The determination of the COOH substiuent effect for branched carboxylic acids from carbon‐13 chemical shifts

Abstract

The carboxyl substituent effects for branched carboxylic acids have been determined by carbon-13 Fourier transform nuclear magnetic resonance of eighteen measured and reported branched acids. For a-branched systems the substituent effects are 01 = 15.3 ppm, p = 2.6 ppm, y = -1.9 ppm, S = 0.9 ppm and E = 0.5 ppm. For other branched acids, the determined carboxyl substituent effects are a = 19.2 ppm, p = 2.1 ppm, y = -1.4 ppm, S = 0.6 ppm, and CE = 0.6 ppm.

Carbon‐13 NMR spectra and the method for their calculation for long‐chain polybranched carboxylic acids and their derivatives

“…The synthetic procedures, physical characteristics and structural identification of the compounds have been described earlier. " The most reliable 13C NMR signals were used in calculating the coefficients in Eqn (4). The values N Table 1.…”

NMR Spectra of Organogermanium Compounds tuted 1‐Trichlorogermylethanes 2‐13c NMR spectra of 2‐substituted 1‐Trichlorogermylethanes

“…CH, 0 -6.76 -12.51 -3.61 -3.48 2 9 COCH, 0 -6.64 -12.81 -3.30 -4.00 3 10 CH, NOH -6.85 -14.14 -4.50 -2.76 4 11 CH, NOCOCH, -6.38 -13.87 -4.27 -3.23 5 12 COCH, NOCOCH, -6…”