Birnoschi Letitia, Oakley Meagan S, McInnes Eric J L, Chilton Nicholas F
Department of Chemistry, The University of Manchester Oxford Road, Manchester M13 9PL, U.K.
Research School of Chemistry, The Australian National University, Sullivans Creek Road, Canberra, Acton 2601, Australia.
J Am Chem Soc. 2024 May 29;146(21):14660-14671. doi: 10.1021/jacs.4c01930. Epub 2024 May 16.
We investigate actinide covalency effects in two [AnCp] (An = Th, U) complexes recently studied with pulsed electron paramagnetic resonance spectroscopy, using the Hyperion package to obtain relativistic hyperfine coupling constants from relativistic multiconfigurational wave functions. H and C HYSCORE simulations using the computed parameters show excellent agreement with the experimental data, highlighting the accuracy of modern relativistic ab initio methods. The extent of covalency indicated from the calculations on [ThCp] is in agreement with the original report based on traditional spectral fitting methods, while the covalency in [UCp] is found to be previously overestimated. The latter is due to the paramagnetic spin-orbit effect that arises naturally in a relativistic theory of hyperfine coupling and yet was not accounted for in the original study, thus highlighting the necessity of relativistic approaches for the interpretation of magnetic resonance data pertaining to actinides.
我们利用Hyperion软件包，从相对论多组态波函数中获取相对论超精细耦合常数，对最近通过脉冲电子顺磁共振光谱研究的两种[AnCp]（An = Th、U）配合物中的锕系元素共价效应进行了研究。使用计算参数进行的H和C HYSCORE模拟与实验数据显示出极佳的一致性，突出了现代相对论从头算方法的准确性。基于[ThCp]的计算所表明的共价程度与基于传统光谱拟合方法的原始报告一致，而[UCp]中的共价程度则被发现先前被高估了。后者是由于在相对论超精细耦合理论中自然出现的顺磁自旋轨道效应，而在原始研究中并未考虑到这一点，因此突出了相对论方法对于解释与锕系元素相关的磁共振数据的必要性。
