Strandberg E, Westlund P
Department of Chemistry, Biophysical Chemistry, Umeå University, Umeå, 901 87, Sweden.
J Magn Reson. 1999 Apr;137(2):333-44. doi: 10.1006/jmre.1998.1696.
A generalization of the modified Solomon-Bloembergen-Morgan (MSBM) equations has been derived in order to describe paramagnetic relaxation enhancement (PRE) of paramagnetic complexes characterized by both a transient (DeltaZFSt) and a static (DeltaZFSs) zero-field splitting (ZFS) interaction. The new theory includes the effects of static ZFS, hyperfine coupling, and angular dependence and is presented for the case of electron spin quantum number S = 52, for example, Mn(II) and Fe(III) complexes. The model gives the difference from MSBM theory in terms of a correction term delta which is given in closed analytical form. The theory may be important in analyzing the PRE of proton spin-lattice relaxation dispersion measurements (NMRD profiles) of low-symmetry aqua-metal complexes which are likely to be formed upon transition metal ions associated with charged molecular surfaces of biomacromolecules. The theory has been implemented with a computer program which calculates solvent water proton T1 NMRD profiles using both MSBM and the new theory.
为了描述具有瞬态（ΔZFSt）和静态（ΔZFSs）零场分裂（ZFS）相互作用特征的顺磁性配合物的顺磁弛豫增强（PRE），已推导了修正的所罗门 - 布洛姆贝根 - 摩根（MSBM）方程的推广形式。新理论包括静态ZFS、超精细耦合和角度依赖性的影响，并且针对电子自旋量子数S = 5/2的情况进行了阐述，例如Mn（II）和Fe（III）配合物。该模型以封闭解析形式给出的校正项δ表示与MSBM理论的差异。该理论对于分析低对称性水合金属配合物的质子自旋 - 晶格弛豫色散测量（NMRD谱）的PRE可能很重要，这些配合物可能在与生物大分子带电分子表面相关的过渡金属离子作用下形成。该理论已通过一个计算机程序实现，该程序使用MSBM和新理论计算溶剂水质子T1 NMRD谱。
