Hydrodesulfurization catalysis over ternary molybdenum chalcogenides

An Improved High Yield Synthesis Procedure and Reactivity of W6S8(4-tert-butylpyridine)6

“…We chose triethylphosphine and piperidine as ligands to probe the lability of the W-N bond in W 6 S 8 (4-tert-butylpyridine) 6 . At room temperature, the replacement of 4-tert-butylpyridine on the cluster with triethylphosphine and piperidine is extremely slow.…”

“…Octahedral clusters of molybdenum that are face-capped by sulfur (Mo 6 S 8 units) form intercluster metal−sulfur interactions in an important class of solid-state compounds called “Chevrel Phases” . These compounds possess exciting electronic properties such as superconductivity and are known to be catalysts in the hydrodesulfurization reaction. − Although the Chevrel phases are generally synthesized using conventional solid-state techniques, in recent years it has been shown that the constituent Mo 6 S 8 clusters can be synthesized as isolated units in solution. , Similar chromium and tungsten chalcogenide cluster units have also been synthesized even though their corresponding Chevrel phases are unknown. − Based on the gamut of properties that the Chevrel phases exhibit, these soluble isolated cluster units offer an opportunity to synthesize new materials from these building blocks.…”

“…1 These compounds possess exciting electronic properties such as superconductivity 2 and are known to be catalysts in the hydrodesulfurization reaction. [3][4][5][6][7] Although the Chevrel phases are generally synthesized using conventional solid-state techniques, in recent years it has been shown that the constituent Mo 6 S 8 clusters can be synthesized as isolated units in solution. 8,9 Similar chromium and tungsten chalcogenide cluster units have also been synthesized even though their corresponding Chevrel phases are unknown.…”

Synthesis, characterization and properties of Mo6S8(4-tert-butylpyridine)6 and related M6S8L6 cluster complexes (M = Mo, W)

“…Octahedral molybdenum chalcogenide clusters (Mo 6 Q 8 , Q = S, Se, Te) are the building blocks of the Chevrel phases 1 that are well-known for their superconductivity, 2 fast ionic conductivity, 3,4 thermoelectric properties 5-7 and catalytic activity. [8][9][10][11] Molecular Mo 6 S 8 L 6 clusters (L = PEt 3 , nitrogen Lewis base ligands) were prepared independently by Saito and coworkers 12, 13 and by McCarley et al 14 to study their structural relation to the solid-state Chevrel phases and to use these molecular precursors to prepare Chevrel phases. 15, 16 However, these two synthetic procedures are not ideal for further studies of the solution chemistry of the clusters.…”

Reduced molybdenum oxidation states in hydrodesulfurization catalysis by Chevrel phases

“…Chevrel phases-has been reported previously [115][116][117][118][119][120][121][122][123]. Direct preparation of catalysts with reduced molybdenum oxidation states (relative to Mo'^"'" in M0S2) is possible with these materials.…”