Journal article

Publication year: 2020

Pages: 19457-19461

Journal: Journal of the American Chemical Society

Volume number: 142

Issue number: 46

DOI Link: https://doi.org/10.1021/jacs.0c09317

Publisher: American Chemical Society

Abstract: 

We report the first preparation of the s-cis,s-cis conformer of dihydroxycarbene (1cc) by means of pyrolysis of oxalic acid, isolation of the lower-energy s-trans,s-trans (1tt) and s-cis,s-trans (1ct) product conformers at cryogenic temperatures in a N₂ matrix, and subsequent narrow-band near-infrared (NIR) laser excitation to give 1cc. Carbene 1cc converts quickly to 1ct via quantum-mechanical tunneling with an effective half-life of 22 min at 3 K. The potential energy surface features around 1 were pinpointed by convergent focal point analysis targeting the AE-CCSDT(Q)/CBS level of electronic structure theory. Computations of the tunneling kinetics confirm the time scale of the 1cc → 1ct rotamerization and suggest that direct 1cc → H₂ + CO₂ decomposition may also be a minor pathway. The intriguing latter possibility cannot be confirmed spectroscopically, but hints of it may be present in the measured kinetic profiles.

Harvard Citation style: Quanz, H., Bernhardt, B., Erb, F., Bartlett, M., Allen, W. and Schreiner, P. (2020) Identification and Reactivity of s-cis,s-cis-Dihydroxycarbene, a New [CH2O2] Intermediate, Journal of the American Chemical Society, 142(46), pp. 19457-19461. https://doi.org/10.1021/jacs.0c09317

APA Citation style: Quanz, H., Bernhardt, B., Erb, F., Bartlett, M., Allen, W., & Schreiner, P. (2020). Identification and Reactivity of s-cis,s-cis-Dihydroxycarbene, a New [CH2O2] Intermediate. Journal of the American Chemical Society. 142(46), 19457-19461. https://doi.org/10.1021/jacs.0c09317