Characterization of polymorphs and solid-state reactions for paramagnetic systems by 13C solid-state NMR and ab initio calculations
Characterization of polymorphs and solid-state reactions for paramagnetic systems by 13C solid-state NMR and ab initio calculations
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DOI：
10.1021/ja0703980
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发表时间：
2007-09-12
影响因子：
15
通讯作者：
Ishii, Yoshitaka
中科院分区：
文献类型：
--
作者：
Shaibat, Medhat A.;Casabianca, Leah B.;Ishii, Yoshitaka
尽管其在药物和材料科学中的重要性，但顺磁系统的多晶型物或超分子结构的光谱表征通常会带来挑战，特别是对于非结晶固体。这项工作表明，C-13固态核磁共振（SSNMR）的顺磁系统在非常快的魔角旋转（VFMAS）（旋转速度为20 kHz或更高）提供了异常灵敏的手段，探测小的结构差异的多晶型物的顺磁复合物在非结晶固体，包括药物和材料含有顺磁金属离子。抗癌药物Cu（II）（B-quilinolinol）（2）的13 C VFMAS SSNMR实验和相应的从头计算位移计算表明，该化合物的α-和β-形式可以通过顺磁弛豫时间和超精细位移的显著差异而容易地区分。它还表明，本技术的应用程序允许以非侵入性方式对Cu（8-quilinolinol）（2）和Cu（咪唑）（2）的固态反应进行定量和化学表征。
Despite its importance in drug and material science, spectroscopic characterization of polymorphs or supramolecular structures of paramagnetic systems often poses challenges, particularly for noncrystalline solids. This work demonstrates that C-13 solid-state NMR (SSNMR) of paramagnetic systems under very fast magic angle spinning (VFMAS) (spinning speed of 20 kHz or higher) provides exceptionally sensitive means to probe small structural difference among polymorphs of paramagnetic complexes in noncrystalline solids, including drugs and materials containing paramagnetic metal ions. 13C VFMAS SSNMR experiments and corresponding ab initio shift calculations for Cu(II)(B-quilinolinol)(2), anticancer agents, show that alpha- and beta-forms of this compound can be easily distinguished by notable difference in paramagnetic relaxation times and hyperfine shifts. It is also shown that applications of the present technique allow for quantitative and chemical characterization of solid-state reactions for Cu(8-quilinolinol)(2) and Cu (imidazole)(2) in a noninvasive manner.