Remenyi Christian, Munzarova Markéta L, Kaupp Martin
Institut für Anorganische Chemie, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany.
J Phys Chem B. 2005 Mar 10;109(9):4227-33. doi: 10.1021/jp045148+.
Electronic g tensors and hyperfine coupling tensors have been calculated for amavadin, an unusual eight-coordinate vanadium(IV) complex isolated from Amanita muscaria mushrooms. Different density-functional methods have been compared, ranging from local via gradient-corrected to hybrid functionals with a variable Hartree-Fock exchange admixture. For both electron paramagnetic resonance (EPR) properties, hybrid functionals with an appreciable exact-exchange admixture provide the closest agreement with experimental data. Second-order spin-orbit corrections provide non-negligible contributions to the 51V hyperfine tensor. The orientation of g and A tensors relative to each other also depends on spin-orbit corrections to the A tensor. A rationalization for the close resemblance of the EPR parameters of amavadin to those of the structurally rather different vanadyl complexes is provided, based on the nature of the relevant frontier orbitals.
已对从毒蝇伞蘑菇中分离出的一种不同寻常的八配位钒（IV）配合物——阿玛瓦丁的电子g张量和超精细耦合张量进行了计算。比较了不同的密度泛函方法，范围从局域泛函到梯度校正泛函，再到具有可变哈特里-福克交换混合比的杂化泛函。对于这两种电子顺磁共振（EPR）性质，具有可观精确交换混合比的杂化泛函与实验数据最为吻合。二阶自旋-轨道校正对51V超精细张量有不可忽略的贡献。g张量和A张量彼此之间的取向也取决于对A张量的自旋-轨道校正。基于相关前沿轨道的性质，对阿玛瓦丁的EPR参数与结构上差异较大的钒氧基配合物的EPR参数非常相似的现象给出了一种合理解释。
