Substituenteneffekte auf die NMR-Spektren von Pentafulvenen. (13C, 13C)-NMR-Kopplungskonstanten (1J(C, C))

✍ Scribed by Hansruedi Bircher; Markus Neuenschwander

• Publisher: John Wiley and Sons
• Year: 1989
• Tongue: German
• Weight: 427 KB
• Volume: 72
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.19890720806

✦ Synopsis

Substituent Effects on NMR Spectra of Pentafulvenes. I3C,l3C-NMR Coupling Constants ('J(C,C))

'Hand I3C-NMR spectra of 6-monosubstitued pentafulvenes 1-8 have been analysed, and 'J(C,C) coupling constants have been determined from 1D-inadequate spectra of I3C satellites. It turns out that I3C,I3C coupling constants of the ring C-atoms, and especially J(1,2)/J(3,4) and J(2,3), reflect the extent of R delocalisation in the fulvene ring. With increasing electron-donating capacity of the substituent R, J(1,2)/J(3,4) values are decreasing, while J(2,3) (and J(1,5)/J(4,5) as well) are increasing, and linear correlations of Hummetf substituent constants u+ and 'J(C,C) values are obtained.

')

2, 57. Mitteilung iiber Fulvene, Fulvalene; 56. Mitteilung: [I]. Analoge Befunde fur 6-Methyl-6-0, -X-pheny1)pentafulvene wurden nach dem Erscheinen unserer Kurzmitteilung [6] von Surdellu et ul. [7] veroffentlicht.