C-NMR Spectra

Figure 7. C-13 NMR spectrum of reaction products asymmetric octahydrophenanthrene plus di-...

Figure 9. Partial C-13 NMR spectrum of thermally stable Tetralin adducts (9)...

Figure 6. Assignment of resonances in C-13 NMR spectrum of low-molecular-weight polymer from 2,4,6-trichlorophenoxide...

Figure 1. Pulsed FT C-13 NMR spectrum of (a) a 71 wt. % C,Hi and (b) a 56 wt % CiHi EPDM rubbers obtained at 393 K from a trichlorobenzene solution. (Figure lb reproduced from Ref. 11.)...

Figure 4. Pulsed FT C-13 NMR spectrum of the polyalkane obtained by hydrogenating an alternating propylene butadiene copolymer made with a titanium catalyst, Copolymer B. The spectrum was obtained at ambient temperature from...

Figure 6. Magic angle spinning, high-power proton decoupling, FT C-13 NMR spectrum of cured, carbon-black-loaded polyisoprene at ambient temperature, FT of normal FID without proton enhancement.

Figure 1. H-NMR spectrum at 220 MHz (upper) and C-13 NMR spectrum at 22.63 MHz (lower) of hyaluronic acid (sodium salt) in D O solution. Descriptions of analogous spectra are given in Ref. 3 ( H) and Ref. 4 (C-13).

Figure 5. Proton noise-decoupled 22.6-MHz C-13 NMR spectrum of the hydrogenated 1,4-polyisoprene sample. Perdeuteriohenzene solution at 25°C with TMS as internal reference. Approximately 5000 pulses with an acquisition time of 0.7 sec and a flip angle of 30°.

Figure 4. Partial C-13 NMR spectrum of a THF-CHaOSOsF (2.5 1) polymerization mixture in CH3NO2 (45.5% ) after addition of diethyl ether (2.5)...

Figure 1. Methyl, methine, and methylene regions of the C-13 NMR spectrum of...

Figure 2. The methylene and methine regions of the C-13 NMR spectrum of PS prepared with a free radical initiator. The internal standard is HMDS, which occurs at 2.03 ppm with respect...

As can be seen from Fig 2b, the solid state C-13 nmr spectrum of T. aestivum also shows sets of enhanced resonances at 61 ppm and 169.6-174.9 ppm respectively (24). However, their relative intensities are very different from that observed for L. leucocephala. Indeed, it can immediately be seen that very little reduction of the administered precursor to hydroxymethyl analogues (at 61 ppm) has occurred. On the other hand, the dominant resonances at 169.6 and 174.9 ppm are coincident with bound hydroxycin-namic acids (e.g. ferulic 5a) and its esters (31). Subsequent analysis of its isolated acetal lignin derivative (32) indicated that much of the lignin contained hydroxycinnamate residues (33). 

Figure 12. Modification of charge density on carbon atoms of benzylpicolyl-magnesium calculated from C-13 NMR spectrum (a) Ref. 10 (b) Ref. 9 (c) Ref. 8.

While most vinyl ketones readily undergo radical polymerization, and can only be stored in the monomeric state if an inhibitor is present, this enone failed to polymerize with either benzoyl peroxide or azobisisobutyronitrile under a variety of conditions. Examining the C-13 NMR spectrum of the monomer provides some insight into the lack of reactivity displayed by this unsaturated ketone. 

Fig. 6. C-13 NMR Spectrum of Reaction Mass of Heated Mixture of 1,2-epoxy butane, diphenyl-methyl silanol and Alfacach 501.

Samples taken from the acrylamide copolymer and taurine reaction mixture were analyzed. A typical C-13 NMR spectrum is shown in Figure 1. It exhibits an acrylate multiplet at 184 ppm, an acrylamide multiplet at 180 ppm and a multiplet at about 178 ppm for both secondary amide and imide carbonyls. The methylene from the sulfoethylamide attached to sulfonate occurs at 50 ppm while the methylene attached to the amide nitrogen overlaps with the methylene of the backbone but is observable at 36 ppm. The methylene of taurine attached to the sulfonate occurs at 49 ppm while the other methylene occurs with the backbone methylene signal. The backbone methine signal for the acrylate portion of the polymer occurs at 46 ppm while the backbone methine signal for the amide occurs at 44 ppm. 

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