Fulvene, VII. Analyse der 13C‐ und 1H‐NMR.‐Spektren

Carbon‐13 and proton NMR. spectra of pentafulvene and of a series of 6‐substituted fulvenes have been analysed and assigned by homo‐ and heteronuclear double resonance and with the aid of iterative computation. 13C and 1H chemical shifts are interpreted in terms of substituent effects and compared with π‐electron charges calculated for the unsubstituted fulvene. From 13C shifts a 10 percent contribution of dipolar structures to the electronic configuration of fulvene may be estimated. All long‐range proton‐proton coupling constants including relative signs and some proton‐carbon couplings in the fulvene spin system have been determined and assigned.