Use of the monocationic fragment [Ru(î|5-C5H5)(MeCN)3]+ as an ionic coupling reagent in the synthesis of mixed-metal phosphine clustersf

Deprotonation of [Os3H ₂(CO)IO(PPh3)], with DBU (l, 8-diazabicyclo[5.4.0]undec-7-ene), and subsequent treatment with the ionic coupling reagent [Ru(n5-C5Hj)(MeCN)3][PF6] afforded the tetrahedral cluster [Os3H(CO)10(PPh3){Ru(ns-C5Hj)}J. Reduction of the trinuclear osmium cluster [Os3(CO), , (PPh3)] with K/Ph2CO and subsequent coupling with [Ru(n5-C5H5)(MeCN)3][PF6] yielded the pentanuclear clusters [Os-4CCOntPPhjMRuOi'-CjHjWj], [OsjHjCCO-4.tPPhjKRutn'-CjHj)-4] and the butterfly cluster [Os3H(CO)u(PPh3){Ru(ii5-C5H5)}J. In an analogous reaction using [Osj(CO)n{P(OMe)3}] only one complex [Os3(CO), , {P(OMe)3} {Ru(ti5-CsHj)}2] was isolated. This undergoes an orthometallation when heated under reflux in toluene to yield the novel spiked tetrahedral cluster [Os3Ru2H(CO)n{P(OMe)3}(n5-CjHj)(nj-Ti5-C5H4)J. All the new complexes have been characterised spectroscopically and the molecular and crystal structures of three have been determined by single-crystal X-ray diffraction. The structure of [Os3Ru2H(CO), , {P(OMe)3}(r|5-C5Hj)(u3-7i5-C3H4)] shows an uncommon u3-T|5-bonding mode for the deprotonated cyclopentadiene ring.