The kinetics for the isomerization of the 50e cluster Os3(μ-TeTol-p)2(CO)10 (3), where the tellurides bridge two different Os–Os edges, to one in which the tellurides bridge the same open Os⋯Os edge (4) have been measured experimentally by 1H NMR spectroscopy. The determined activation parameters are ΔH‡ = 77 ± 9 kJ mol−1 and ΔS‡ = −12 ± 28 J mol−1 K. The conversion of 3 to 4 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.
