@article{Sinclair2026, 
author = {Zoë L. Sinclair and Vishal Lakhanpal and De-Liang Long and Nicola L. Bell and Leroy Cronin},
title = {Expanding polyoxopalladate diversity: Ce4+-containing structures and chiral lanthanide clusters},
year = {2026},
journal = {Polyoxometalates},
volume = {5},
number = {3},
pages = {9140137},
keywords = {palladium, lanthanide, polyoxopalladate, selenite, Ce4+ oxidation state, chiral cluster},
url = {https://www.sciopen.com/article/10.26599/POM.2026.9140137},
doi = {10.26599/POM.2026.9140137},
abstract = {The incorporation of lanthanides into polyoxometalates (POMs) is a fascinating area of research due to their unique chemical and physical properties, as well as their potential applications. Polyoxopalladate (POP) clusters feature flexible central cavities and coordination geometries dictated by their central metal ion templates and external capping groups. Two primary structure types have been reported: {Pd12} cubes and {Pd15} stars, which can accommodate various central metal ions, ranging from common transition metals in the +2 oxidation state to less conventional lanthanides in the +3 oxidation state. This work explores POP clusters containing cerium ions, leading to the discovery of two new structure types: [CePd13O9(SeO3)9(H2O)]6− (1) and [Ce3Pd22O16(SeO3)16]8− (2). Cluster 1 adopts a fused “star-cube” structure, combining half {Pd15} star and half {Pd12} cube with Ce4+ as the central template. 2 exhibits a twisted dumbbell-shaped structure (D2d symmetry), where two Ce4+-centred {CePd11} cubes are bridged by a third Ce4+ ion at the cluster core. Parallel experiments with other lanthanides yielded two propeller-like chiral POPs [LnPd12O7(SeO3)8Cl(H2O)2]4− (Ln = Eu3+ (3); Ln = Gd3+ (4)), both displaying C3 symmetry. Notably, this represents one of the rare instances in POP chemistry where a capping ligand (SeO32−) directly coordinates to the central lanthanide ions (Eu3+ and Gd3+). The twisted coordination of this capping ligand induces a uniform tilt in a set of {PdO4} planes, resulting in the clusters’ propeller-like chirality. In contrast, similar reaction conditions for Tb3+ produced [TbPd12O8(SeO3)8]5− (5), a normal cubic structure.}
}