spinning frequencies. The theory of Suter and Ernst, developed for spectral spin diffusion in single crystals, was extended to the case of polycrystalline samples rotating under magic-angle spinning conditions. We considered two mechanisms for the spin diffusion, i.e. dipolar interaction and J-coupling. The spin-diffusion time constants, TSD, were related to the zero-quantum lineshape functions in a
在光谱自旋扩散13双C NMR 13 C标记的
乙酸钠三
水合物(
SAC),并在31
锌(的P NMR II)双(ø,ö '-diethyldithiophosphate)(ZNP)已根据魔角自旋研究条件。自旋扩散时间常数,T
SD通过在几个不同的纺丝频率下使用旋转同步的
DANTE脉冲序列在实验中从纺丝边带的强度确定。为在单晶中进行光谱自旋扩散而开发的Suter和Ernst理论扩展到了在魔角旋转条件下旋转的多晶样品的情况。我们考虑了自旋扩散的两种机制,即偶极相互作用和J耦合。自旋扩散时间常数,T
SD与零量子线形函数相关,其方式类似于Suter和Ernst的理论。从观察到的单量子线形函数估计零量子线形函数。在本研究中,T
SD的实验值对旋转频率v r的依赖性与基于偶极相互作用机理的理论计算得出的结果相吻合。的值Ť
SD为
SAC显示在Δ深最小ω听,说:2 ω - [R ,和最小Δ处的浅ω听,说:3