Small carbon-carbon couplings in monosubstituted benzenes - their signs and magnitudes determined by HCSE method

• Published in: Magnetic resonance in chemistry 2013-06, Vol.51 (6), p.378-381
• Main Authors: Blechta, Vratislav, Schraml, Jan
• Format: Article
• Language: English
• Subjects: 13C; Benzene Derivatives - chemistry; Carbon; Carbon - chemistry; Carbon-carbon composites; carbon-carbon coupling; coupling sign; Couplings; HCSE; INADEQUATE; Magnetic resonance; Magnetic Resonance Spectroscopy - standards; Mathematical analysis; monosubstituted benzenes; Nitrogen dioxide; NMR; Reference Standards; SLAP
• ISSN: 0749-1581; 1097-458X
• DOI: 10.1002/mrc.3954

Signed values of all intra‐ring 2,3,4J(C,C) couplings in nine monosubstituted benzenes (C6H5‐X where X = F, Cl, Br, CH3, OCH3, Si(CH3)3, C ≡ N, NO, NO2) are experimentally determined as well as nine couplings to substituent carbons. It is confirmed that while all the vicinal intra‐ring 3J(C,C) are positive and all geminal 2J(C2,C4) are negative, both signs are found for geminal 2J(C1,C3) couplings. All the determined signs agree with those already predicted by theoretical calculations. Copyright © 2013 John Wiley & Sons, Ltd. Signed values of all intra‐ring 2,3,4J(C,C) couplings in nine monosubstituted benzenes (C6H5‐X where X = F, Cl, Br, CH3, OCH3, Si(CH3)3, C ≡ N, NO, NO2) are experimentally determined as well as nine couplings to substituent carbons. It is confirmed that, although all the vicinal intra‐ring 3J(C,C) are positive and all geminal 2J(C2,C4) are negative, both signs are found for geminal 2J(C1,C3) couplings. All the determined signs agree with those already predicted by theoretical calculations.