Abstract
The heats of formation ( ΔH f 298) for ketene (1, −52 kJ mol −1), methylketene (2, −68 kJ mol −1), dimethylketene (3, −92 kJ mol −1), and their radical cations 1 + (875 kJ mol −1), 2 + (797 kJ mol −1) and 3 + (726 kJ mol −1) have been determined at high levels of theory including variants of the G2 and CBS procedures. Agreement with experiment is good for the ionization energies of 1, 2 and 3 and for the heats of formations of 1 and 1 + but not for the heats of formation of 2, 3, 2 + and 3 +. This disagreement is puzzling and suggests that a re-examination of the experimental estimates would be desirable. The effect of a single methyl substituent on the heat of formation is predicted to be considerably lower for ketene (our best estimate being −16 kJ mol −1) than for ethylene (−31 kJ mol −1), allene (−27 kJ mol −1) or formaldehyde (−54 kJ mol −1).
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
More From: International Journal of Mass Spectrometry and Ion Processes
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.