Improved syntheses of [image] and [image]: Structural characterization of Na[Cp∗MoO3] · 5H2O and [image]

Use of aqueous conditions and the ROOH (R = t Bu or H) compounds as oxidizing agents affords a simple two-step, one-pot synthetic procedure leading to [View the MathML sourceCp2∗M2O5] (M = Mo, W) from [M(CO)6] selectively and in high yields. The hexacarbonyl compounds are converted to Na[Cp∗M(CO)3] in refluxing THF, then the mixture is diluted with water (W) or aqueous NaOH (Mo) and directly treated with 6 equiv. of ROOH. Acidification of an aqueous solution of the Na[Cp∗MO3] product affords spectroscopically pure [View the MathML sourceCp2∗M2O5] in high isolated yields (global yields from [M(CO)6], for R = t Bu: Mo, 91%; W, 87%). The X-ray structures of Na[Cp∗MoO3] · 5H2O and [View the MathML sourceCp2∗W2O5] are also reported.