Molecular Structure and Large-Amplitude Motion of p-Diethynylbenzene from Gas-Phase Electron Diffraction and Theoretical Calculations
| العنوان: | Molecular Structure and Large-Amplitude Motion of p-Diethynylbenzene from Gas-Phase Electron Diffraction and Theoretical Calculations |
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| المؤلفون: | Fabio Ramondo, Anna Rita Campanelli, Gustavo Portalone, Antonio Arcadi, István Hargittai, Aldo Domenicano, György Schultz |
| المصدر: | Scopus-Elsevier |
| بيانات النشر: | American Chemical Society (ACS), 1996. |
| سنة النشر: | 1996 |
| مصطلحات موضوعية: | Chemistry, Gas-phase electron diffraction, Large-amplitude motion, p-diethynylbenzene, MO calculations, General Engineering, Ab initio, ELECTRON DIFFRATION, Motion (geometry), Bending, THEORETICAL CALCULATIONS, ALKYNES, Gas phase, Crystallography, Amplitude, Electron diffraction, Molecule, Physical and Theoretical Chemistry, Conformational isomerism |
| الوصف: | The molecular structure of p-diethynylbenzene has been determined by gas-phase electron diffraction and ab initio MO calculations at the HF/6-31G* and MP2/6-31G*(fc) levels. The two ethynyl groups undergo large-amplitude bending motions, making the equilibrium D2h model inadequate to describe the average structure from electron diffraction. Based on spectroscopic information on low-frequency modes, the electron diffraction data were approximated by a model consisting of a mixture of rigid conformers, differing only in the extent of the symmetric out-of-plane bending of the substituents. This gave the following geometrical parameters: ∠Cortho−Cipso−Cortho = 119.2 ± 0.2°, 〈rg(C−C)〉 = 1.402 ± 0.003 A, rg(Cring−Csp) = 1.431 ± 0.003 A, and rg(C⋮C) = 1.211 ± 0.003 A. The computed re values (MP2) are 119.2°, 1.401 A, 1.430 A, and 1.223 A, respectively, with the Cipso−Cortho bond 0.016 A longer than the central C−C bond. The HF/6-31G* geometries of ethynylbenzene and p-diethynylbenzene indicate that the interact... |
| تدمد: | 1541-5740 0022-3654 |
| الوصول الحر: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::196dadae50d306ce62028fb831f40198Test https://doi.org/10.1021/jp952328yTest |
| حقوق: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....196dadae50d306ce62028fb831f40198 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 15415740 00223654 |
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