- Ylidylphosphanes and -diphosphanes
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Chlorophosphanyl and dichlorophosphanyl alkylidene- and benzylidenephosphoranes 6 and 8 are converted by reaction with LiAlH4 to the respective phosphanes 7 and 9. The former can be isolated, but decompose on heating or on protonation to give the ylidyl diphosphane 11 and the phosphonium ylide or phosphonium salt, respectively. The final products are the cyclooligophosphanes 15-17. Only the C-tert-butyl derivative 7c is stable in both regards. The conformation of the RPH group in 7 as compared to that of the RPCl group in 6 clearly reflects their different interaction with the ylide moiety.
- Breitsameter, Florian,Schmidpeter, Alfred,Schier, Annette
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p. 381 - 388
(2007/10/03)
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- OBERFLAECHEN-REAKTIONEN 15 Heterogene Dechlorierungen von Phosphorchloriden (X)PCl3 und R-PCl2 an , , x/TiO2> und sowie spektroskopische Evidenz fuer das Entstehen von Diphospha-dicyan PC-CP aus Cl2P-CC-PCl2
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Stimulated by the successful generation of unsaturated molecules with low-coordinated phosphorus centers by heterogeneous surface dechlorination, Cl2P-CC-PCl2 is synthesized and characterized by PE and mass spectra.In addition, curls, wool and catalysts x/TiO2> or are tested as potential dechlorinating agents for phosphorus halides like OPCl3, SPCl3, H3C-PCl2, H5C2-PCl2, (H3C)3C-PCl2 or H5C6-PCl2 in a gasflow reactor under reduced pressure and yield, inter alia, the following representative results: due to the thermodynamically favored formation of , or at the Mg surface, P4 is the only gaseous product identified from reactions of OPCl3 and SPCl3 with metal at higher temperatures.On the contrary, passing H3C-PCl2 at 600K over yields a reaction mixture containing P(CH3)3, (H3C)2P-P(CH3)2 (H3C-P)5 and CH4, which suggests an intermediate formation of surface phosphinidenes Mg>.Analogously, the pentamer (H3C-H2C-P)5 can be isolated from ethyldichlorophosphane.Reaction of the evaporated diphospha-cyanogen precursor Cl2P-C-PCl2 with the catalyst produces predominantly PCl3, and P4, but PE and mass spectra provide evidence that also minor amounts of the hitherto unknown molecule PC-CP are formed.
- Bock, H.,Bankmann, M.
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p. 167 - 191
(2007/10/02)
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- Evidence for Surface Phosphinidene Intermediates Mg> in the Heterogeneous Dechlorination of Alkyldichlorophosphanes RPCl2 by Mg Metal
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The heterogeneous dechlorination of alkyldichlorophosphanes by Mg metal at 600 K yields chemisorbed products which include penta-alkylcyclopentaphosphanes (RP)5, in addition to RnPH(3-n), R2P-PR2, P4, RH, and R-R, and thus provides evidence for surface phosphinidene intermediates Mg>.
- Bock, Hans,Bankmann, Martin
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p. 1130 - 1132
(2007/10/02)
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