Gated decoupling inverse

Solution N NMR spectra of N-enriched fungal material isolated from the composts were measured with broadband decoupling, inverse gated decoupling and DEFT pulse sequences.(d7,d4) A comparison of these spectra shows a high degree... 

Fig. 16a,b Carbon-13 spectra of compound 1 recorded at 50 MHz. a Standard spectrum with integral values (measurement time 1.5 hours) b inverse gated decoupled spectrum with integral values (measurement time 28 hours )... 

Fig. 17. NMR spectrum obtained using a single 90° pulse without H decoupling in pure DPPC bilayers at 50 °C and 1 bar (a) and P NMR spectra obtained using a fully phase-cycled Hahn echo sequence with inversely gated H decoupling in pure DPPC bilayers at 50 °C and 1 bar in the LC phase (b), 1 kbar in the GI phase (c), 1.75 kbar in the interdigitated Gi gel phase (d), 2.5 kbar in the GII gel phase (e), 3.7 kbar in the GUI gel phase (f), and 5.1 kbar in the GX gel phase (g) (after Refs. 4, 18).

The potential of carbon-13 NMR in the analysis of keto-enol tautomerism has been demonstrated for 2,4-pentanedione (acetylacetone) and dimedone [293]. Quantitative evaluation of equilibrium concentrations is possible by application of the inverse gated decoupling technique illustrated in Fig. 2.23. 

Keto-enol tautomerism of fi-keto esters can be analyzed by carbon-13 NMR as illustrated by an inverse gated proton-decoupled 13C NMR spectrum of ethyl acetoacetate in Fig. 4.6 [73 i]. 

ID 13C NMR N/A Can provide a quantitative overview as to the carbon distribution. In the case of NOM, often 2D NMR is central to the interpretation of the ID NMR, which often contains considerable overlap. For quantitative data, the recycle delay (dl) should be >5 x T1 for the slowest relaxing component in the sample and inverse gated decoupling should be carried out, to prevent the transfer of XH NOE to the BC nuclei. 

FIGURE 4.4 (a) Inversion recovery pulse sequence with inverse gated proton decoupling for 7, measurement. 

FIGURE 4.7 Inverse gated proton decoupling pulse sequence. Rd is relaxation delay, 0 is a variable pulse angle, t2 is the acquisition time. 

Figure 1.11. NMR analysis of the keto-enol tautomerism of 2,4-pentanedione [CDCI3, 50% v/v, 25 °C, 60 MHz for H, 20 MHz for 13C]. (a) 1H NMR spectrum with integrals [result keto enol = 13 87] (b) 1H broadband de-coupled 13C nMR spectrum (c) "(J NMR spectrum obtained by inverse gated h decoupling with integrals [result keto enol = 15 85 ( 1)]...

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