Syntheses, characterizations and properties of [Mo2O2S2]-based oxothiomolybdenum wheels incorporating bisphosphonate ligands.
We report the syntheses and characterizations of the first polyoxothiometalate complexes isolated from the reaction of the oxothiocationic [Mo(V)(2)O(2)S(2)](2+) precursor and bisphosphonate ligands H(2)O(3)PCR(OH)PO(3)H(2) (R = C(4)H(5)N(2), zoledronic acid; R = C(3)H(6)NH(2), alendronic acid). [(Mo(2)O(2)S(2)(H(2)O))(4)(O(3)PC(O)(C(4)H(6)N(2))PO(3))(4)](8-) (Mo(8)S(8)(Zol)(4)) and [(Mo(2)O(2)S(2)(H(2)O))(4)(O(3)PC(O)(C(3)H(6)NH(3))PO(3))(4)](8-) (Mo(8)S(8)(Ale)(4)) contain four Mo(V) dimers connected via bisphosphonate ligands. These compounds offer a unique opportunity to compare the structures and properties of cyclic compounds obtained with [Mo(2)O(2)S(2)](2+) and with [Mo(2)O(4)](2+). The oxothio compounds appear less stable in solution than the oxo analogue, confirming the higher lability and versatility of [Mo(2)O(2)S(2)]-based compounds compared to [Mo(2)O(4)]-based POMs. Multinuclear and multidimensional solid-state NMR studies were carried out to complement X-ray diffraction analysis. Information on short-range interactions, dynamic behaviors, and local disorder within the crystalline materials are therefore reported. Furthermore, the electrocatalytic properties of Mo(8)S(8)(Ale)(4) and of the analogous [(Mo(2)O(4)(H(2)O))(4)(O(3)PC(O)(C(3)H(6)NH(3))PO(3))(4)](8-) (Mo(8)O(8)(Ale)(4)) immobilized onto the surface of a glassy carbon electrode were studied, thus evidencing the ability of [Mo(2)O(2)S(2)]-based cycles to promote the reduction of protons into hydrogen, whereas the oxo analogue appeared inactive.
Institut Lavoisier de Versailles, UMR 8180, Université de Versailles Saint-Quentin en Yvelines, 45 avenue des Etats-Unis, 78035 Versailles Cedex, France.
Hani
H
El Moll
Justin Claude
JC
Kemmegne-Mbouguen
Mohamed
M
Haouas
Francis
F
Taulelle
Jérôme
J
Marrot
Emmanuel
E
Cadot
Pierre
P
Mialane
Sébastien
S
Floquet
Anne
A
Dolbecq
D002384:Catalysis; D056831:Coordination Complexes / Q000138:chemical synthesis* / Q000737:chemistry; D018360:Crystallography, X-Ray; D019281:Dimerization; D004164:Diphosphonates / Q000737:chemistry*; D055664:Electrochemical Techniques; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D008982:Molybdenum / Q000737:chemistry*
D056831:Coordination Complexes; D004164:Diphosphonates; D008024:Ligands; D008982:Molybdenum