2D INEPT

Kuroda and coworkers240 used a 2D INEPT-INADEQUATE sequence with a sym-metrization similar to the simple INADEQUATE used by Hengge and Schrank218 as mentioned above. Their pulse sequence... 

Figure 11 Contour plot (adapted with permission from Ref. [38]) of the 2D 30.4 MHz N/ H HETCOR of tris(trimethylstannyl)amine, e3Sn>3N (25 °C 50% in C D basic 2D INEPT-based heteronuclear shift correlation). The drawn line in the formula shows the path of polarization transfer and the broken line connects those spins for which the sign of reduced coupling constants are compared. Four crosspeaks are visible corresponding to satellites. The positive tilt of those satellites corresponding to...

Key Words Quantitative 2D NMR, 2D -resolved NMR, COSY, TOCSY, HSQC, 2D INEPT, Natural products, Metabolomics, Oil fractions. Food analysis. 

Homonuclear coupling evolution during the pulse sequence gives its own effect to the polarization transfer to the desired coherence and therefore affects the quantitativity. For 2D INEPT the crucial point in this respect is the INEPT period. 

The loss of polarization is less severe in 2D INEPT compared to HSQC (cf. Figure 3). As Jhh seldom exceeds 10% of the /ch/ the effect of homonuclear coupling evolution to the quantitativity can be regarded as negligible in this particular case, but the error from this source should be understood when high precision in quantification is needed. 

D CC(CO)NH TOCSY-based 2D INEPT-based 2D HSQC-based... 

D HNCO and HN(CO)CA-based 2D HBHA(CBCACO)NH-based 2D INEPT-based... 

The substitution pattern is recognizable by the Si-2D-INEPT-INADEQUATE-NMR spectra (Fig. 3). 

FIGURE 3. 53.7-MHz Si- Si 2D-INEPT-INADEQUATE spectrum (a) Tetracycle 5a in CeDe-(b) Tricycle 6 in CDCI3 (40 °C). and projection of the 2D spectrum on the F2 axis (top). Signals connected by solid lines correspond to one-bond interactions ( /) those connected by dotted lines denote long-range couplings ("/). Reproduced by permission of VCH Verlagsgesellschaft from Reference 12... 

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