Improved double-quantum NMR correlation spectroscopy of dipolar-coupled quadrupolar spins
Improved double-quantum NMR correlation spectroscopy of dipolar-coupled quadrupolar spins
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DOI：
10.1016/j.cplett.2006.09.081
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发表时间：
2006-11-24
影响因子：
2.8
通讯作者：
Yu, Jihong
中科院分区：
文献类型：
--
作者：
Eden, Mattias;Zhou, Dan;Yu, Jihong
我们表明，基于量子力学的零量子偶极再耦合序列夹在中心跃迁选择性π/2脉冲之间，可以用来激发双量子相干（2 QC）的中心跃迁的homopoly半整数四极自旋进行魔角自旋。用Na ~（23）和Al ~（27）NMR对Na_2SO_3和α-Al_2O_3模型化合物的2 QC激发进行了实验研究。当结合到2 Q-1 Q二维相关协议中时，新的再耦合方法在开放骨架铝磷酸盐AlPO-CJ 19 [（NH 4）（2）Al-4（PO 4）（4）HPO4.H2O]和层状矿物Mg 9Al 6Si 5 O20（OH）（16）]中建立了所有预期的Al-27-Al-27连接性超过6埃。(c)2006 Elsevier B. V.保留所有权利。
We show that symmetry-based zero-quantum dipolar recoupling sequences sandwiched between central transition selective pi/2-pulses may be used to excite double-quantum coherences (2QC) between the central transitions of homonuclear half-integer quadrupolar spins undergoing magic-angle spinning. The 2QC excitation is explored experimentally by Na-23 and Al-27 NMR on Na2SO3 and alpha-Al2O3 model compounds. When incorporated into 2Q-1Q 2D correlation protocols, the new recoupling method established all expected Al-27-Al-27 connectivities over 6 angstrom in the open-framework aluminophosphate AlPO-CJ19 [(NH4)(2)Al-4(PO4)(4)HPO4.H2O] and the layer mineral chlorite [Mg9Al6Si5O20(OH)(16)]. (c) 2006 Elsevier B.V. All rights reserved.