1117-89-1Relevant academic research and scientific papers
THE MICROWAVE SPECTRUM AND STRUCTURE OF PROPYLENE OXIDE
Imachi, M.,Kuczkowski, R. L.
, p. 55 - 60 (1982)
The rs and r0 structural parameters have been determined for propylene oxide from rotational constants for 16 isotopic species.The heavy-atom (r0) parameters are: r(C1C2) = 1.470(3), r(C2C3) = 1.505(2), r(C1O) = 1.441(2), r(C2O) = 1.435(3) Angstroem, angle OC1C2 = 59.1(2), angle OC2C1 = 59.4(1), angle C1OC2 =61.5(2), angle C1C2C3 = 121.7(2), angle OC2C3 = 116.1(2) degree.The methyl group torsional angles with the ring are: τ(C1C2C3H9) = 24.7(8) and τ(OC2C3H9) = -44.0 degree (5).These parameters agree closely with analogous results for ethylene oxide.
Marked Size Effect of Zinc Oxide Particles Supported on Silica in Propene-Deuterium Addition and Exchange Reactions
Naito, Shuichi,Tanimoto, Mistutoshi,Soma, Mitsuyuki
, p. 1443 - 1445 (1992)
Small particles of ZnO trapped between silica particles exhibit a marked size effect on the reaction rates as well as on the reaction intermediates of the propene-deuterium addition and exchange reactions.
Marked Changes of Reaction Intermediates caused by Alloying: Deuterium Addition and Exchange of Propene over Ni-Cu, Pd-Cu, and Pt-Cu Catalysts
Naito, Shuichi,Tanimoto, Mitsutoshi
, p. 363 - 365 (1987)
Microwave spectroscopic analysis of the monodeuteriopropene formed during C3H6-D2 reaction over Ni-Cu, Pd-Cu, and Pt-Cu catalysts disclosed marked changes in the reaction intermediates for deuterium addition and exchange caused by alloying.
Mechanism of Deuterium Addition and Exchange of Propene over Silica-supported Gold and Silver Catalysts
Naito, Shuichi,Tanimoto, Mitsutoshi
, p. 4115 - 4124 (1988)
The mechanism of the C3H6-D2 reaction over silica-supported Au and Ag catalysts has been studied by applying microwave spectroscopy as well as kinetic measurements.A large kinetic isotope effect was observed for the rate of propane formation between the C3H6-H2 andC3H6D2 reactions, indicating that the hydrogen dissociation is the rate-determining step.Both deuterium addition and exchange processes proceeded via an associative mechanism involving n-propyl as well as s-propyl species, although the methyl hydrogen of propene was less active for exchange through this process.In addition, intramolecular 1,3- and 2,3-hydrogen-shift processes were observed for the first time; they proceeded only in the presence of gaseous hydrogen and caused the exchange of the methyl hydrogen of propene.The characteristic features of supported Group IB metals in this reaction are compared with those of Group VIII metals, and the possible structures of reaction intermediates are discussed in detail.
Remarkable Dispersion Effect of TiO2 Catalyst on Silica Support in Propene - Deuterium Addition and Exchange Reaction
Naito, Shuichi,Tanimoto, Mitsutoshi
, p. 2145 - 2148 (1990)
Investigation on the effect of dispersing small particles of TiO2 over silica upon the rate and mechanism of propene-deuterium reaction revealed that lower loading catalysts (1-8 wtpercent) exhibit markedly different catalytic behavior from that over unloaded TiO2.
Synergetic Ligand Effect in the Hydrogen Exchange Reaction of Propene over Pd-Cu and Pt-Cu Alloy Catalysts
Naito, Shuichi,Tanimoto, Mitsutoshi
, p. 411 - 414 (1988)
Marked changes of reation intermediates on alloying were disclosed by the microwave spectroscopic analysis of the monodeuteriopropene formed during C3H6-C3D6 exchange reaction over Pd-Cu and Pt-Cu alloy catalysts.
Novel Support Effects on the Mechanism of Propene-Deuterium Addition and Exchange Reactions over Dispersed ZrO2
Naito, Shuichi,Tanimoto, Mitsutoshi
, p. 306 - 313 (1995)
The effect on the rate and mechanisms of propene-deuterium reactions of dispersing ZrO2 on various supports such as silica, alumina, and titanium dioxide has been studied by microwave spectroscopic analysis of monodeuteropropene as well as by kinetic investigation.By dispersal of ZrO2 on these supports, the rate of the C3H6-D2 reactions is increased considerably compared to that over unsupported ZrO2, with the decrease of activation energy.Hydrogen exchange in propene proceeds simultaneously with addition via the associative mechanism through n-propyl and s-propyl intermediates.Through XPS analysis of ZrO2/SiO2, it was found that a monolayer of ZrO2 is formed over the silica support.The monolayer catalyst exhibits catalytic behavior quite different from that of unsupported ZrO2.On the other hand, alumina surfaces modified by ZrO2 layers may be the main active sites in the case of ZrO2/Al2O3.The marked enhancement of the reaction rate in the lower loading region of ZrO2/TiO2 may be explained by the strong interaction of atomically dispersed zirconium ions with active centers on TiO2
Protonation of C3H6 Isomers: Isotope Exchange and Isomerization
Hunter, Edward P.,Lias, S. G.
, p. 2769 - 2775 (1982)
Isotope exchange processes of the type (MH+ + C3D6 -> MD+ + C3HD5) or (MD+ + C3H6 -> MH+ + C3H5D) (where C3(H,D)6 is propylene or cyclopropane) have been studied in an ICR spectrometer.It is shown that, for both reactant molecules, the efficiency of the exchange reaction can be correlated with the exothermicity of the formation of the complex C3(H,D)7+> from separated M(H,D)7+ and C3(H,D)6 reactants.In the case of propylene, all of the M(H,D)+ reactants are chosen so that proton (deuteron) transfer is endothermic.For cyclopropane reactant molecules, some of the reactant pairs have available an exothermic channel leading to the formation of a sec-propyl ion product, but this process is shown to compete poorly with the isotope exchange process ( which may or may not involve isomerization of the neutral cyclopropane to propylene in the collision complex).Isotope exchange reactions involving the partially deuterated propylenes CD3CH=CH2, CH3CH=CD2, and CH3CH=CHD provide evidence that, when M is a nitrile, there is statistical scrambling of the H and D atoms in the C3(H,D)7+ in the sec-C3(H,D)7+> complex; when M is an aldehyde or a formate, the reaction involves only the H and D atoms on the methyl groups of the sec-C3(H,D)7+ species in that complex.Experiments with 1,1-C3D2H4 indicate that the isotope exchange process involves a single C(H,D)2 group in the cyclopropane molecule, except when proton transfer is exothermic.Rate constants are reported for a number of proton-transfer reactions involving cyclopropane.
Deuterium kinetic isotope effects on the thermal isomerizations of deuteriocyclopropane to deuterium-labeled propenes
Baldwin, John E.,Singer, Stephanie R.
, p. 1510 - 1515 (2005)
The gas-phase thermal isomerizations of deuteriocyclopropane to the four possible monodeuterium-labeled propenes have been followed at 435°C. The observed distribution of products provides estimates of two deuterium kinetic isotope effects, the secondary ksh/ks D for the carbon-carbon bond cleavage leading to trimethylene diradical reactive intermediates and the primary kp h/kpD ratio for a [1,2] shift of a hydrogen or deuterium leading from the diradical to a labeled propene. The values determined are ksD/ksD = 1.09 ± 0.03 and kpH/kpD = 1.55 ± 0.06. The experimental ksD/ksD value found agrees well with some, but not all, earlier calculated values and conjectures.
Carbon Acidity. 58. Hydrogen Isotope Exchange Kinetics of Propylene with Lithium Cyclohexylamide
Boerth, Donald W.,Streitwieser, Andrew Jr.
, p. 6443 - 6447 (1981)
Rates for hydrogen isotope exchange with lithium cyclohexylamide (LiCHA) in cyclohexylamine-N,N-d2 (CHA-D2) and cyclohexylamine (CHA) are compared for propene and toluene.Benzyl hydrogens in toluene were found to be 6.2 times more reactive than allyl hydrogens in propene.Experimental primary isotope effects are also reported for propene: kD(exptl)/kT(exptl)=2.9, kH(exptl)/kT(exptl)=30, and kH(exptl)/kD(exptl)=10.2.Derived internal return values show comparable values for propene and toluene.Analysis of polydeuteration rates shows that exchange is accompanied by complete equilibration of allyl positions.The high isotope effects and comparable acidities and internal return imply a transition state for propene which resembles that of toluene.An equilibrium pKa on the CsCHA scale of ca. 43 is deduced for propene.
