The Anions [Cp^tt₂Zr(μ-S)₂M(CO)₂]^- (M = Rh, Ir) as Versatile Precursors for the Synthesis of Sulfido-Bridged Early−Late Heterotrimetallic (ELHT) Compounds^†

The reaction of [Cp^tt₂Zr(μ₃-S)₂{Ir(CO)₂}₂] (Cp^tt = η⁵-1,3-di-tert-butylcyclopentadienyl) with dppe (1,2-bis-(diphenylphosphino)ethane) affords the ion-pair compound [Ir(CO)(dppe)₂][Cp^tt₂Zr(μ-S)₂Ir(CO)₂] (2). The related compound [Rh(dppe)₂][Cp^tt₂Zr(μ-S)₂Rh(CO)₂] (5) has been obtained in solution under a carbon monoxide atmosphere by reaction of [Cp^tt₂Zr(μ₃-S)₂{Rh(CO)₂}₂] with dppe through the intermediate heterotrinuclear compound [Cp^tt₂Zr(μ₃-S)₂{Rh(dppe)}{Rh(CO)₂}] (4). Reaction of the heterodinuclear anion [Cp^tt₂Zr(μ-S)₂Ir(CO)₂]^-, generated in situ, with [Rh(μ-Cl)(cod)]₂, [RhCl₂(CO)₂]^- and [Pd(μ-Cl)(η³-C₃H₅)]₂ affords the d⁰−d⁸−d⁸ early−late compounds [Cp^tt₂Zr(μ₃-S)₂{Ir(CO)₂}{Rh(cod)}] (6), [Cp^tt₂Zr(μ₃-S)₂{Ir(CO)₂}{Rh(CO)₂}] (7), and [Cp^tt₂Zr(μ₃-S)₂{Ir(CO)₂}{Pd(η³-C₃H₅)}] (8) each with a symmetrical trigonal−bipyramidal M₃(μ₃-S)₂ heterotrimetallic metal−sulfur core. In the same way, the reaction of [Cp^tt₂Zr(μ-S)₂M(CO)₂]^- (M = Rh, Ir) with [AuCl(PPh₃)] leads to the preparation of the d⁰−d⁸−d¹⁰ early−late compounds [Cp^tt₂Zr(μ-S)₂{Ir(CO)₂}{Au(PPh₃)}] (9) and [Cp^tt₂Zr(μ-S)₂{Rh(CO)₂}{Au(PPh₃)}] (10) with an open M₃(μ₃-S)(μ₂-S) heterotrimetallic metal−sulfur framework. On the other hand, treatment of the bis(hydrosulfido)zirconium compound [Cp^tt₂Zr(SH)₂] with triethylamine followed by addition of [Pd(μ-Cl)(η³-C₃H₅)]₂ or [AuCl(PPh₃)] affords the sulfido-bridged early−late heterobimetallic compounds [Cp^tt₂Zr(μ₃-S)₂{Pd(η³-C₃H₅)}₂] (11) and [Cp^tt₂Zr(μ-S)₂{Au(PPh₃)}₂] (12). The molecular structure of complexes 9 and 12 determined by X-ray diffraction methods are also described.