Chemistry of polynuclear metal complexes with bridging carbene or carbyne ligands. Part 72. Di- and tri-metal compounds prepared from the alkylidyne tungsten complexes [W(CR)(CO)3{H2B(pz)2}][R = C6H4Me-4 or Me, H2B(pz)2= dihydrobis(pyrazol-1-yl)borate]

Abstract

The alkylidynetungsten compounds [W(CR)(CO)₃{H₂B(pz)₂}][R = C₆H₄Me-4 or Me, H₂B(pz)₂= dihydrobis(pyrazol-1-yl)borate] have been prepared, and used to prepare several complexes containing bonds between tungsten and other transition elements. Thus the compounds [Co₂W(µ₃-CC₆H₄Me-4)(CO)₉{H₂B(pz)₂}], [Rh₂W(µ₃-CMe)(µ-CO)(CO)₃(η⁵-C₉H₇)₂{H₂B(pz)₂}](η⁵-C₉H₇= indenyl), [FeW(µ-CC₆H₄Me-4)(CO)₆{H₂B(pz)₂}], [PtW(µ-CC₆H₄Me-4)(CO)₃(cod){H₂B(pz)₂}](cod = cyclo-octa-1,5-diene), and [MW₂(µ-CR)₂(CO)₆{H₂B(pz)₂}₂](M = Ni or Pt, R = C₆H₄Me-4; M = Pt, R = Me) have been synthesised by treating the appropriate alkylidynetungsten compound with [Co₂(CO)₈], [Rh(CO)₂(η⁵-C₉H₇)], [Fe₂(CO)₉], or [M(cod)₂](M = Ni or Pt), respectively. The unsaturated dimetal compound [FeW(µ-CC₆H₄Me-4)(CO)₆{H₂B(pz)₂}] reacts with dppm (Ph₂PCH₂PPh₂), RCCR (R = Me or Ph), and CH₂N₂ to afford the complexes [FeW(µ-CC₆H₄Me-4)(µ-CO)(µ-dppm)(CO)₃{H₂B(pz)₂}], [FeW{µ-C(C₆H₄Me-4)C(R)C(R)}(CO)₆{H₂B(pz)₂}], and [FeW{µ-trans-CHC(H)C₆H₄Me-4}(µ-CO)(CO)₆{H₂B(pz)₂}], respectively. N.m.r. data (¹H, ¹³C-{¹H}, ³¹P-{¹H}, or ¹⁹⁵Pt-{¹H}) for the new compounds are reported and discussed in relation to the structures proposed.