0000000000138920
AUTHOR
Francesco Vizza
Hydrierung von weißem Phosphor zu Phosphan mit Rhodium- und Iridiumtrihydriden
Nur eines der vier P-Atome von P4 wird bei der Reaktion mit den Trihydriden [(triphos)MH3] (M = Rh, Ir) zu Phosphan umgesetzt [Gl. (a)]. Das zuruckbleibende cyclo-P3-Fragment wird vom entsprechenden Metallfragment unter Bildung der Komplexe [(triphos)M(η3-P3)] abgefangen. Fur die Hydrierung wird ein Mechanismus vorgeschlagen, bei dem die Komplexe [(triphos)MH(η1:η1-P4)] und [(triphos)M(η1:η2-HP4)] als Zwischenstufen auftreten; die letztgenannten Komplexe enthalten den neuartigen Hydridotetraphosphanliganden HP4−.
Hydrogenation of White Phosphorus to Phosphane with Rhodium and Iridium Trihydrides.
Only one of the four P atoms of P4 reacts with rhodium and iridium trihydrides [(triphos)MH3 ] to provide phosphane [Eq. (a)]. The resulting cyclo-P3 fragment is efficiently scavenged by the metal fragment to give the complexes [(triphos)M(η3 -P3 )]. A mechanism accounting for the hydrogenation reaction is proposed in which the complexes [(triphos)MH(η1 :η1 -P4 )] and [(triphos)M(η1 :η2 -HP4 ] are intermediates. The latter complex contains the unprecedented hydridotetraphosphane ligand HP4- .
Recycling ground tire rubber (GTR) scraps as high-impact filler of in situ produced polyketone matrix
A sustainable procedure for recycling powdered rubber coming from scrap tires (ground tire rubber [GTR]) is proposed as based on the dispersion in polyketone (PK) matrix, obtained in situ by CO/ethylene copolymerization. Three types of catalysts are used operative in solvents of different polarities. The catalyst productivity and the hybrids morphology are evaluated and optimized to final composites features. The obtained products are characterized by scanning electron microscopy, atomic force microscopy, and solvent extractions in order to investigate the occurrence and the extent of interactions between PK macromolecular chains and the GTR components; and their effects on the final proper…
Amino-phosphanes in RhI-Catalyzed Hydroformylation: Hemilabile Behavior of P,N Ligands under High CO Pressure and Catalytic Properties
International audience; The catalytic properties of rhodium complexes containing the α-, β-, or γ-amino-phosphane ligands Ph2PCH2NEt2 (α-P,N-1), Ph2PCH(Ar)NHPh [α-P,N-2; Ar = η6(o-C6H4Cl)Cr(CO)3], Ph2PCH2NPh2 (α-P,N-3), Ph2PCH2CH(Ph)NHPh (β-P,N), Ph2PCH2(o-C6H4–NMe2) (γ-P,N-1), Ph2PCH(o-C6H4–CH2NHPh) (γ-P,N-2), and the α,β-diamino-phosphane ligand Et2NCH2P(Ph)CH2CH(Ph)NHPh (α,β-N,P,N), in styrene hydroformylation have been examined. The results show that the activity increases when the number of backbone carbon atoms linking P and N decreases from 3 to 1. IR and 31P HPNMR studies in solution show that all P,N ligands adopt exclusively a κ1-P coordination mode in rhodium chloride carbonyl co…