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Combined application of auto‐correlated (COSY) and homonuclear J‐resolved two‐dimensional NMR spectra for the assignment of congested, non‐first order spectra of polycyclic aromatic systems. Assignment of the 1 H‐NMR spectrum of benzo[2,3]phenanthro‐[4,5‐ bcd ]thiophene and an investigation of long range 1 H‐ 1 H spin‐coupling constants
Author(s) -
Musmar M. J.,
Gampe Robert T.,
Martin Gary E.,
Layton W. John,
Smith Stanford L.,
Thompson Robert D.,
Iwao Masatomo,
Lee Milton L.,
Castle Raymond N.
Publication year - 1984
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570210145
Subject(s) - homonuclear molecule , chemistry , spectral line , nuclear magnetic resonance spectroscopy , proton , carbon 13 nmr satellite , spectroscopy , spins , nmr spectra database , two dimensional nuclear magnetic resonance spectroscopy , proton nmr , fluorine 19 nmr , stereochemistry , molecule , physics , nuclear physics , organic chemistry , quantum mechanics , astronomy , condensed matter physics
Total assignment of the proton nmr spectrum of benzo[2,3]phenanthro[4,5‐ bcd ]thiophene at 200 MHz is reported. Preliminary identification of the resonances comprising the individual spin Systems was accomplished by the use of auto‐correlated two‐dimensional proton nmr spectroscopy (COSY). Individual assignments were made on the basis of spin‐coupling information which was obtained from the “titled” two‐dimensional J‐resolved (2DJ) proton nmr spectrum of the title compound. Because of the greater resolving power of the latter experiment relative to conventional proton nmr spectroscopy, a number of long range inter‐ring spincouplings were observed. The observation of these long range couplings was crucial to the final assignment of several of the resonances in the spectrum. Resonances due to strong coupling in the 2DJ spectrum were also shown to be a useful means of correlating strongly coupled spins which provides an alternative to the COSY spectrum for this purpose.