Owen Summerscales - Unusual electrocyclic rearrangements with group 14 element compounds: reversible formation and isomerization of a pi-aromatic digermyl complex with carbon-carbon and germanium-germanium multiple bond cleavage

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      Publication Details (including relevant citation   information):

      J. Am.   Chem. Soc. 2011  133,   180-183


        Reaction of a digermyne with cyclooctatetraene (cot) gave two   isomeric products. A Ge(II) inverse sandwich is formed as the   kinetic product, which was a result of complete Ge≡Ge bond   cleavage and the formation of a π-bound cot ring. This isomerized   in solution at room temperature over a period of 5 days to give   the thermodynamic product, a tetracyclic diene-digermane, in   which a single-bonded Ge—Ge moiety has inserted into a C═C bond   of the cot carbocycle. Kinetic studies afforded an activation   enthalpy (ΔH)   and entropy (ΔS)   of 14.9 kcal mol−1    and −6.2 cal mol−1    K−1    respectively. Heating crystals of the thermodynamic product at   ca. 120 °C cleanly regenerated the original inverse sandwich   isomer.

      Address (URL): http://dx.doi.org/10.1021%2Fja107380p