title: HCSE method for detection of small carbon-carbon couplings and their signs, comparison with SLAP pulse sequence.
abstract: Performance of homonuclear coupling sign edited (HCSE) experiment applied to detection of signed carbon-carbon couplings is discussed using a set of already measured samples of nine monosubstituted benzenes. It is shown that coupling sign detection is insensitive to the settings of carbon-carbon polarization transfer delays. The HCSE spectra of ten from the total of 43 measured carbon-carbon couplings were considerably influenced by relaxations and proton-proton strong couplings. These effects are quantitatively discussed. The results of HCSE and SLAP experiments are compared. It is shown that the two methods may complement each other in detection of signed carbon-carbon couplings.
authors.affiliation: Institute of Chemical Process Fundamentals of the ASCR, v. v. i., 165 02, Prague 6, Czech Republic.
authors.forename: Vratislav
authors.initials: V
authors.lastname: Blechta
authors.forename: Jan
authors.initials: J
authors.lastname: Schraml
keywords: 13C; 1H; HCSE; INADEQUATE; NMR; SLAP; carbon–carbon coupling; coupling sign; monosubstituted benzenes; strong coupling