TY - GEN A1 - Balas, Johannes A1 - Urbank, Christian A1 - Kaden, Peter A1 - Patzschke, Michael A1 - März, Juliane A1 - Kvashnina, Kristina O. A1 - Schmidt, Moritz A1 - Stumpf, Thorsten A1 - Gericke, Robert T1 - Bonding trends in pyridine-2-thiolato complexes of tetravalent actinides T2 - Inorganic chemistry N2 - Complexes of tetravalent actinides (An: Th, U, Np, Pu) with the bidentate (N,S)-donor ligand pyridine-2-thiolate (2-PyS, PyS−) were synthesized in 1:4 or 1:5 ratios. This includes the first structurally characterized Np complex with (N,S)-donor ligands, filling a notable gap in An coordination chemistry. An improved synthetic approach with PyS–SiMe3 enabled efficient formation of the 1:4 complexes in THF as coordinating solvent. The compounds were comprehensively characterized in solution and in solid phase, supported by quantum chemical calculations. Experimental and theoretical results show matching trends in the binding behavior of AnIV. The covalent bond contributions in An–N and An–S bonding increase along the series of An from Th to Pu. The bonds to the soft sulfur donors consistently have the highest covalent contributions with a remarkably high percentage for Pu–S (IQA analysis: >34%) over the harder N donors or An–O bonds of coordinating THF. High-resolution X-ray absorption and infrared spectroscopy indicate similar electronic and structural properties across AnIV complexes, while SQUID magnetometry uncovered significant differences in magnetic behavior at low temperatures depending on the complex compositions. This work advances the understanding of An-ligand bonding, emphasizing covalency and electronic structures, and expands fundamental insights into An chemistry. KW - Actinides KW - Single-crystal X-ray diffraction KW - Bonding trends KW - HERFD-XANES KW - SQUID Y1 - 2025 U6 - https://doi.org/10.1021/acs.inorgchem.5c03369 SN - 1520-510X VL - 64 IS - 44 SP - 21919 EP - 21931 PB - American Chemical Society CY - Washington, DC ER -