Combination of cross polarization/magic angle spinning NMR and x-ray crystallography: structure and dynamics in a low-symmetry molecular crystal, potassium penicillin V
Combination of cross polarization/magic angle spinning NMR and x-ray crystallography: structure and dynamics in a low-symmetry molecular crystal, potassium penicillin V
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交叉偏振/魔角旋转 NMR 和 X 射线晶体学的组合：低对称性分子晶体青霉素 V 钾的结构和动力学
DOI：
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发表时间：
1993
期刊：
影响因子：
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通讯作者：
C. Dobson
中科院分区：
文献类型：
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作者：
Jamila Fattah;J. M. Twyman;S. J. Heyes;D. Watkin;A. Edwards;K. Prout;C. Dobson
青霉素V钾盐（C16 H17 N2 O 5SK）在T<352 K时的变温13 C CP/MAS NMR谱表明，其晶体不对称单元中含有4个分子，具有不寻常的低对称结构。这是证实了单晶X-射线衍射研究，其中采用了一种新的计算协议，以允许解决方案的结构，这表明，四个不同的分子主要不同的苯氧基侧链相对于penam单元的取向。包装图案揭示了与晶胞某些部分相关的不同的伪对称元素，这可能解释了这种不常见的复杂结构的发生
The variable-temperature 13 C CP/MAS NMR spectra of the potassium salt of phenoxymethylpenicillin (C 16 H 17 N 2 O 5 SK) (potassium penicillin V) at T<352 K indicate an unusual low-symmetry structure with four molecules in the crystallographic asymmetric unit. This is confirmed by a single-crystal X-ray diffraction study, which employed a novel computational protocol to allow solution of the structure, which indicates that the four distinct molecules differ principally in the orientation of the phenoxy side chain with respect to the penam unit. The packing motif reveals different pseudosymmetry elements relating certain parts of the unit cell, which may explain the occurrence of this uncommon complex structure