Replication Data for: Spectroscopic Characterization and Electrocyclic Ring Opening of Parent 2-Azetine

PROJECT DESCRIPTION:
(N-Boc)-protected 2-azetine serves as a suitable precursor for the generation of parent 2-azetine. High-vacuum flash pyrolysis experiments at 200 °C induce the deprotection of the (N-Boc)-protected 2-azetine resulting in the release of carbon dioxide and isobutene allowing the trapping of 2-azetine in a solid argon matrix at 3 K and its spectroscopic characterization by infrared spectroscopy. The assignment is supported by isotopic labeling experiments and excellent agreement with anharmonic vibrational frequencies calculated at the B2PLYP-D3/def2-TZVPP level of theory. At elevated pyrolysis temperatures, 2-azetine undergoes selective ring opening to yield 1-azabutadiene, for which both s-trans-(E) and s-trans-(Z) conformers are observed. Computed reaction pathways and free-energy profiles rationalize the temperature-dependent product distribution and the observed torquoselectivity. These results provide fundamental insight into the structure, stability, and reactivity of 2-azetine and establish matrix isolation as a powerful approach for accessing highly strained nitrogen heterocycles.
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DATASET DESCRIPTION:
This dataset contains experimental IR and NMR spectra and optimized geometries published in the main manuscript and Supporting Information (SI). <br>
IR labeled as 'Figure...' are presented in the appropriate figures in the main text or the SI. All captions follow the structure: Figure → compound name_number→ Matrix → (process). All NMR Spectra are labeled as 'Figure...' and the caption follows the structure: '1H/13C_NMR_compound-name'. <br>
Optimized geometries including electronic energies and thermal corrections are provided in the Coordinates_Energies.xyz file.