Towards a consensus structure of hypericin in solution: direct evidence for a single tautomer and different ionization states in protic and nonprotic solvents by the use of variable temperature gradient H-1 NMR
Towards a consensus structure of hypericin in solution: direct evidence for a single tautomer and different ionization states in protic and nonprotic solvents by the use of variable temperature gradient H-1 NMR
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Skalkos, D.
(EN)
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας
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Skalkos, D.
(EN)
Hypericin, a meso-naphthodianthrone derivative, displays two types of electronic spectra in organic solvents, attributed to the existence of two tautomeric structures. Variable temperature gradient H-1 NMR studies demonstrate the occurrence of only one 7,14-dioxo tautomeric form, for the molecule of hypericin in protic and in nonprotic solvents, differing only in the degree of ionization of the 4-hydroxyl group in the bay region. (C) 2002 Elsevier Science Ltd. All rights reserved.
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