Molecules of the year: 2026 – vote!

The annual C&E News poll on “molecules of the year” is under way and you are encouraged to vote for one. Having taken a quick look at each of the candidates, I normally see if I can add any “value” to the originals by performing appropriate calculations (e.g. [1] and many others). This year, I cannot help but note that most of the candidates already report pretty good quality calculations of this type, thus limiting my scope for adding such value. It is a sign of the times that appropriate modelling is now a sine qua non for reports of many novel and interesting new molecules. In the citations below, I have taken the liberty of adding related references for some earlier precedents from our own work.‡

  1. Boron buckyball [2] (see this 2009 article on B60[3]).
  2. ‘Impossible’ hydroxy oxonium [4] (see this 2016 article on such oxonium ions as intermediates in natural product synthesis.[5])
  3. Aromatic silicon ring [6],[7] (see this 2010 precedent for an aromatic silicon ring[8])
  4. Secaloside stereochemistry revealed [9]
  5. Superstrained cubic alkene [10], [1]
  6. Colorful copper sandwiches [11],[12]

‡Since around 2012, I have been adding references to my blog posts, in the time honoured scientific tradition. If you look at the inventory of the 878 or so such posts, I am very proud that currently 65.3% of them have at least one such reference. It is not that common amongst science blogs unfortunately (only ~5.9%). I encourage all who write science-based posts to add such references, and of course to cite other blogs using a DOI assigned to it by e.g. Rogue Scholar.

Author

References

  1. H. Rzepa, "Molecules of the Year 2024: A crystal structure perspective on anti-Bredt olefins.", 2025. https://doi.org/10.59350/dxkyx-8nb67
  2. H.W. Choi, Y. Zhang, D. Kahraman, C. Xu, H. Gao, J. Li, and L. Wang, "Boron buckminsterfullerene", Chemical Science, vol. 17, pp. 12871-12876, 2026. https://doi.org/10.1039/d6sc02674e
  3. H.S. Rzepa, "The distortivity of π-electrons in conjugated boron rings", Physical Chemistry Chemical Physics, vol. 11, pp. 10042, 2009. https://doi.org/10.1039/b911817a
  4. A.L. Otsuki, G.A. Alkan, S. Manabe, W.T. Shewa, G. Gunbas, J.C. Fettinger, M. Mascal, and N. Hafezi, "A Hydroxy‐Substituted Trialkyloxonium Ion and Its Oxonium Alkoxide Zwitterion", Angewandte Chemie International Edition, vol. 65, 2026. https://doi.org/10.1002/anie.2727232
  5. J. Clarke, K.J. Bonney, M. Yaqoob, S. Solanki, H.S. Rzepa, A.J.P. White, D.S. Millan, and D.C. Braddock, "Epimeric Face-Selective Oxidations and Diastereodivergent Transannular Oxonium Ion Formation Fragmentations: Computational Modeling and Total Syntheses of 12-Epoxyobtusallene IV, 12-Epoxyobtusallene II, Obtusallene X, Marilzabicycloallene C, and Marilzabicycloallene D", The Journal of Organic Chemistry, vol. 81, pp. 9539-9552, 2016. https://doi.org/10.1021/acs.joc.6b02008
  6. B. Morgenstern, and D. Scheschkewitz, "Pentasilacyclopentadienide: A Hückel aromatic species at the border of resonance and equilibrium", Science, vol. 391, pp. 579-582, 2026. https://doi.org/10.1126/science.aed1802
  7. T. Iwamoto, T. Ishikawa, and S. Ishida, "Silicon cyclopentadienides featuring a nonplanar 6π aromatic Si <sub>5</sub> ring", Science, vol. 391, pp. 587-591, 2026. https://doi.org/10.1126/science.aed0168
  8. K. Abersfelder, A.J.P. White, H.S. Rzepa, and D. Scheschkewitz, "A Tricyclic Aromatic Isomer of Hexasilabenzene", Science, vol. 327, pp. 564-566, 2010. https://doi.org/10.1126/science.1181771
  9. Y. Nam, A.T. Tam, T.E. Reynolds, D.N. Rojas, J.A. Brekan, S. Sil, and K.A. Scheidt, "Synthesis and Structural Confirmation of Secalosides A and B", Journal of the American Chemical Society, vol. 148, pp. 86-92, 2025. https://doi.org/10.1021/jacs.5c18864
  10. J. Ding, S.A. French, C.A. Rivera, A. Tena Meza, D.C. Witkowski, K.N. Houk, and N.K. Garg, "Hyperpyramidalized alkenes with bond orders near 1.5 as synthetic building blocks", Nature Chemistry, vol. 18, pp. 913-922, 2026. https://doi.org/10.1038/s41557-025-02055-9
  11. J.D. Queen, R. Grotjahn, L. Garcia, G. Rao, A.A. Shiau, R.D. Britt, J.W. Ziller, F. Furche, and W.J. Evans, "Isolable Cuprocenes: Bis(tri- <i>tert</i> -butylcyclopentadienyl) Complexes of Copper", Journal of the American Chemical Society, vol. 148, pp. 5462-5475, 2026. https://doi.org/10.1021/jacs.5c19366
  12. H. Rzepa, "Molecules of the year 2023 – part 2. A FAIR data comment on a Strontium Metallocene.", 2023. https://doi.org/10.59350/cvzze-k0171

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