Details

Autor(en) / Beteiligte

• Esselman, Brian J
• Kougias, Samuel M
• Zdanovskaia, Maria A
• Woods, R. Claude
• McMahon, Robert J

Titel

Synthesis, Purification, and Rotational Spectroscopy of (Cyanomethylene)CyclopropaneAn Isomer of Pyridine

Ist Teil von

• The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory, 2021-07, Vol.125 (25), p.5601-5614

Ort / Verlag

American Chemical Society

Erscheinungsjahr

2021

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The gas-phase rotational spectrum of (cyanomethylene)­cyclopropane, (CH2)2CCHCN, generated by a Wittig reaction between the hemiketal of cyclopropanone and (cyanomethylene)­triphenylphosphorane, is presented for the first time. This small, highly polar nitrile is a cyclopropyl-containing structural isomer of pyridine. The rotational spectra of the ground state and two vibrationally excited states were observed, analyzed, and least-squares fit from 130 to 360 GHz. Over 3900 R-, P-, and Q-branch, ground-state rotational transitions were fit to low-error, partial octic, A- and S-reduced Hamiltonians, providing precise determinations of the spectroscopic constants. The two lowest-energy vibrationally excited states, ν17 and ν27, form a Coriolis-coupled dyad displaying small a- and b-type resonances. Transitions for these two states were measured and least-squares fit to a two-state, partial octic, A-reduced Hamiltonian in the Ir representation with nine Coriolis-coupling terms (G a , G a J , G a K , G a JJ , F bc , F bc J , F bc K , G b , and G b J ). The observation of many resonant transitions and nine nominal interstate transitions enabled a very accurate and precise energy difference between ν17 and ν27 to be determined: ΔE 17,27 = 29.8975453 (33) cm–1. The spectroscopic constants presented herein provide the foundation for future astronomical searches for (cyanomethylene)­cyclopropane.