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On-line molecular beam mass spectrometry was used to investigate the kinetics and mechanism of the heterogeneous oxidation of ethane and ethylene on samarium(III) oxide. Findings show that a similar mechanism is at work in the heterogeneous oxidations of ethane and ethylene and the oxidations of methane and methyl radicals. Distinguishable surface species with different reactivities toward each hydrocarbon is created by endothermic O2 dissociative chemisorption. Under most conditions, a faster oxidation rate is observed for ethane and ethylene, compared with methane. Activation energies for the rate determining steps increase with R-H bond energies.

The diethylenetriaminepentaacetic acid (DTPA) analogues dipropylenetriaminepentaacetic acids (DPTPA) can be synthesized by the acyl coupling of substituted alanines or glycines, followed by the reduction of the amide and the hydrolysis of the esters. Alkylation of (S)-propylenediaminetriacetic acid triester led to the formation of oxazoloisoindole. Phthaloyl deprotection with subsequent dialkylation produces ester-differentiated (S,S)-dipropylenetriaminepentaacetic esters.

The alkyne-alkyne cross coupling occurs for the reaction of Cp2ZrBu2 and ethylene gas. This type of cross-coupling is highly selective in nature. Treatment of Cp2ZrBu2 with ethylene gas gives zirconacyclopentanes. Simultaneous addition of the second alkyne to zirconacyclopentenes solution gives asymmetrical zirconacyclopentadienes. The product yields are very high especially after hydrolysis of the resulting solution.

Geometrical optimization of complexes produced by Diels-Alder reactions of Mo(2) with 1, 3-butadiene and ethylene reveal elongations of the Mo-Mo and C double bond C bonds in the complexes. The bond distances are close to those in organomolybdenum complexes. Analysis of potential energy surfaces for interactions of low lying excited states of Mo2 with ethylene and 1, 3-butadiene reveals that formation of an Mo2-Eth complex through an excited state is thermally forbidden. Addition of thermal energy helps form Mo2-But complex in the ground state.

Ab initio molecular dynamics simulations of ethylene insertion into a bridged dicyclopentadienylmethylzinconocene reveal that the reaction occurs within 150 femtoseconds. Theoretical calculations reveal the absence of energy barrier between the reactant pi-complex and the product state. The studies show the flexibility of the Cp rings. Gamma-H agostic interactions stabilize the product.

Analyses of tetraethoxysilane (TEOS) vapor, directed at the adsorption and reactions on clean and water-predosed rutile TiO2 involved the use of X-ray photoelectron diffraction and temperature-programmed desorption. TEOS dissociates upon heating at low coverage, with marginal desorption at greater coverages. Si(OEt)2,s plus 2EtOs (Et = C2H5) are the initial products of the rapid dissociation reaction which takes place between 200 and 350 K on the water- and hydroxyl-free surface.

SCF, SCF/MP2, QCISD and MCSCF methods were used at 4-31G and 6-31+G levels to theoretically examine the mechanism of the reaction between ethylene and nitronium ion. A bridged pi complex is situated over long-range electrostatic complex at the QCISD level. The site of the sigma-bonded species is a transition-state site for the development of a CCNO four-membered-ring.

1,1-diarylethelenes in acetonitrile are photooxygenated by sensitized 9,10-dicyanoanthracene at various rates to produce different derivatives. Excess amounts of 3,3,6,6-tetraaryl-1, 2-dioxanes are produced when an electron-donating substituent is transported by any of the aryl classes at the para or ortho location. Benzophenone, an obvious derivative, is derived from 1,1-Diphenylthylene and its m-methoxy, p-chloro and p-nitro products. Biphenyl must occur for the p-nitro group to yield benzophenones. Extra derivatives are 1,2-dioxanes, cyclobutanes and alpha-tetralones. Oxygenations stimulated by electron-transfer yield dioxanes, benzophenones and alpha-tetralones. Triplet ground-state molecular oxygen, (super 3)O(sub 2), participates in the oxygenations.

An analysis of the reaction of ethylene (Et) and its radical cation (Et.+) supports prior experimental findings in showing that the primary product of this reaction is a pi complex cation (Et...Et).+ in which the two Et molecules are connected by one bond of around 19 angstrom, and which is held together by 18.2 kcal/mol compared to Et + Et.+.

Fourier transform mass spectrometry provided insight into the gas-phase chemistry of Sc(CH3)2+ with alkenes. Ethylene is the only alkene examined that reacts with Sc(CH3)2+ through a multi-centered eta-bond metathesis mechanism to stimulate allylic C-H bonds. The metal (1-butene)isomer is between 10 and 20 kcal/mol less stable than the metal(methyl)(allyl) structure.

The effects of changing the c(sub 2)D(sub2) concentration, electron flux, pH, or the individual presence of N(sub 2), ethylene, or CO on the formation of both cis- and trans-1,2-ethylene-d(sub 2) from C(sub 2)D(sub 2) are monitored. The factors influencing stereoselective protonation during C(sub 2)D(sub 2) reduction is the same as that of the FeMo cofactor when acetylene is reduced.

New phosphinitooxazoline and -pyridine ligands were used for the synthesis of mononuclear and dinuclear Ni(II) complexes, which were evaluated in the catalytic oligomerization of ethylene. The observed selectives for the C4 dimers were as high as 92% (for 14 or 15 in the presence of only 1.3 equiv of AIEtCl(sub 2).

The spontaneous dimerization of multiply-bonded Al-N hydrides requires a zero activation energy with dative-bond dimerization energies that are similar to Al-N adducts. The Al-N analogs of acetylene and ethylene exhibited a planar geometry with a trans-bending distortion to the bent HAlNH structure as indicated by Moller-Plesset perturbation theory. Analysis of the Al-N bond in the H2AlNH2 analog indicated the presence of a slightly strained structure while Al2N2 exhibited a planar ring with a puckered conformation.

Tetracyanoethylene (TCNE) in combination with donors of azoalkane N-oxide and an azoalkane N,N'-dioxide of DBO form cyclic donor-acceptor (DA) complexes in the solid state showing aromatic pericyclic array properties. Pericyclic analysis is sufficient to predict the observed topology of cyclic DA interaction in some cases.

Symmetry forbidden (2 + 1) cycloaddition of ethylene to ethylene radical cation with forced D2h symmetry results in cyclobutane radical cation intermediates. These intermediates are stabilized with pagodanes or isomeric dienes due to light or extended binding. Ab initio calculation shows that the extended pagodane and tight isopagodane radical cations are stable. ESR spectroscopy helps study the geometry of the stabilized intermediates.

Variable temperature multinuclear NMR analysis and relaxation time measurements of (Rh(acac)C2H4)2 reveals that ethylene ligands exhibit both vibrational motion and rotation in solution and solid state. Rh(acac)(cod) does not reveal rotation, but undergoes a vibrational motion about its equilibrium binding position. Spectroscopic data at different temperatures show that free energy change is 56.5 KiloJoules per mol at 298 K.

Bulk H atoms which move out from bulk metal to the surface catalyze the hydrogenation of ethylene absorbed on Ni(111) surfaces. Bulk H specifically acts as a reactant on a transition metal in this reaction. The rough surfaces of the crystals facilitate hydrogenation. A comparative analysis is performed between the hydrogenation activity of bulk H and surface-bound H.

Analysis of C-H bond activation and ethylene bonding to d to the power of O transient (silox)2Ti double bond NSitBu3 reveals that the involvement of ancillary silox(tBu3SiO-) ligands provides a chemically varied titanium imido system. Sequential stoichiometric additions of Na(silox) and (tBu3SiNH) to TiCl4(THF)2 provide chloride (silox)2(tBu3SiNH)TiCl.

HNMR spectroscopic studies of the intermediate (HRh(CO)2I3)(AsPH4) and its reaction with ethylene resulted in an analysis of the olefin/rhodium hydride pathway for the Rh-catalyzed ethylene carbonylation reaction. Intrared analysis of the intermediate revealed a single Co stretching frequency at 2080/cm. The NMR spectra reveals a high-field proton resonance consistent with intermediate formation.

The rate of polymerization of ethylene in derivatives of organorhodium complexes consisting of a facially-coordinating tridentate ligand 1,4,7-trimethyl-1,4,7,triazacyclononane (Cn) is very slow. The organorhodium complexes include CnRhMe3, CnRhMe2 (OTf) and CnRhMe (OTf)2. The rhodium methyl bond of the latter two compounds are subjected to ethylene incorporations. CnRhMe2(OTf) and CnRhMe(OTf)2 are characterized by a well-defined chemistry in a solution of methanol. In water compound, the three forms dehydrate. Ethylene polymerizations are coordinately catalyzed by the compound three and its derivatives.