Impact of Solvent Polarity on the Ligand Configuration in Tetravalent Thorium N-Donor Complexes
作者:Thomas Sittel、Michael Trumm、Christian Adam、Andreas Geist、Petra J. Panak
DOI:10.1021/acs.inorgchem.0c03213
日期:2021.1.18
A combined NMR spectroscopic and theoretical study on the complexation of diamagnetic Th(IV) with 2,6-bis(5,6-dipropyl-1,2,4-triazin-3-yl)pyridine (nPr-BTP) was performed. Different ligand configurations were observed for [Th(nPr-BTP)3]4+ complexes depending on the solvent’s ability to actively form hydrogen bonds. In polar aprotic solvents, a complex is observed, which is isostructural with [M(nPr-BTP)3]3+
结合NMR光谱和理论研究了抗磁性Th(IV)与2,6-双(5,6-二丙基-1,2,4-三嗪-3-基)吡啶(n Pr-BTP)的络合。对于[Th(n Pr-BTP)3 ] 4+配合物,观察到不同的配体构型,具体取决于溶剂主动形成氢键的能力。在极性非质子溶剂中,观察到一种络合物,该络合物与先前研究的[M(n Pr-BTP)3 ] 3+(M = Am,Ln)络合物是同构的。相反,1 H,13 C和15极性质子溶剂中记录的N NMR谱图显示两倍的信号,表明对称性破裂。在密度泛函理论(DFT)计算的支持下,这种差异可以通过溶剂对位于三嗪环上的丙基部分的空间排列的影响来解释。关于结合性能的重要信息通过15 N NMR获得。与各自的Am(III)络合物显示出显着的共价贡献相反,Th(IV)-BTP相互作用主要是静电的。