Archive for June, 2026
Evaluating metadata quality and completeness for research data using the new DataCite Tool.
Wednesday, June 17th, 2026
A 1965 precedent to the Dewar Pyrimidone MOST system – and text book examples of the Woodward-Hoffmann pericyclic reaction selection rules
Monday, June 1st, 2026In the previous post,[1] I noted the photochemical isomerisation of a pyrimidone into what is called the bicyclic Dewar form, being part of a solar energy storage system.[2] A colleague (thanks Alan!) has recollected a very similar example dating from 1965[3] in which a related molecule known as a diazepinone 72 (scheme below) is converted by light into a Dewar form 73.
References
- H. Rzepa, "A breakthrough in Molecular Solar Thermal (MOST) energy storage – Dewar Pyrimidone.", 2026. https://doi.org/10.59350/jhsbq-sfs70
- H.P.Q. Nguyen, A.J. Maertens, B.A. Baker, N.M. Wu, Z. Ye, Q. Zhou, Q. Qiu, N. Kaur, D.B. Berkinsky, K.E. Shulenberger, K.N. Houk, and G.G.D. Han, "Molecular solar thermal energy storage in Dewar pyrimidone beyond 1.6 megajoules per kilogram", Science, vol. 392, 2026. https://doi.org/10.1126/science.aec6413
- W.J. Theuer, and J.A. Moore, "Heterocyclic studies. The photoisomerization of 2,3-dihydro-5-methyl-6-phenyl-4H-1,2-diazepin-4-one and derivatives", Chemical Communications (London), pp. 468, 1965. https://doi.org/10.1039/c19650000468