Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Complete H-1 resonance assignment of beta-maltose from H-1-H-1 DQ-SQ CRAMPS and H-1 (DQ-DUMBO)-C-13 SQ refocused INEPT 2D solid-state NMR spectra and first principles GIPAW calculations
AU - Webber, Amy L.
AU - Elena, Benedicte
AU - Griffin, John M.
AU - Yates, Jonathan R.
AU - Pham, Tran N.
AU - Mauri, Francesco
AU - Pickard, Chris J.
AU - Gil, Ana M.
AU - Stein, Robin
AU - Lesage, Anne
AU - Emsley, Lyndon
AU - Brown, Steven P.
PY - 2010
Y1 - 2010
N2 - A disaccharide is a challenging case for high-resolution H-1 solid-state NMR because of the 24 distinct protons (14 aliphatic and 10 OH) having H-1 chemical shifts that all fall within a narrow range of approximately 3 to 7 ppm. High-resolution H-1 (500 MHz) double-quantum (DQ) combined rotation and multiple pulse sequence (CRAMPS) solid-state NMR spectra of beta-maltose monohydrate are presented. H-1-H-1 DQ-SQ CRAMPS spectra are presented together with H-1 (DQ)-C-13 correlation spectra obtained with a new pulse sequence that correlates a high-resolution H-1 DQ dimension with a C-13 single quantum (SQ) dimension using the refocused INEPT pulse-sequence element to transfer magnetization via one-bond C-13-H-1 J couplings. Compared to the observation of only a single broad peak in a H-1 DQ spectrum recorded at 30 kHz magic-angle spinning (MAS), the use of DUMBO H-1 homonuclear decoupling in the H-1 DQ CRAMPS experiment allows the resolution of distinct DQ correlation peaks which, in combination with first-principles chemical shift calculations based on the GIPAW (Gauge Including Projector Augmented Waves) plane-wave pseudopotential approach, enables the assignment of the H-1 resonances to the 24 distinct protons. We believe this to be the first experimental solid-state NMR determination of the hydroxyl OH H-1 chemical shifts for a simple sugar. Variable-temperature H-1-H-1 DQ CRAMPS spectra reveal small increases in the H-1 chemical shifts of the OH resonances upon decreasing the temperature from 348 K to 248 K.
AB - A disaccharide is a challenging case for high-resolution H-1 solid-state NMR because of the 24 distinct protons (14 aliphatic and 10 OH) having H-1 chemical shifts that all fall within a narrow range of approximately 3 to 7 ppm. High-resolution H-1 (500 MHz) double-quantum (DQ) combined rotation and multiple pulse sequence (CRAMPS) solid-state NMR spectra of beta-maltose monohydrate are presented. H-1-H-1 DQ-SQ CRAMPS spectra are presented together with H-1 (DQ)-C-13 correlation spectra obtained with a new pulse sequence that correlates a high-resolution H-1 DQ dimension with a C-13 single quantum (SQ) dimension using the refocused INEPT pulse-sequence element to transfer magnetization via one-bond C-13-H-1 J couplings. Compared to the observation of only a single broad peak in a H-1 DQ spectrum recorded at 30 kHz magic-angle spinning (MAS), the use of DUMBO H-1 homonuclear decoupling in the H-1 DQ CRAMPS experiment allows the resolution of distinct DQ correlation peaks which, in combination with first-principles chemical shift calculations based on the GIPAW (Gauge Including Projector Augmented Waves) plane-wave pseudopotential approach, enables the assignment of the H-1 resonances to the 24 distinct protons. We believe this to be the first experimental solid-state NMR determination of the hydroxyl OH H-1 chemical shifts for a simple sugar. Variable-temperature H-1-H-1 DQ CRAMPS spectra reveal small increases in the H-1 chemical shifts of the OH resonances upon decreasing the temperature from 348 K to 248 K.
KW - POWDER DIFFRACTION DATA
KW - QUANTUM-CHEMICAL CALCULATIONS
KW - NUCLEAR-MAGNETIC-RESONANCE
KW - PROTON-PROTON PROXIMITIES
KW - DENSITY-FUNCTIONAL THEORY
KW - PI-PI PACKING
KW - CRYSTAL-STRUCTURE
KW - O-17 NMR
KW - 1ST-PRINCIPLES CALCULATION
KW - CORRELATION SPECTROSCOPY
U2 - 10.1039/c001290d
DO - 10.1039/c001290d
M3 - Journal article
VL - 12
SP - 6970
EP - 6983
JO - Physical Chemistry Chemical Physics
JF - Physical Chemistry Chemical Physics
SN - 1463-9076
IS - 26
ER -