Bimetallic osmium-tin complexes: Stannylene and hydrostannylene clusters upon addition of Ph3SnH to unsaturated triosmium clusters [(μ-H)2Os3(CO)8(μ-diphosphine)] (diphosphine=dppm, dppf)

Reactions of diphosphine-stabilized Os3 clusters with triphenylantimony: syntheses and structures of new antimony-containing Os3 clusters via Sb-Ph bond cleavage

The reactivity of the trimetallic clusters [Os₃(CO)₁₀(μ-dppm)] [dppm = bis(diphenylphosphino)methane] and [HOs₃(CO)₈{μ₃-Ph₂PCH₂PPh(C₆H₄-μ₂,σ¹)}] with triphenylantimony (SbPh₃) has been examined. [Os₃(CO)₁₀(μ-dppm)] reacts with SbPh₃ in refluxing toluene to yield three new triosmium clusters [Os₃(CO)₉(SbPh₃)(μ-dppm)] (1), [HOs₃(CO)₇(SbPh₃){μ₃-Ph₂PCH₂PPh(C₆H₄-μ₂,σ¹)}] (2), and [HOs₃(CO)₇(SbPh₃)(μ-C₆H₄)(μ-SbPh₂)(μ-dppm)] (3). [HOs₃(CO)₈{μ₃-Ph₂PCH₂PPh(C₆H₄-μ₂,σ¹)}] reacts with SbPh₃ (excess) at room temperature to afford [Os₃(CO)₈(SbPh₃)(η¹-Ph)(μ-SbPh₂)(μ-dppm)] (4) as the sole product. A series of control experiments have also been conducted to establish the relationship between the different products. The molecular structure of each product has been determined by single-crystal X-ray diffraction analysis, and the bonding in these new clusters has been investigated by electronic structure calculations.

Isomerization of the osmium-tellurium cluster Os3(μ-TeR)2(CO)10: a kinetic and computational study

The kinetics for the isomerization of the 50e cluster Os3(μ-TeTol-p)2(CO)10 (), where the tellurides bridge two different Os-Os edges, to one in which the tellurides bridge the same open OsOs edge () have been measured experimentally by (1)H NMR spectroscopy. The determined activation parameters are ΔH(‡) = 77 ± 9 kJ mol(-1) and ΔS(‡) = -12 ± 28 J mol(-1) K. The conversion of to has been computationally investigated by electronic structure calculations using the model compound Os3(μ-TeMe)2(CO)10. The computed isomerization pathway is consistent with the kinetic data and the thermodynamic preference for the product stereoisomer that possesses a slipped, eclipsed conformation for the two p-tolyl groups.