Internal rotation around the isopropyl-nitrogen bond and stable conformations of S-methyl-N,N-di-isopropyldithiocarbamate, dichlorotin(IV) bis(N,N-di-isopropyldithiocarbamate) and related compounds
✍ Scribed by Toshio Tanaka; Noriyoshi Watanabe
- Publisher
- John Wiley and Sons
- Year
- 1974
- Tongue
- English
- Weight
- 477 KB
- Volume
- 6
- Category
- Article
- ISSN
- 0749-1581
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✦ Synopsis
Abstract
Temperature dependent proton magnetic resonance spectra of dichloro‐ and dimethyltin(IV) bis(N,N‐di‐isopropyl‐dithiocarbamate) (1 and 2, respectively), dimethylchlorotin(IV) N,N‐di‐isopropyldithiocarbamate (3), dimethyltin(IV) bis(N‐isopropyldithiocarbamate) (4), S‐methyl‐N,N‐di‐isopropyldithiocarbamate (5) and S‐methyl‐N‐isopropyldithiocarbamate (6) were measured in halogenated hydrocarbons or CS~2~. The internal rotation around the isopropyl–nitrogen bond of 1, 2, 3 and 5 is restricted below −30°C, and that of 4 and 6 below −70°C; 1, 2 and 3 exist as only one conformer in dichloromethane, while 5 exists as two rotational isomers with respect to the isopropyl–nitrogen bond with a mole ratio of about 2·7:1·0 in CS~2~ below −30°C. At this temperature, 6 exists as two stereoisomers in CS~2~ with a mole ratio of about 1·2:1·0, although there is no stereoisomer in 4. From these results, possible conformations of the compounds at low temperature are proposed and the assignments of each proton signal are described.