Kervern Gwendal, Pintacuda Guido, Zhang Yong, Oldfield Eric, Roukoss Charbel, Kuntz Emile, Herdtweck Eberhardt, Basset Jean-Marie, Cadars Sylvian, Lesage Anne, Copéret Christophe, Emsley Lyndon
Laboratoire de Chimie, UMR 5182 CNRS-ENS Lyon, Ecole Normale Supérieure de Lyon, 46 Allée d'Italie, 69364 Lyon Cedex 07, France.
J Am Chem Soc. 2006 Oct 18;128(41):13545-52. doi: 10.1021/ja063510n.
A general protocol for the structural characterization of paramagnetic molecular solids using solid-state NMR is provided and illustrated by the characterization of a high-spin Fe(II) catalyst precursor. We show how good NMR performance can be obtained on a molecular powder sample at natural abundance by using very fast (>30 kHz) magic angle spinning (MAS), even though the individual NMR resonances have highly anisotropic shifts and very short relaxation times. The results include the optimization of broadband heteronuclear (proton-carbon) recoupling sequences for polarization transfer; the observation of single or multiple quantum correlation spectra between coupled spins as a tool for removing the inhomogeneous bulk magnetic susceptibility (BMS) broadening; and the combination of NMR experiments and density functional theory calculations, to yield assignments.
本文提供了一种使用固态核磁共振对顺磁性分子固体进行结构表征的通用方案，并通过对一种高自旋Fe(II)催化剂前体的表征进行了说明。我们展示了通过使用非常快（>30 kHz）的魔角旋转（MAS），即使单个核磁共振共振具有高度各向异性的位移和非常短的弛豫时间，也能在天然丰度的分子粉末样品上获得良好的核磁共振性能。结果包括优化用于极化转移的宽带异核（质子 - 碳）重新耦合序列；观察耦合自旋之间的单量子或多量子相关光谱，作为消除非均匀体磁化率（BMS）展宽的工具；以及结合核磁共振实验和密度泛函理论计算以进行归属。
