34871-13-1Relevant academic research and scientific papers
Oligophosphan-liganden XLII. Carbonyl(cyclopentadienyl) rheniumt(I) -Komplexe η1-C5H5Re(CO)3L2 mit fluktuierender sp3-und starrer sp2-Koordination des C5H5-rings1,2
Dahlenburg, Lutz,Hillmann, Gabriele,Ernst, Markus,Moll, Matthias,Knoch, Falk
, p. 115 - 123 (2007/10/03)
Combination of the halo rhenium(I) complexes fac-Re(CO)3L2X (L/X = PMe3/Br (1), PPh3/Cl (2), PCy3/Br (3)), fac-Re(CO)3(Ph2PCH2PPh2)Br, 4, fac-Re(CO)3[Ph2P(CH2)2PR2]Br (R = Me (5), Ph (6), Cy (7)), fac-Re(CO)3[Ph2P(CH2)3PPh2]Cl, 8, and fac-Re(CO)3[C5H8(PCy2)2]Br, 9 (C5H8(PCy2)2 = rac,trans-cyclopentan-1,2-diyl-bis(dicyclohexyl)phosphine), with Ag[O3SCF3] yielded fac-Re(CO)3(PR3)2OSO2CF3 (R = Me (10), Ph (11), Cy (12)), fac-Re(CO)3[R2P(CH2)nPR2]OSO2CF3 (n-1: R = Ph (13); n = 2: R = Me (14), Ph (15), Cy (16); n = 3: R = Ph (17)), and fac-Re(CO)3[C5H8(PCy2)2]OSO2CF3, 18. Triflates 10, 11, and 14-17 were converted into cyclopentadienyl derivatives containing fluxional sp3-bonded C5H5 rings,fac-η1-C5H5Re(CO)3(PMe3)2, 19, fac-η1-C5H5Re(CO)3[R2P(CH2)nPR2] (n = 2: R = Me (20), Ph (21), Cy (22); n = 3: R = Ph (23)), and mer,trans-η1-C5H5Re(CO)3(PPh3)2, 24, when allowed to interact with Na[C5H5] in THF. Treatment of 18 with Na[C5H5] produced fac-η1-C5H5Re(CO)3[C5H8(PCy2)2] as a mixture of three isomers with the rhenium atom in the allylic position of a fluxional sp3-bonded rings (25a) or in the two vinylic sites of an sp2-bonded rigid C5H5 system, where the CH2 group is either α or β to the metalated carbon atom (25b, 25c). η5-C5H5Re(CO)3 and fac-[Re(CO)3(Ph2PCH2PPh2-P,P′)(Ph2PCH2PPh2-P)]+ were identified as the only organometallic complexes resulting from interaction of triflates 12 and 13 with Na[C5H5]. The structure of fac-η1-C5H5Re(CO)3[Ph2P(CH2)2PPh2] -2CH2Cl2 was determined by single-crystal X-ray diffractometry.
A Re(I)-Re(VII) COMPLEX BY THE OXYGENATION REACTIONS OF Re(I) SPECIES. REACTIVITY AND X-RAY STRUCTURAL CHARACTERIZATION OF Re(CO)3(PPh3)2(OReO3)
Ardizzoia, G. Attilio,Cenini, Sergio,D'Alfonso, Giuseppe,Monica, Girolamo La,Masciocchi, Norberto,Moret, Massimo
, p. 515 - 520 (2007/10/02)
The hydrido complex HRe(CO)2(PPh3)3 reacts with tertiary amines, in the presence of O2 and H2O, to give Re(CO)2(PPh3)2(O2CR), containing a chelating carboxylato group originated by oxidation of the alkyl group of the amine.NEt3, N(n-Pr)3 and N(n-Bu)3 have been used, the acetato, propionato and butyrato derivatives being respectively obtained.In the absence of the amine, the reaction gives the Re(I)-Re(VII) complex Re(CO)3(PPh3)2(OReO3), 1, containing a coordinated perrhenate ion.The same species was obtained by reaction of Re(CO)2(PPh3)2(NHCOC6H4Me) with O2/H2O.Complex 1 has been alternatively prepared by reacting ReCl(CO)3(PPh3)2 with AgReO4.Crystals of 1 have been shown by single crystal X-ray analysis to be monoclinic, space group P21/n (No. 14) with a = 10.248(6), b = 27.487(5), c = 13.247(2) Angstroem, β = 97.55(2) deg and Z = 4.The refinement performed by full-matrix least-squares methods, for 4651 independent significant reflections, gave a final R value of 0.029.The crystals contain discrete dinuclear molecules with an octahedrally coordinated Re(I) atom bearing three carbonyls, two mutually trans triphenylphosphine ligands and a coordinated ReO4- moiety.Complex 1 was shown to be partially dissociated in acetone solution and the value of the dissociation constant has been estimated by means of the Ostwald relationship -5>.The addition of NEt3 to an acetone solution of 1 at room temperature causes its complete dissociation.Complete dissociation was also observed in acetonitrile, with formation of the ionic species , 2.Complex 1 reacts with NEt3, at 55 deg C under an inert atmosphere, to give the rhenium(I) acetato derivative Re(CO)2(PPh3)2(O2CCH3), showing that the perrhenate anion is able to perform the oxidation of alkyl groups of tertiary amines to carboxylato groups.
