27770-64-5Relevant academic research and scientific papers
Substituted metal carbonyls. 26.1 One-step synthesis, structures, NMR, and dynamic laser-light scattering of Re2(μ-OMe)2[μ-Ph2P(CH2) nPPh2](CO)6 (n = 1-4)
Low, Pauline M. N.,Yong, Yuk Lin,Yan, Yaw Kai,Hor, T. S. Andy,Lam, Sik-Lok,Chan, Kam Kwong,Wu, Chi,Au-Yeung, Steve C. F.,Wen, Yuh-Sheng,Liu, Ling-Kang
, p. 1369 - 1374 (2008/10/08)
Oxidative decarbonylation of Re2(CO)10 by Me3NO in a mixture of THF and MeOH followed by addition of alkyl-chained diphosphine Ph2P(CH2)nPPh2 (PP) (n = 1-4) gives Re2(μ-OMe)2-(μ-PP)(CO)6 in 34, 29, 28, and 10% yields, respectively. This methanolytic oxidation across the Re-Re bond provides a general and one-step route for the synthesis of these dirhenium hexacarbonyl complexes with diphosphine and methoxo bridges. The molecular structure of Re2(μ-OMe)2(μ-Ph2PCH2PPh 2)(CO)6 was determined by single-crystal X-ray diffraction analysis. It contains two fac-[Re(CO)3] moieties bridged by dppm and two methoxo ligands. The {Re2O2} core is significantly more planar than that in the Fe(C5H4PPh2)2 analogue. That such a dinuclear core is maintained in spite of the different steric demands of the different bridging diphosphines illustrates the great geometric tolerance of the bridging methoxo groups. The fluxionality of the dppm, dppe, and dppp complexes has been studied and compared by molecular modeling and solution 1H NMR spectroscopy. Dynamic laser-light scattering (DLS) shows that the dppe complex aggregates in CH2Cl2 to form small clusters with an average radius of ～370 nm. The use of a combination of DLS and NMR in organometallic chemistry is unprecedented.
Photophysical Studies of XRe(CO)4L (X = Cl, I; L = CO, pip, PPh3) Complexes. Examples of Ligand Field Luminescence from Organometallic Complexes on Fluid Solution
Glezen, Marsha M.,Lees, Alistair J.
, p. 3892 - 3897 (2007/10/02)
A series of cis-XRe(CO)4L complexes have been prepared via photochemical and thermal reactions of the parent XRe(CO)5 species.Electronic absorption spectra have been recorded for these complexes in solution at 293 K and in EPA glasses at 80 K.The lowest lying absorption system is assigned definitively to ligand field (LF)1A1(e4b22) 1,3E(e3b22a11) transitions; the band energies depend on L and are ordered CO > P donor > N donor, in accordance with the LF strength.Luminescence spectra, lifetimes, quantum yields, and excitation spectra from the cis-XRe(CO)4L (L = pip, PPh3) derivatives in both 293 K solution and EPA glasses at 80 K are consistent with emission from the lowest energy 3LF state.In contrast, the parent XRe(CO)5 molecules were not found to emit under identical experimental conditions.The photochemistry of these cis-XRe(CO)4L complexes has also been investigated.Irradiations at 313 or 366 nm of cis-XRe(CO)4L in solution at 293 K that contains an excess concentration of entering ligand give rise to ligand-substitution processes involving replacement of both CO and PPh3 ligands.Irradiations at 313 nm of cis-IRe(CO)4(PPh3) in solution at 293 K without added scavenging ligands leads to formation of carbonyl-bridged 2 dimer and I2 products.These photochemical processes are correlated with the model of lowest lying electronically excited states.
FREE RADICAL INTERMEDIATES IN THE REACTION BETWEEN DECACARBONYLDIRHENIUM AND TRIPHENYLPHOSPHANE
Cox, David J.,Davis, Reg
, p. 339 - 345 (2007/10/02)
The reaction between Re2(CO)10 and PPh3 in refluxing xylene has been re-examined.The main products are 1,2-diaxial Re2(CO)8(PPh3)2 and mer-trans-HRe(CO)(PPh3)2.A range of other products have been isolated by chromatographic procedures and their production rationalised.The previously reported isolable paramagnetic products have not been confirmed, but evidence is presented for their formation as unstable intermediates.
