1759-81-5Relevant articles and documents
Nickel Hydride Complexes Supported by a Pyrrole-Derived Phosphine Ligand
Collett, Joel D.,Guan, Hairong,Krause, Jeanette A.
, p. 345 - 353 (2022/02/16)
The synthesis of two nickel hydride complexes bearing the pyrrole-derived phosphine ligand CyPNH (2-(dicyclohexylphosphino)methyl-1H-pyrrole) was developed, namely, (κP-CyPNH)(κP,κN-CyPN)NiH and the acid-stable trans-(κP-CyPNH)2Ni(OAc)H·HOAc. (κP-CyPNH)(κP,κN-CyPN)NiH stoichiometrically reduces benzaldehyde and acetophenone in a metal-ligand cooperative manner and catalytically dimerizes ethylene and cycloisomerizes 1,5-cyclooctadiene and 1,5-hexadiene. trans-(κP-CyPNH)2Ni(OAc)H·HOAc, available from the protonation of (κP-CyPNH)(κP,κN-CyPN)NiH with acetic acid, catalyzes the cycloisomerization of 1,5-cyclooctadiene more effectively and produces the less thermodynamically favored cycloisomers of 1,5-cyclooctadiene.
Kinetics and modeling of the thermal reaction of propene at 800 K. Part III. Propene in the presence of small amounts of oxygen
Barbe,Baronnet,Martin,Perrin
, p. 503 - 522 (2007/10/03)
The thermal reaction of propene was studied around 800 K in the presence of less than 20% O. Initially, the production of H2, CH4, C2H4, C2H6, allene, C3H8, 1,3-butadiene, butenes, 3- and 4-methylcyclopentene, a mixture of 1,4- and 1,5-hexadienes, methylcyclopentane, 4-methylpent-1-ene, and hex-1-ene, was observed along with H2O2, CO, and small quantities of ethanal and CO2. O increases the initial production of H and of most hydrocarbons and, particularly, that of C6 dienes and of cyclenes. A kinetic scheme is proposed in which chains are primarily initiated by a bimolecular step which competes with the second-order initiation of propene pyrolysis. Modeling of the reaction based on the proposed scheme accounts well for the concentration-time profiles.
Formation de coke, desactivation et regeneration des zeolithes. IV - Transfert d'hydrogene et formation de coke au cours de la transformation du cyclohexene sur une zeolithe USHY. Influence de la temperature de reaction
Magnoux, Patrick,Gallet, Alain,Guisnet, Michel
, p. 810 - 814 (2007/10/02)
On a ultrastabilized protonic Y zeolite (USHY) cyclohexene undergoes various reactions: isomerization into methylcyclopentenes, hydrogen transfer, cracking and formation of carbonaceous deposits ("coke").The transfer of hydrogen which comes either from cyclohexene (with formulation of benzene) or from heavy carbonaceous compounds causes the saturation of cyclohexene and of methylcyclopentenes.While the total transformation rate increases when the temperature increases, the rate of coke formation decreases slightly.This abnormal effect can be due to a modification in the composition of heavy carbonaceous compounds held back in the zeolite pores.The relative significance of various reactions depends very much on the temperature: at 120 deg C "coke" formation is faster than isomerization and much faster than hydrogen transfer, the hydrogen implicated coming from heavy carbonaceous compounds only.From 200 deg C upwards, isomerization and hydrogen transfer become the main reactions.Even if the production of benzene increases significantly with the temperature, hydrogen always comes mainly from the heavy carbonaceous compounds and is transfered faster to methylcyclopentenes than to cyclohexene.Light compounds resulting from the cracking of methylcyclopentenes appear above 350 deg C.The formation of all the products can be explained by mechanisms in which carbenium ion intermediates intervene.
