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.