An R1ρ expression for a spin in chemical exchange between two sites with unequal transverse relaxation rates
An R1ρ expression for a spin in chemical exchange between two sites with unequal transverse relaxation rates
复制标题
DOI：
10.1007/s10858-012-9694-6
复制
发表时间：
2013-02-01
影响因子：
2.7
通讯作者：
Kay, Lewis E.
中科院分区：
文献类型：
--
作者：
Baldwin, Andrew J.;Kay, Lewis E.
本文导出了两个不同横向弛豫时间的自旋交换的旋转坐标系弛豫速率R（1 ρ）的解析表达式。一些限制的情况下进行检查，与方程减少到公式推导出的假设下，在每个站点的等效松弛率。测量一对非共振R（1 rho）值，其中载流子在所观察到的相关性的两侧相等地位移，形成了获得交换核的化学位移差异Delta omega迹象的方法之一的基础。这里给出的结果表明，这种方法是相对不敏感的差分横向弛豫率之间的交换状态，大大简化了计算的最佳参数在R（1 ρ）为基础的实验，用于测量的符号的Δ Ω。
An analytical expression is derived for the rotating frame relaxation rate, R (1 rho) , of a spin exchanging between two sites with different transverse relaxation times. A number of limiting cases are examined, with the equation reducing to formulae derived previously under the assumption of equivalent relaxation rates at each site. The measurement of a pair off-resonance R (1 rho) values, with the carrier displaced equally on either side of the observed correlation, forms the basis of one of the approaches for obtaining signs of chemical shift differences, Delta omega, of exchanging nuclei. The results presented here establish that this method is relatively insensitive to differential transverse relaxation rates between the exchaning states, greatly simplifying the calculation of optimal parameters in R (1 rho) based experiments that are used for measurement of signs of Delta omega.