65531-96-6Relevant academic research and scientific papers
Oxidation and substitution kinetics of Re2(CO)8{P(C6H11)3} 2
Po?, Anthony J.,Sampson, Clifford N.,Sekhar, Chandra V.
, p. 1057 - 1060 (2008/10/08)
The kinetics of reactions of ax,ax-Re2(CO)8(PCy3)2 (Cy = C6H11) with C16H33I, P(OPh)3, and P(OEt)3 in decalin have been studied. Reaction with C16H33I leads to cis-Re(CO)4(PCy3)I by three paths. The major one accounts for ca. 93% of the total reaction rate, and the data are consistent with rate-determining dissociation of PCy3. Rate-determining CO dissociation can account for another 5%, but there seems to be an additional, but very minor, path accounting for ca. 2% of the reaction. The values of ΔH? and ΔS? corresponding to PCy3 dissociation are close to 30 kcal mol-1 and -3 cal K-1 mol-1, respectively. It is suggested that, as the PCy3 ligand leaves, the remaining Re2(CO)8(PCy3) moiety adjusts its bonding so as to maintain 18-electron configurations for both Re atoms and that this accounts for the low values of both activation parameters. In spite of the bulk of the PCy3 substituents, a rather high lower limit, ΔH? ≥ 41 kcal mol-1, is estimated for homolysis of the Re-Re bond.
THE REACTIONS OF DECACARBONYLDIRHENIUM WITH SOME ORGANO-PHOSPHANES AND PHOSPHITES
Cox, David J.,Davis, Reg
, p. 347 - 352 (2007/10/02)
The reactions between Re2(CO)10 and a number of organo-phosphanes and phosphites in refluxing xylene have been studied.With P(OPh)3, the products are 1,2-diaxial-Re2(CO)8L2 and 1-axial-2,2'-axial,equatorial-Re2(CO)7L3, whereas with (o-CH3C6H4O)3P, 1,2-diaxial-Re2(CO)8L2 and the metalated complex Re(CO)3L(L-H) are formed.In the case of (p-ClC6H4O)3P, only 1,2-diaxial-Re2(CO)8L2 was isolated. (p-CH3C6H4)3P and (cyclohexyl)3P both yield 1,2-diaxial-Re2(CO)8L2 and mer-trans-HRe(CO)3L2, however, (o-CH3C6H4)3P gives only the metalated product, Re(CO)4L-H.Formation of the hydrides and metalated compounds is rationalised in terms of the homolysis of the metal-metal bonded dimers to yield metal-centred free radical intermediates.The behaviour of the dimers and the radical intermediates is discussed in terms of the properties of the phosphorus donor ligands.
