@article{Zhang2025, 
author = {Jiayao Zhang and Saurav Bhattacharya and Mahmoud Elcheikh Mahmoud and Talha Nisar and Khaoula Merimi and Xavier López and Josep M. Poblet and Veit Wagner and Ulrich Kortz},
title = {Platinum-containing isopolytungstates: [Pt3W11O41]6.4− with a linear {Pt3O12} triad, [PtII2W5O18((CH3)2AsO2)2]4− and [PtIII2W5O18((CH3)2AsO2)4]4− featuring direct Pt–Pt bonds},
year = {2025},
journal = {Polyoxometalates},
volume = {4},
number = {4},
pages = {9140107},
keywords = {platinum, polyoxometalates, Pt–Pt bond, hydrogenation catalysis, mixed-valence compounds, quantum mechanical calculations},
url = {https://www.sciopen.com/article/10.26599/POM.2025.9140107},
doi = {10.26599/POM.2025.9140107},
abstract = {The platinum-containing isopolytungstates [Pt3W11O41]6.4− (Pt3W11), [PtII2W5O18((CH3)2AsO2)2]4− (PtII2W5), and [PtIII2W5O18((CH3)2AsO2)4]4− (PtIII2W5) were synthesized in aqueous media and characterized via single-crystal X-ray diffraction and multinuclear (195Pt, 13C, and 1H) nuclear magnetic resonance (NMR) spectroscopy. The polyanion [Pt3W11O41]6.4− comprises three {W3O13} and one {W2O10} fragments connected via three platinum atoms forming a linear {Pt3O12} triad that exhibit direct Pt–Pt bonding (2.64–2.68 Å). The distances between the two outer Pt ions and oxygens from neighboring Pt3W11  clusters (2.34 and 2.65 Å) are consistent with [4+1] coordination. Quantum mechanical calculations enabled the assignment of Pt oxidation states for the mixed-valence polyanion Pt3W11. The polyanion PtII2W5 contains a monolacunary {W5O18}6− Lindqvist fragment coordinated via two PtII ions in square-planar geometry and two terminal dimethylarsinate groups, exhibiting a 195Pt NMR signal at 610 ppm in water. By contrast, PtIII2W5 comprises two PtIII ions with square-pyramidal coordination and direct Pt–Pt bonding (2.64 Å). The polyanions Pt3W11 and PtII2W5 were immobilized on SBA-15-apts and then tested as precatalysts for the hydrogenation of o-xylene under continuous-flow, high-pressure conditions.}
}