Matrix IR spectra and quantum chemical studies of the reaction between difluorostannylene and hept-1-yne. The first direct observation of a carbene analog π-complex with alkne
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IR studies of SnF2 and hept-1-yne codeposited in an argon matrix at 12 K has revealed new bands at 540, 565, 1011, 2088 and 3256 cm−1, assigned to the formation of a complex between SnF2 and the alkyne. Quantum chemical AM1 and PM3 calculations confirm this assignment to the π-complex of SnF2 and the triple bond of hept-1-yne, and show that the complex forms without an activation barrier. The energy of the formation of the complex according to AM1 and PM3 calculations is 7.4 and 9.1 kcal/mol, respectively. The calculations indicate that the product of the cycloaddition of SnF2 to a triple bond, stannyrene, is significantly less stable than the π-complex.
Key wordsπ-complex difluorostannylene hept-1-yne matrix IR spectra AM1 PM3
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