A selective INEPT experiment for the assignment of NMR lines of low-gyromagnetic ratio nuclei through long-range couplings

Abstract

A selective variant of the standard INEPT experiment is suggested. The selectivity is achieved by replacing the refocusing proton pulses of the standard INEPT pulse sequence with selective (DANTE) 180° pulses. Since this approach eliminates the undesirable influences of homo- and heteronuclear couplings, the sensitivity of the method is high. In the case of assigning 29Si NMR lines of trimethylsilylated compounds the pulse sequence can be further simplified and a pair of refocusing pulses can be eliminated from the refocusing period. Advantages of the simplified method are demonstrated.