INEPT method

Insensitive Nuclei Enhanced by Polarization Transfer (INEPT) method (see Table 3.13). 

A P- Al J-coupling constant for trimethylphosphine bound to the Lewis acid of Zeolite HY has been determined by Al to P INEPT methods,since coupling could not be resolved for this resonance (6= —49) in the P MAS NMR spectrum. The coupling was consistent with a five-coordinated aluminium Lewis acid/trimethyl phosphine complex, and thus a four-coordinated Lewis acid site. Bi- and tricyclic penta- and hexacoordinated-phosphoranes 25-28 have been... 

Fig. 7.2.31 Filters for homonuclear coherent magnetization transfer. All filters start from and end with longitudinal magnetization, (a) Selective excitation and reconversion of coherences with a nonselective mixing period, (b) Realization of a nonselective mixing period in a z filter via longitudinal magnetization, (c) Nonselective excitation and reconversion of coherences with a selective mixing period, (d) Realization of a selective mixing period by a multi-quantum filter, (e) Selective exchange of transverse magnetization within the multiplets of coupled homonuclear spin pairs by a homonuclear version of the INEPT method.

A number of "X, ""Y coherence transfer experiments involving polarization transfer from or to quadrupolar nuclei were performed by using both INEPT and the universal polarization transfer (UPT) scheme (Fig. 1(a)) which is a generalization of DEPT. The use of the INEPT method is unproblematic. It can be applied without modification for polarization transfer from any number of equivalent spin-half nuclei to a nucleus of arbitrary spin, and a report on successful measurement of C, D INEPT spectra also demonstrated its utilization for magnetization transfer from a quadrupolar to a spin-half nucleus. Application of the UPT scheme requires appropriate adjustment of the variable pulses <(> and 9 to the spin and number of the... 

Application of the INEPT Method to °C NMR Spectral Assignments in Low-Density Polyethylene and Ethylene-Propylene Copolymer... 

Carbon 13 NMR spectra of low density-polyethylene and ethylene propylene copolymer were observed at a freqeuncy of 125.77 MHz. The INEPT method was applied to identify methyl, methylene, and methine carbons. 

It was demonstrated that the INEPT method provides a very useful technique for characterization of polymers. 

In contrast to the SPI sequence, the INEPT method (insensitive nuclei enhanced by polarisation transfer) (M 38) (M 39) is capable of inverting simultaneously more than one proton transition. Consider a two spin... 

Four yegs ago, Morris and Freeman(31) reported a method for enhancing C NMR signals by using polarization transfer from protons(INEPT). Subsequently, Doddrell and Pegg(32) showed that this INEPT method could be used to identify methine, methylene, and methyl groups of a complex molecule v en combined with appropriate delay time (A) prior to data acquisition and broad- d decou ing. If A=1/2J (J is the coupling constant between C and ), only methine carbon resonances appear in the... 

In the case of some complex compounds like tubingensin A and B (20 and 21) the more precise INEPT method has been utilised (779, 120). 

The INEPT method has already proved of value for sensitivity enhancement in N H studies, and in the study of nuclei such as Fe and coupled to It may also be exploited in studies because a suitable choice of t can invert... 

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