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13 C NMR and structural study of solid state naphthol‐1 and naphthol‐2 arylazo‐derivatives
Author(s) -
Fedorov L.A.,
Rebrov A.I.,
Hu JianZhi,
Shen LianFang
Publication year - 1991
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.19910090308
Subject(s) - tautomer , chemistry , 1 naphthol , naphthalene , 2 naphthol , solid state , ring (chemistry) , carbon 13 nmr , conformational isomerism , crystallography , spectroscopy , nuclear magnetic resonance spectroscopy , aryl , computational chemistry , stereochemistry , molecule , organic chemistry , physics , alkyl , quantum mechanics
Solid state 13 C NMR spectra of a series of naphthol‐1 and naphthol‐2‐arylazo‐derivatives were studied and compared with respective results in solutions. Signals of carbon nuclei of naphthalene ring were assigned. Tautomeric forms of compounds were determined. It was shown that 4‐( p ‐NO 2 C 6 H 4 )‐azonaphthol‐1 and 1‐( p ‐NO 2 C 6 H 4 )‐azonaphthol‐2 in solid state existed exclusively in quinohydrazone form. The other two compounds—1‐(C 6 F 5 )‐azonaphthol‐2 and 2‐( p ‐CH 2 C 6 H 4 )‐azonaphthol‐1 in solid state were not found in the form of individual tautomeric mixtures but in respective tautomeric equilibrium form. Thus, during transition from liquid to solid state, the tautomeric equilibrium was practically unchanged. In solid state it was found that rotation around aryl‐N bond was hindered in the time scale of NMR spectroscopy.