Résumé : NMR spectra of benzo [b] biphenylene and of substituted biphenylenes, benzo [a] biphenylenes and benzo [b] biphenylenes have been recorded at 60 Mc. These spectra fully confirm the structures previously assigned to the twelve derivatives examined in this work. The expected spectraum of benzo [a] biphenylene is deduced from the spectra of its substituted derivatives. The main results are summarized. © 1964.