Carbon-13 n.m.r. study of 31P13C spin–spin coupling constants in dichloro- and monochloro-vinyl phosphate derivatives

✍ Scribed by Gábor Szalontai

• Publisher: John Wiley and Sons
• Year: 1977
• Tongue: English
• Weight: 383 KB
• Volume: 10
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/mrc.1270100117

✦ Synopsis

Carbon

-13 chemical shifts and J(PC) coupling constants of 29 vinyl phosphate derivatives are presented. In the series of compounds (RIO)zP(0)OC'(R~)=CzX, (where 3 R: indicates the first carbon of the Rz substituent) large differences were found between the 3J(P, 0, C-1, C-3) and 3J(P, 0, C-1, C-2) coupling constants of the chlorinated (X=Cl) and the unsubstituted (X=H) derivatives. A possible explanation of this phenomenon is given on the basis of Jameson's s bond character theory. Strong stereospecificity of 3J(P,0,) coupling constants was observed in the series of compounds (R,O)z P(0)OC1(R:)=CZHR3. Coupling constants varied between 3.2-4.9 Hz in the E isomers, while peaks could not be resolved in the Z isomers. The 'J(P, 0, C-1, C-2) coupling constants were regularly 20-30% greater in the Z than in the E isomers.

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