17O NMR chemical shifts of 3-(substituted methylene)-(Z)-1(3H)-isobenzofuranones: correlations with IR stretching wavenumbers and AM1 charges
✍ Scribed by Erkki Kolehmainen; Kari Lappalainen; Alexander Perjéssy; Pavol Hrnčiar; Margita Lácová; Walter M. F. Fabian
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 178 KB
- Volume
- 36
- Category
- Article
- ISSN
- 0749-1581
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✦ Synopsis
17O NMR chemical shifts were determined for 1(3H)-isobenzofuranone, its 3-methylene-and 3-(Z)-(methylmethylene) derivatives and a series of 3-aryl-, 3-aryloxy-and 3-arylthiomethylene-(Z)-1(3H)-isobenzofuranones. The observed d(17O) values of the CxO-group of the furanone moiety in the arylidene series show signiÐcant linear dependences on the wavenumber of the IR stretching vibration, l(CO), the AM1 charge density at the double bond oxygen, q(O), and the Hammett p`constant of the substituent in the phenyl ring. These Ðndings suggest that the substituent e †ects are efficiently transmitted from the phenyl ring to the CxO group via the conjugated double bond system of the 3-arylidene-(Z)-1(3H)-isobenzofuranone. In the case of aryloxy and arylthio derivatives these correlations were less signiÐcant than in arylidene compounds, reÑecting the diverse e †ects of the heteroatoms (O or S) on the transmission mechanism.