The hexanuclear phosphido-bridged dication [Pt6(mu-PBu(t)2)4(CO)6](2+), (1)(2+), reacts under mild conditions with pseudo-halide anions (CN(-), NCO(-), NCS(-)) to afford the corresponding neutral bis-substituted clusters Pt6(mu-PBu(t)2)4(CO)4X2 (2, X = CN; 3, X = SCN; 4, X = NCO). The reaction with sodium azide affords 4, which may arise from the formation of the intermediate bis-azido derivative Pt6(mu-PBu(t)2)4(CO)4(N3)2, 5, and CO. These react rapidly with each other affording 4 and N2. Cluster 5 was alternatively prepared as a stable compound by reacting with NaN3 the neutral cluster Pt6(mu-PBu(t)2)4(CO)4(OTf)2, 14, which contains two weakly bonded triflate anions. As expected, 5 reacts with carbon monoxide (1 atm) affording cluster 4 instantaneously and quantitatively. The new pseudo-halide clusters 2-5, which are interesting potential precursors of cluster-containing molecular frameworks, have been characterized by IR and multinuclear NMR spectroscopy. The solid state structures of clusters 2-4 have also been studied by single-crystal X-ray diffractometry. The main features of the molecular structures remain similar to those of many related congeners described previously; in addition, an interesting reversible phase transition was observed in the crystal structure of cluster 3. As their known congeners, the clusters undergo two reversible one-electron reductions and an irreversible oxidation. An excellent linear correlation was found between the redox potentials of the cathodic processes and Lever's ligand parameter EL.

Synthesis and Electrochemical Characterization of Hexanuclear Platinum Bis-Pseudohalides

BONUCCELLI, VERONICA;FUNAIOLI, TIZIANA;LEONI, PIERO;MARCHETTI, FABIO;MARCHETTI, LORELLA;PASQUALI, MARCO
2013

Abstract

The hexanuclear phosphido-bridged dication [Pt6(mu-PBu(t)2)4(CO)6](2+), (1)(2+), reacts under mild conditions with pseudo-halide anions (CN(-), NCO(-), NCS(-)) to afford the corresponding neutral bis-substituted clusters Pt6(mu-PBu(t)2)4(CO)4X2 (2, X = CN; 3, X = SCN; 4, X = NCO). The reaction with sodium azide affords 4, which may arise from the formation of the intermediate bis-azido derivative Pt6(mu-PBu(t)2)4(CO)4(N3)2, 5, and CO. These react rapidly with each other affording 4 and N2. Cluster 5 was alternatively prepared as a stable compound by reacting with NaN3 the neutral cluster Pt6(mu-PBu(t)2)4(CO)4(OTf)2, 14, which contains two weakly bonded triflate anions. As expected, 5 reacts with carbon monoxide (1 atm) affording cluster 4 instantaneously and quantitatively. The new pseudo-halide clusters 2-5, which are interesting potential precursors of cluster-containing molecular frameworks, have been characterized by IR and multinuclear NMR spectroscopy. The solid state structures of clusters 2-4 have also been studied by single-crystal X-ray diffractometry. The main features of the molecular structures remain similar to those of many related congeners described previously; in addition, an interesting reversible phase transition was observed in the crystal structure of cluster 3. As their known congeners, the clusters undergo two reversible one-electron reductions and an irreversible oxidation. An excellent linear correlation was found between the redox potentials of the cathodic processes and Lever's ligand parameter EL.
Anselmi, M.; Bonuccelli, Veronica; Funaioli, Tiziana; Leoni, Piero; Marchetti, Fabio; Marchetti, Lorella; Mohapatra, S. K.; Pasquali, Marco
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11568/214338
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