- Reactions of the polyhydrides Re2H8(PPh3)4 and ReH7(PPh3)2 with acetic acid/acetic anhydride. Isolation and characterization of the rhenium(I) carbonyl complexes Re(O2CCH3)(CO)1+x(PPh3) 3-x (x = 0, 1) and the homoleptic dirhenium(III) ...
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Full title: Reactions of the polyhydrides Re2H8(PPh3)4 and ReH7(PPh3)2 with acetic acid/acetic anhydride. Isolation and characterization of the rhenium(I) carbonyl complexes Re(O2CCH3)(CO)1+x(PPh3) 3-x (x = 0, 1) and the homoleptic dirhenium(III) carboxylate complex Re2(μ-O2CCH3)4(O 2CCH3)2. The dirhenium octahydride Re2H8(PPh3)4 reacts with acetic acid/acetic anhydride mixtures in dichlorobenzene to give the homoleptic acetate complex Re2(μ-O2CCH3)4(O 2CCH3)2 as the major product together with small quantities of the carbonyl complex Re(O2CCH3)(CO)2(PPh3)2. The related reaction with propionic acid/propionic anhydride gives only Re(O2CC2H5)-(CO)2(PPh 3)2 in very low yield. Treatment of ReH7(PPh3)2 with these same acid/anhydride mixtures in THF, in the presence of PPh3, affords yellow Re(O2CR)(CO)(PPh3)3 (R = CH3, C2H5) in high yield. Solutions of these complexes in 0.1 M n-Bu4NPF6/CH2Cl2 show a reversible couple in their cyclic voltammograms associated with a one-electron oxidation to their 17-electron cations. Chemical oxidation of Re(O2CR)(CO)(PPh3)3 to the paramagnetic, orange salts [Re(O2CR)(CO)(PPh3)3]PF6 has been accomplished by using [(η5-C5H5)2Fe]PF6 in acetone. The acetate complex [Re(O2CCH3)(CO)(PPh3)3]PF 6·THF has been characterized structurally by X-ray crystallography. Crystal data at 20°C: space group Pnma, a = 15.785 (4) A?, b = 22.577 (3) A?, c = 23.824 (3) A?, V = 5656 (5) A?3, and Z = 4. The structure was refined to R = 0.033 and Rw = 0.040 for 2600 data with F2 > 3.0σ(F2).
- Cameron, Charles J.,Fanwick, Phillip E.,Leeaphon, Malee,Walton, Richard A.
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p. 1101 - 1104
(2008/10/08)
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