Fast Magic-Angle Spinning Three-Dimensional NMR Experiment for Simultaneously Probing H—H and N—H Proximities in Solids

W2542572066 · 수집 2026-10-04 18:12:28

T11878 Solid-state spectroscopy and crystallography

CoT 라벨링

라벨링 전

PDF 파일

저장된 PDF 없음

기본 정보

DOI 제목 발행년도 저널 URL 페이지 열기 PDF URL 발행기관 피인용수 라이선스

추가 정보 초록

A fast magic-angle spinning (MAS, 70 kHz) solid-state NMR experiment is presented that combines 1H Double-Quantum (DQ) and 14N—1H HMQC (Heteronuclear Multiple-Quantum Coherence) pulse-sequence elements, so as to simultaneously probe H—H and N—H proximities in molecular solids. The proposed experiment can be employed in both two-dimensional (2D) and three-dimensional (3D) versions: first, a 2D 14N HMQC-filtered 1H-DQ experiment provides specific DQ-SQ correlation peaks for proton pairs that are in close proximities to the nitrogen sites, thereby achieving spectral filtration. Second, a proton-detected three-dimensional (3D) 1H(DQ)-14N(SQ)-1H(SQ) experiment correlates 1H(DQ)-1H(SQ) chemical shifts with 14N shifts such that longer range N···H—H correlations are observed between protons and nitrogen atoms with internuclear NH distances exceeding 3 Å. Both 2D and 3D versions of the proposed experiment are demonstrated for an amino acid hydrochloride salt, l-histidine·HCl·H2O, and a DNA nucleoside, guanosine·2H2O. In the latter case, the achieved spectral filtration ensures that DQ cross peaks are only observed for guanine NH and CH8 1H resonances and not ribose and water 1H resonances, thus providing insight into the changes in the solid-state structure of this hydrate that occur over time; significant changes are observed in the NH and NH2 1H chemical shifts as compared to the freshly recrystallized sample previously studied by Reddy et al., Cryst. Growth Des. 2015, 15, 5945.

본문 활용가능성

이력 0건

아직 편집 이력이 없습니다. 저장할 때마다 이전 내용이 여기에 백업됩니다.