Galley Shane S, Pattenaude Scott A, Ray Debmalya, Gaggioli Carlo Alberto, Whitefoot Megan A, Qiao Yusen, Higgins Robert F, Nelson W L, Baumbach Ryan, Sperling Joseph M, Zeller Matthias, Collins Tyler S, Schelter Eric J, Gagliardi Laura, Albrecht-Schönzart Thomas E, Bart Suzanne C
H. C. Brown Laboratory, Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States.
Department of Chemistry, Supercomputing Institute, and Chemical Theory Centre, University of Minnesota, Minneapolis, Minnesota 55455, United States.
Inorg Chem. 2021 Oct 18;60(20):15242-15252. doi: 10.1021/acs.inorgchem.1c01766. Epub 2021 Sep 27.
Using a redox-active dioxophenoxazine ligand, DOPO (DOPO = 2,4,6,8-tetra--butyl-1-oxo-1-phenoxazine-9-olate), a family of actinide (U, Th, Np, and Pu) and Hf tris(ligand) coordination compounds was synthesized. The full characterization of these species using H NMR spectroscopy, electronic absorption spectroscopy, SQUID magnetometry, and X-ray crystallography showed that these compounds are analogous and exist in the form M(DOPO)(DOPO), where two ligands are of the oxidized quinone form (DOPO) and the third is of the reduced semiquinone (DOPO) form. The electronic structures of these complexes were further investigated using CASSCF calculations, which revealed electronic structures consistent with metals in the +4 formal oxidation state and one unpaired electron localized on one ligand in each complex. Furthermore, f orbitals of the early actinides show a sizable bonding overlap with the ligand 2p orbitals. Notably, this is the first example of a plutonium-ligand radical species and a rare example of magnetic data being recorded for a homogeneous plutonium coordination complex.
使用一种氧化还原活性的二氧杂吩恶嗪配体DOPO（DOPO = 2,4,6,8 - 四 - 叔丁基 - 1 - 氧代 - 1 - 吩恶嗪 - 9 - 醇盐），合成了一系列锕系元素（U、Th、Np和Pu）以及Hf的三（配体）配位化合物。通过¹H NMR光谱、电子吸收光谱、超导量子干涉仪磁力测量和X射线晶体学对这些化合物进行的全面表征表明，这些化合物具有相似性，以M(DOPO)₃形式存在，其中两个配体为氧化醌形式（DOPO²⁻），第三个为还原半醌（DOPO⁻）形式。使用完全活性空间自洽场（CASSCF）计算进一步研究了这些配合物的电子结构，结果表明其电子结构与处于 +4形式氧化态的金属以及每个配合物中一个配体上局域的一个未成对电子相一致。此外，早期锕系元素的f轨道与配体的2p轨道表现出相当大的成键重叠。值得注意的是，这是钚 - 配体自由基物种的首个实例，也是记录到均匀钚配位配合物磁数据的罕见实例。
