = 8.855 (2) A?, α = 99.00 (3)°, β = 92.68 (3)°, γ = 65.66 (2)°, V = 1648.8 (9) A?3, and Z = 4. Two independent but structurally similar molecules were observed per asymmetric unit of the unit cell. The hydride of each was located in a bridging position opposite the μ-pyridyl ligand. The Re-Re distances, 3.2088 (4) and 3.1956 (5) A?, are consistent with a H-bridged Re-Re single bond. This compound reacts with Me3NO to yield (μ-H)Re2(CO)7(μ-NC5H 4)(NMe3), which undergoes reaction with excess Me3NO to produce (μ-H)Re2-(CO)7(μ-NC5H 4)(Me3NO), III. The structure of III has been determined by X-ray crystallography. III crystallizes in the orthorhombic space group Pbca, with a = 14.662 (4) A?, b = 26.300 (6) A?, c = 10.201 (2) A?, V = 3934 (2) A?3, and Z = 8. The amine oxide ligand of III is coordinated to the same Re as the μ-pyridyl nitrogen. CO substitution of I by other ligands has been attained via three methods: (1) reaction with Me3NO in the presence of excess L (pyridine, PPh3), (2) thermal reaction with L (refluxing benzene; L = pyridine, PPh3, CH3CN), or (3) 366-nm photolysis (L = pyridine, PPh3, P(OPh)3, 1-octene). The μ-hydrido, μ-pyridyl structure is maintained in the products. Monosubstituted products are proposed to be isostructural with III on the basis of IR data. Disubstitution has been achieved by all three methods for L = pyridine and PPh3. Isomeric disubstituted products were observed; structures are proposed for some of these based upon IR data. Trisubstituted products (L = pyridine, PPh3) have been obtained only through photolysis.
