ISSN:
0749-1581
Keywords:
Naphthazarin polymorphs
;
Solid methylnaphthazarins
;
13C CP-MAS spectroscopy
;
Proton transfer in the solid state
;
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The high-resolution 13C solid-state NMR spectra of naphthazarin polymorphs and some of its derivatives having methyl substituents are discussed. Differences observed between the spectra of the A and B forms and that of the C modification of naphthazarin are explained by invoking hydrogen-bonding effects. The 2-methyl and 2,3-dimethyl derivatives show spectra consistent with their x-ray-determined structure as being mainly composed of the tautomer bearing the substituents on the quinonoid ring. The 2,7-dimethyl-substituted compound undergoes a fast intramolecular proton migration at room temperature between tautomers present in nearly equal amounts.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1260280206
Permalink
