Two new methylpolyynes, CH 3 (C'C) 6 H (tridecahexayne) and CH 3 (C'C) 7 H (pentadecaheptayne), have been detected in a supersonic molecular beam by Fourier transform microwave spectroscopy. A total of 20 transitions of CH 3 (C'C) 6 H in the K ϭ 0 and 1 rotational ladders and 8 transitions of CH 3 (
Microwave Spectra of the Methylpolyynes CH3(C≡C)4H and CH3(C≡C)5H
✍ Scribed by M.J. Travers; W. Chen; J.-U. Grabow; M.C. McCarthy; P. Thaddeus
- Publisher
- Elsevier Science
- Year
- 1998
- Tongue
- English
- Weight
- 122 KB
- Volume
- 192
- Category
- Article
- ISSN
- 0022-2852
No coin nor oath required. For personal study only.
✦ Synopsis
Following the laboratory detection by Fourier transform microwave spectroscopy of the four new methylcyanopolyynes described in the accompanying paper by W. Chen et al. (J. Mol. Spectrosc. 1998), we detected two new methylpolyynes, CH3(C identical withC)4H and CH3(C identical withC)5H. The strongest lines of both molecules, obtained in a discharge with a dilute mixture of methylacetylene and diacetylene in neon, were quite intense: after 4 min of integration, a signal to noise of about 300 for the strongest lines of CH3(C identical withC)4H and 30 for those of CH3(C identical withC)5H. Enough rotational transitions from the K = 0 and 1 ladders were detected in either molecule to be confident of the identification and to determine the rotational and leading centrifugal distortion constants to high accuracy. Like other carbon chains, the two here may be important in combustion processes and may be detectable in the interstellar gas, where the two shortest methylpolyynes have already been observed. Copyright 1998 Academic Press.
📜 SIMILAR VOLUMES
## Abstract A facile synthesis of the title compounds 2 and 3 is described. The key intermediate in the synthesis, 6‐demethyl‐7,7‐(ethylenedioxy)‐6‐(phenylselenenyl)mitosane (4) was synthesized in five steps from mitomycin A. Treatment of 4 with [^14^C]methyl iodide in the presence of K~2~CO~3~ aff
The ground state rotational spectra of four methylcyanopolyynes CH 3 (C'C) 2 CN, CH 3 (C'C) 3 CN, CH 3 (C'C) 4 CN, and CH 3 (C'C) 5 CN were measured between 6 and 22 GHz by Fourier transform microwave spectroscopy. For CH 3 (C'C) 2 CN, previously observed by Alexander et al. [J. Mol. Spectrosc. 70,
Study of n-butane pyrolysis at high temperature in a flow system allows measurement of the sum of the rate constants of the initiation reactions (2) and of the Arrhenius parameters of the reactions Established data for kl/k2 allow estimation of kl for 951'K and this, with recent thermochemical da