2024-03-29T06:30:32Zhttps://repositori.uji.es/oai/requestoai:repositori.uji.es:10234/1598632021-07-01T15:38:46Zcom_10234_7013com_10234_9col_10234_8638
00925njm 22002777a 4500
dc
Alfonso Padilla, Carmina
author
Beltrán Álvarez, Tomás Francisco
author
Feliz Rodríguez, Marta
author
Llusar, Rosa
author
2015-01
Hydrido molybdenum and tungsten(IV) cluster cations of formula [M3S4H3(dppe)3]+ (dppe = 1,2-(bis)dimethylphosphinoethane), [Mo-1]+ (M = Mo) and [W-1]+ (M = W), have been isolated by reacting their halide precursors with borohydride. Synthetic procedures have been optimized by appropriate choice of the solvent. Furthermore, [M3S4F3(dppe)3]+ fluorido cluster complexes, [Mo-2]+ (M = Mo) and [W-2]+ (M = W) have been prepared through halogen substitution reactions using an excess of cesium fluoride. The structures of [Mo-1]+ and [Mo-2]+ have been determined by single crystal X-ray diffraction experiments. These [M-1]+ hydrido and [M-2]+ fluorido clusters have been used as catalysts and precatalysts, respectively, in the catalytic hydrodefluorination (HDF) of pentafluoropyridine using HSiMe2Ph as hydrogen source. The reaction proceeds under microwave and reflux conditions to selectively afford 2,3,5,6-tetrafluoropyridine. The [W-1]+ hydrido cluster is the most efficient catalyst with turnover numbers of 124, while the [Mo-1]+ hydrido cluster reacts faster. Fluorido [Mo-2]+ and [W-2]+ complexes provide lower yields and turnover numbers. In general, the molybdenum and tungsten [M-1]+ and [M-2]+ diphosphino complexes are more efficient than their dmpe (1,2-(bis)dimethylphosphinoethano) analogues and activate pentafluoropyridine under softer conditions
ALFONSO, Carmina, et al. Influence of the Diphosphine Coordinated to Molybdenum and Tungsten Triangular M3S4 Cluster Hydrides in the Catalytic Hydrodefluorination of Pentafluoropyridine. Journal of Cluster Science, 2015, vol. 26, no 1, p. 199-209.
http://hdl.handle.net/10234/159863
http://dx.doi.org/10.1007/s10876-014-0733-1
Catalytic hydrodefluorination
Cluster sulphides
Group six metals
Hydrides
Fluorides
Influence of the Diphosphine Coordinated to Molybdenum and Tungsten Triangular M3S4 Cluster Hydrides in the Catalytic Hydrodefluorination of Pentafluoropyridine