| Popis: |
N.M.R. spectra of a few mono and disubstituted derivatives of dibenzo [g,p] chrysene have been recorded at 60 Mc. The N.M.R. data proved decisive in solving an ambiguity which resulted from chemical degradations and thus in localizing the positions of substitution in this polycyclic aromatic system. The two types of angular protons, which cannot be distinguished in the spectrum of dibenzo [g,p] chrysene, give rise to two distinct signals in the spectrum of quinone VII (H‐α3− and H‐α4− singlets separated by 4 c/s). The N.M.R. spectrum of tetrabenzo[b,g,k,p] chrysene VIII shows the same apparent anomaly as that observed earlier in dibenzo [g,p] chrysene, that is the quasi‐identity of angular protons of different types (H‐γ3 and H6‐γ4). Copyright © 1964 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim |
