This candidate[1] for “MOTY 2026” has the unusual feature of containing both a trialkyl oxonium cation and an alkoxide counterion present in the same species (11z below).
References
- 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