Orr Robin M, Duer Melinda J
Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
J Magn Reson. 2006 Jul;181(1):1-8. doi: 10.1016/j.jmr.2006.03.010. Epub 2006 Mar 30.
A comparison of three different implementations of the chemical-shift recoupling experiment of Tycko et al. [R. Tycko, G. Dabbagh, P.A. Mirau, Determination of chemical-shift-anisotropy lineshapes in a two-dimensional magic-angle-spinning NMR experiment, J. Magn. Reson. 85 (1989) 265-274] is presented. The methods seek to reduce the effects of artefacts resulting from pulse imperfections and residual C-H dipolar coupling in organic solids. An optimised and constant time implementation are shown to give well-defined and artefact free powder pattern lineshapes in the indirectly observed dimension for both sp2 and sp3 carbon sites. Experimental setup is no more demanding than for the original experiment, and can be implemented using standard commercial hardware.
本文对泰科等人[R. 泰科、G. 达巴格、P.A. 米拉乌，《二维魔角旋转核磁共振实验中化学位移各向异性线形的测定》，《磁共振杂志》85 (1989) 265 - 274]的化学位移重耦合实验的三种不同实现方式进行了比较。这些方法旨在减少有机固体中由于脉冲缺陷和残余C - H偶极耦合导致的伪影的影响。对于sp2和sp3碳位点，优化的恒时实现方式在间接观测维度上能给出定义明确且无伪影的粉末图样线形。实验设置并不比原实验要求更高，并且可以使用标准的商业硬件来实现。
