Phase sensitive HMQC(Heteronuclear Multiple Quantum Coherence) and HSQC(Heteronuclear Single Quantum Coherence) experiments with t 1 noise reduction are proposed for the accurate measurement of heteronuclear one bond ...Phase sensitive HMQC(Heteronuclear Multiple Quantum Coherence) and HSQC(Heteronuclear Single Quantum Coherence) experiments with t 1 noise reduction are proposed for the accurate measurement of heteronuclear one bond 13 C 1H coupling constants. The resulting 2D spectra give anti phase splittings of heteronuclear one bond couplings along ω 2 dimension, so that the precision of coupling constant measurement is less subject to the residual t 1 noise. By combining use of data fitting procedure on a spectrum with enough digital resolution and signal to noise ratio, a precision of about 0 03 Hz can be achieved in the measurement of heteronuclear one bond coupling constants. The proposed method can be very useful for the study of residual dipolar couplings caused by the alignment in high magnetic field and the dynamic frequency shift caused by the cross correlation between chemical shift and spin dipolar interactions.展开更多
文摘Phase sensitive HMQC(Heteronuclear Multiple Quantum Coherence) and HSQC(Heteronuclear Single Quantum Coherence) experiments with t 1 noise reduction are proposed for the accurate measurement of heteronuclear one bond 13 C 1H coupling constants. The resulting 2D spectra give anti phase splittings of heteronuclear one bond couplings along ω 2 dimension, so that the precision of coupling constant measurement is less subject to the residual t 1 noise. By combining use of data fitting procedure on a spectrum with enough digital resolution and signal to noise ratio, a precision of about 0 03 Hz can be achieved in the measurement of heteronuclear one bond coupling constants. The proposed method can be very useful for the study of residual dipolar couplings caused by the alignment in high magnetic field and the dynamic frequency shift caused by the cross correlation between chemical shift and spin dipolar interactions.
