2026-06-27T23:02:30Zhttps://docta.ucm.es/rest/oai/request
oai:docta.ucm.es:20.500.14352/344842024-09-24T13:56:17Zcom_20.500.14352_14col_20.500.14352_15
Docta Complutense author García Martínez, Antonio author Moya Cerero, Santiago de la author Osío Barcina, José De Jesús author Moreno Jiménez, Florencio author Lora Maroto, Beatriz 2023-06-19T13:49:34Z 2023-06-19T13:49:34Z 2013-08-01 1434-193X 10.1002/ejoc.201300834 https://hdl.handle.net/20.500.14352/34484 https://doi.org/10.1002/ejoc.201300834 Several models, theoretical levels and computational methods, all based on the canonical variational transition state approximation, have been used to predict both the experimental activation energies (ΔEexp≠) and the experimental activation free energies (ΔGexp≠) for the hydrolysis of aryldiazonium ions. It is demonstrated that the computation of activation energies (ΔE≠), instead of activation free energies (ΔG≠), agrees better with the corresponding experimental data, showing that the employed computational methods do not afford reliable entropic contributions to the free energy barriers in the case of the studied reaction. However, the most fitted computations of ΔE≠ were not able to clearly differentiate between the mechanisms proposed for this interesting reaction (SN1, SN2 and water cluster). In contrast, the use of the Marcus theory (hyperbolic-cosine equation) instead of the canonical variational transition state theory leads to excellent agreement between the in-water-computed activation energies (ΔEwM≠) and the corresponding ΔEexp≠ values for the SN2 mechanism, but far beyond the limit of error for the SN1 process. The validity of the Marcus theory for the studied SN1 and SN2 reactions is ensured by the fact that both reactions can be described as SET processes. On the other hand, apparently compelling evidence against the SN2 mechanism, such as 13C KIEs and experimental observation of N2 scrambling, are also discussed and alternative explanations are proposed. eng The Mechanism of Hydrolysis of Aryldiazonium Ions Revisited: Marcus Theory vs. Canonical Variational Transition State Theory journal article URL https://docta.ucm.es/bitstreams/f7cecd1f-8998-4ed7-8882-2a4e18071cad/download File MD5 557878c9780505f4487c8b4890871942 411378 application/pdf European J Organic Chem - 2013 - Garc a Mart nez - The Mechanism of Hydrolysis of Aryldiazonium Ions Revisited Marcus.pdf