T. To, C. Duke, Christopher S. Junker
Jan 3, 2008
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Influential Citations
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Journal
Organometallics
Abstract
Two, bifunctional side-chain cyclopentadienylmanganese tricarbonyl complexes, 7 (pyridine and ketone side chain) and 14 (thioamide and pyridine side chain), were prepared and converted to chelates following CO dissociation by UV irradiation. Both pyridine (8) and carbonyl (9) chelates are observed following irradiation of 7. In contrast, only thioamide chelate (16) is observed following irradiation of 14 even though a pyridine group was available. Visible irradiation isomerizes the pyridine chelate 8 to the carbonyl chelate 9, which thermally isomerizes back to 8 at 25 °C in a few minutes, demonstrating a photochromic response from a cyclopentadienyl-manganese complex based on a linkage isomerization of a tethered functional group. DFT calculations predicted that the activation enthalpy of thermal linkage isomerization would be 20.8 kcal/mol and that the mechanism is likely an associative process that does not involve a simple dissociation of the manganese bond to the side-chain ketone. The DFT calculatio...