Elucidating connectivity and metal-binding structures of unlabeled paramagnetic complexes by 13C and 1H solid-state NMR under fast magic angle spinning.
Elucidating connectivity and metal-binding structures of unlabeled paramagnetic complexes by 13C and 1H solid-state NMR under fast magic angle spinning.
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在快速魔角旋转下通过 13C 和 1H 固态 NMR 阐明未标记顺磁配合物的连接性和金属结合结构。
DOI：
10.1021/jp0727289
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
Ishii,Yoshitaka
中科院分区：
文献类型：
--
作者：
Wickramasinghe,NalindaP;Shaibat,MedhatA;Ishii,Yoshitaka
表征固体中的顺磁性复合物是理解其分子功能的重要一步。然而，在分子水平上表征顺磁系统的化学和电子结构的方法受到了显着的限制，特别是对于非结晶固体。我们提出了一种通过13 C和1H高分辨率固态核磁共振（SSNMR）使用非常快魔角旋转（VFMAS，旋转速度≥20 kHz）获得未标记顺磁配合物化学基团和金属结合结构的连接性的方法。实验表明，未标记的Cu（II）（Ala-Thr），2D 13 C/H相关SSNMR下VFMAS提供的化学基团的连接性和分配在固体中的未标记的顺磁系统的表征。我们证明，在VFMAS方法提供的分配的基础上，多个13 C −金属距离可以同时阐明由13 C各向异性超精细位移和13 CT 1弛豫的测量相结合，由于超精细相互作用的肽−Cu（II）复合物。它还表明，1H各向异性超精细位移的分析允许在铁（III）-氯原卟啉-IX在固态的电子自旋状态的测定。
Characterizing paramagnetic complexes in solids is an essential step toward understanding their molecular functions. However, methodologies to characterize chemical and electronic structures of paramagnetic systems at the molecular level have been notably limited, particularly for noncrystalline solids. We present an approach to obtain connectivities of chemical groups and metal-binding structures for unlabeled paramagnetic complexes by13C and1H high-resolution solid-state NMR (SSNMR) using very fast magic angle spinning (VFMAS, spinning speed ≥20 kHz). It is experimentally shown for unlabeled Cu(II)(Ala-Thr) that 2D13C/H correlation SSNMR under VFMAS provides the connectivity of chemical groups and assignments for the characterization of unlabeled paramagnetic systems in solids. We demonstrate that on the basis of the assignments provided by the VFMAS approach multiple13C−metal distances can be simultaneously elucidated by a combination of measurements of13C anisotropic hyperfine shifts and13CT1relaxation due to hyperfine interactions for this peptide−Cu(II) complex. It is also shown that an analysis of1H anisotropic hyperfine shifts allows for the determination of electron-spin states in Fe(III)-chloroprotoporphyin-IX in solid states.