Comparison of the Effects of Different 19F π Pulses on the Sensitivity and Phaseability of the 19F-13C HSQC
- Авторы: Marchione A.1, Conklin B.1
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Учреждения:
- Chemours Fluoroproducts Analytical
- Выпуск: Том 48, № 5 (2017)
- Страницы: 485-499
- Раздел: Original Paper
- URL: https://journals.rcsi.science/0937-9347/article/view/247695
- DOI: https://doi.org/10.1007/s00723-017-0876-y
- ID: 247695
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Аннотация
The 19F-13C heteronuclear single quantum coherence (HSQC) experiment is vital for the structural elucidation of polyfluorinated organic species, yet its sensitivity and phaseability are limited by difficulties in uniform excitation of the widely disperse 19F spectral window. Adiabatic pulses of different types have previously been employed to generate effective π pulses for inversion and refocussing, but a systematic comparison of various adiabatic and other inversion pulses has not been published. In this work, it was observed that the use of a broadband inversion pulse (BIP) during the t1 evolution period resulted in properly phaseable spectra for experiments optimized to detect 1JCF, in contrast to CHIRP or WURST adiabatic pulses. For the INEPT and reverse-INEPT transfer segments of the HSQC, optimal sensitivity for resonances distant from the transmitter frequency was afforded by optimized universal rotation (BURBOP) or CHIRP pulses. In HSQC experiments with delays optimized for two-bond correlations, only the use of BURBOP pulses in INEPT and reverse-INEPT sequences afforded spectra cleanly phaseable across the F2 and F1 spectral windows. This observation is supported by off-resonance pulsed field gradient spin-echo experiments.
Об авторах
Alexander Marchione
Chemours Fluoroproducts Analytical
Автор, ответственный за переписку.
Email: alexander.marchione@chemours.com
США, Wilmington, DE
Breanna Conklin
Chemours Fluoroproducts Analytical
Email: alexander.marchione@chemours.com
США, Wilmington, DE