Carbon-13 nuclear magnetic resonance spectrometry. Chemical shifts for the paraffins through C9

Additivity Parameters for Organotin 13C Chemical Shifts

“…Such effects have been discussed at length in the literature. The development of a more extensive set of branching corrections, such as those of Lindeman and Adams (6), is not warranted since only the neophyl group appears t o be affected in our series of compounds. The isobutyl group (see below, require a smaller upfield correction at the tertiary carbon atom.…”

Microstructure of Copolymers of Norbornene Based on Assignments of 13C NMR Spectra: Evolution of a Methodology

“…Resonances assignable to pendant double bonds (Vy), which are due to HED polymerization without cyclization, were assigned to unsaturated carbon atoms appearing in the region between 110 and 150 ppm. Thus, signals at 112.1 and 137.6 ppm were attributed to the side chain double bond carbon atoms 4B 4 and 3B 4 sketched in Scheme 10. These assignments allow us to conclude that 1,5-hexadiene can be incorporated into the polymer chain as 1-butenyl branches (Vy) or in the form of cyclopentane structures (CP) connected at C 1 and C 3 positions to the polymer backbone and to calculate compositions of poly(E-ter-N-ter-HED) on the basis of the peak integrals of carbons in the 13 C NMR spectra.…”

Genesis of structural features of humic acids from the sediments of a high productive coastal zone

“…13 C-NMR spectra characterization The peak at 29.7 ppm in the aliphatic region is dominated and is mainly produced by (CH 2 ) n fatty acid chains (Hatcher et al, 1981;Lindeman and Adams, 1971). Among the six regions considered, alkyl carbon components (such as methyl, methylene and methine carbons) in the 0-45 ppm region constitute a major structural moiety of the HAs of mudbank sediments.…”