Rhenium aryloxides

Recent mechanistic work on the formation of rhenium aryloxides by treatment of the corresponding methoxide, ethoxide, or isopropoxide with phenolic reagents, shows the intermediacy of a hydrogen-bonded adduct as well as the exchange pathway shown in Eq. 6.45. 29... 

The chemistry of rhenium aryloxides is significant. The homoleptic rhenium aryloxides [Re(OAr)4] (OAr = OC6H3Pr -2,6, OC6H3Me2-2,6) have been obtained from [ReCl4(THF)2] and Ihe corresponding lithium aryloxide." " Cyclic voltammetric studies show these square planar d -species can undergo one-electron reduction. As with other transition metal systems (Section 4.2.3) these aryloxides are more difficult to reduce (more negative potential) than their halide counterparts. The 2,6-dimethylphenoxide compound reacts with alkynes to form adducts [(RCCR)Re(OAr)4]. 

In addition to the well-established chemistry of the M—O bond in M—O—C derivatives (4, 6, 7, 14, 28-32, 38, 39), the chemical reactivity of the C —O bond in aryloxide and related derivatives of mainly rhenium and tungsten (43) was recently highlighted by Mayer (164). Although the main focus of this con-... 

Edwards D.A., Mahon M.F., Molloy K.C., Ogrodnik V. Silver(I) aryloxide-triphenylphosphine complexes. An assessment of their potential as CVD precursors and the structure of [Ag(OC6H4Me-2)(PPh3)3]-2-MeC6H40H.C6H5Me. Inorg. Chim. Acta 2003, 349 37 Edwards P.G., Jokela J., Lehtonen A., Sillanpaa R. Preparation and reactions of rhenium(VII) trioxo hydrogendiolato complexes and rhenium(VI) oxo bis(diolato) complexes. J. Chem. Soc., Dalton Trans. 1998 3287... 

R.D. Simpson, R.G. Bergman - Synthesis, Structure, and Exchange-Reactions of Rhenium Alkoxide and Aryloxide Complexes. Evidence for Both Proton and H-Atom Transfer in the Exchange Transition State, Organometallics 12,781,1993. 

---