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Carbon‐13 NMR of quinone methides
Author(s) -
Benson Mabry,
Jurd Leonard
Publication year - 1984
Publication title -
organic magnetic resonance
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0030-4921
DOI - 10.1002/mrc.1270220206
Subject(s) - quinone , chemistry , chemical shift , quinone methide , carbon fibers , oxygen , hydrogen , nuclear magnetic resonance spectroscopy , photochemistry , hydrogen bond , molecule , organic chemistry , materials science , composite material , composite number
The 13 C NMR spectra of four ortho ‐ and seven para ‐quinone methides were assigned using chemical shift and long‐range carbon‐proton coupling information. The carbonyl shifts are compared with those in ortho ‐ and para ‐benzoquinones. The chemical shifts of the carbonyls of the p ‐quinone methides are observed at δ 186.2–186.4 for the three ortho ‐di‐ tert ‐butyl‐substituted compounds and at δ 180.7–181.5 for the four ortho ‐oxy‐substituted compounds. In the three o ‐quinone methides with meta , para ‐dioxy substituents, the carbonyl signals are at δ 184.2–185.4. The carbonyl signal of the one o ‐quinone methide with no oxygen substitution is shifted downfield to δ 200.9, apparently as a result of hydrogen bonding to the nearby hydroxyl.