Tieftemperatur 13C-NMR.-Spektren von 13C-und 6Li-markierten Chlor-, Brom- und Jod-Lithium-Carbenoiden. Vorläufige Mitteilung
✍ Scribed by Dieter Scebach; Herbert Siegel; Josef Gabriel; Robert Hässig
- Publisher
- John Wiley and Sons
- Year
- 1980
- Tongue
- German
- Weight
- 343 KB
- Volume
- 63
- Category
- Article
- ISSN
- 0018-019X
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✦ Synopsis
Low Temperature ^13^C‐NMR. Spectra of ^13^C‐ and ^6^Li‐Labelled Chloro‐, Bromo‐, and Iodo‐lithiumcarbenoids
The ^13^C‐NMR. spectra of tetrahydrofuran solutions of 16 chloro‐, bromo‐, and iodo‐^6^lithio‐ and ‐^7^lithio‐carbenoids with ^13^C‐labelled methane, ethane, ethylene, and cyclopropane C‐skeletons have been measured at temperatures around − 100° (for examples see Fig. 1 and 2). Invariably, the exchange of hydrogen or halogen by lithium causes deshielding (Δδ, see Table 1) of the ^13^C‐signal by up to 289 and 434 ppm, respectively, and decrease of ^1^J (^1^H, ^13^C) and ^1^J(^13^C,^13^C) couplings (see Table 2) with the C‐atom of up to 104 and 30 Hz, respectively. The ^1^J(^6^Li, ^13^C) and ^1^J(^7^Li, ^13^C) coupling of ca. 17 and 45 Hz, respectively, obtained in ten cases (Table 1) is independant of the substitution pattern of the C‐skeleton and of the particular halogen atom.