71946-83-3Relevant articles and documents
Identification and Reactivity of s- cis, s- cis-Dihydroxycarbene, a New [CH2O2] Intermediate
Quanz, Henrik,Bernhardt, Bastian,Erb, Frederik R.,Bartlett, Marcus A.,Allen, Wesley D.,Schreiner, Peter R.
, p. 19457 - 19461 (2020/12/18)
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.
Spectroscopic identification of dihydroxycarbene
Schreiner, Peter R.,Reisenauer, Hans Peter
supporting information; experimental part, p. 7071 - 7074 (2009/04/07)
Out and about: CO2 extrusion from simple α-keto carboxylic acids can be used to prepare hitherto unknown hydroxycarbenes. High-vacuum flash pyrolysis of oxalic acid or its monomethyl ester enabled the preparation and characterization of dihydro
