Probing Frontier Orbital Energies of {Co 9 (P 2 W 15 ) 3 } Polyoxometalate Clusters at Molecule–Metal and Molecule–Water Interfaces

Xiaofeng Yi , Natalya V. Izarova , Maria Stuckart , David Guérin (1) , Louis Thomas , Stéphane Lenfant (2) , Dominique Vuillaume (2, 3) , Jan van Leusen (4) , Tomas Duchon , Slavomir Nemsak , Svenja D. M. Bourone , Sebastian Schmitz (5) , Paul Kögerler (4)

1 CTP
2 IEMN - Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520
3 NCM - IEMN - Nanostructures, nanoComponents & Molecules - IEMN
4 IAC RWTH - Institute of Inorganic Chemistry [Aachen]
5 FIR e.V. an der RWTH Aachen - Institute for Industrial Management [RWTH Aachen University]

Functionalization of polyoxotungstates with organoarsonate co-ligands enabling surface decoration was explored for the triangular cluster architectures of the composition [CoII9(H2O)6(OH)3(p-RC6H4AsVO3)2({\alpha}-PV2WVI15O56)3]25-({Co9(P2W15)3}, R = H or NH2), isolated as Na25[Co9(OH)3(H2O)6(C6H5AsO3)2(P2W15O56)3]86H2O (Na-1) and Na25[Co9(OH)3(H2O)6(H2NC6H4AsO3)2(P2W15O56)3]86H2O (Na-2). The axially oriented para-aminophenyl groups in 2 facilitate the formation of self-assembled monolayers on gold surfaces, and thus provide a viable molecular platform for charge transport studies of magnetically functionalized polyoxometalates. The title systems were isolated and characterized in the solid state and in aqueous solutions, and on metal surfaces. Using conducting tip atomic force microscopy (C-AFM), the energies of {Co9(P2W15)3} frontier molecular orbitals in the surface-bound state were found to directly correlate with cyclic voltammetry data in aqueous solution.

Domaines: Physique [physics]; Matière Condensée [cond-mat]

Xiaofeng Yi, Natalya V. Izarova, Maria Stuckart, David Guérin, Louis Thomas, et al.. Probing Frontier Orbital Energies of {Co 9 (P 2 W 15 ) 3 } Polyoxometalate Clusters at Molecule–Metal and Molecule–Water Interfaces. Journal of the American Chemical Society, 2017, 139 (41), pp.14501-14510. ⟨10.1021/jacs.7b07034⟩. ⟨hal-02133798⟩