Spin–spin coupling constants as indicators of the conformation of anthrone in solution
Keyword(s):
H Nmr
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The analyses of the 1H nmr spectra of fluorene, 2,7-dibromofluorene, and anthrone are reported. The benzylic couplings in these compounds are compared with those in indene and toluene. It is argued that the six-bond and five-bond couplings in anthrone are more compatible with a nonplanar than a planar central ring. The spectrum of the 2,7-dibromofluorene suggest that couplings between protons in different benzenoid rings are small, perhaps no larger than 0.05 Hz.