title: Small carbon-carbon couplings in monosubstituted benzenes--their signs and magnitudes determined by HCSE method.
abstract: Signed values of all intra-ring (2,3,4) J(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 (3)J(C,C) are positive and all geminal (2)J(C2,C4) are negative, both signs are found for geminal (2)J(C1,C3) couplings. All the determined signs agree with those already predicted by theoretical calculations.
authors.affiliation: Institute of Chemical Process Fundamentals of the ASCR, v.v.i., Prague 6, Czech Republic. Blechta@icpf.cas.cz
authors.forename: Vratislav
authors.initials: V
authors.lastname: Blechta
authors.forename: Jan
authors.initials: J
authors.lastname: Schraml
mesh_terms: D001555:Benzene Derivatives / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000592:standards; D012015:Reference Standards
chemical_list: D001555:Benzene Derivatives; D002244:Carbon