14457-64-8Relevant academic research and scientific papers
Gas-Phase Reaction between Hydrocarbons and Metal Oxides: The AlO + CH4 Reaction from 590 to 1380 K
Belyung, David P.,Fontijn, Arthur,Marshall, Paul
, p. 3456 - 3459 (1993)
A recent ab initio study suggested that gaseous metal oxides can directly abstract H atoms from hydrocarbons, but with considerable barriers.To try to confirm the occurrence of such reactions, the title reaction has been studied in a high-temperature fast-flow reactor.The data are well described by a fitting expression k(590-1380 K) = 9.6 * 10-39(T/K)7.96 exp(2468 K/T) cm3 molecule-1 s-1, with 2? precision limits varying with temperature from +/- 4percent to +/- 12percent.The corresponding 2? accuracy limits are about +/- 25percent.Comparison of this result to further ab initio and conventional transition-state theory calculations suggests that direct abstraction indeed can occur at the higher temperatures but that one or more other channels, possibly involving AlO insertion into a C-H bond, dominate in the initial attack step.The potential implications of this work for catalytic conversion of methane to higher hydrocarbons are considered.
Infrared Matrix-Isolation Studies of the Interactions and Reactions of Group 3A Metal Atoms with Water
Hauge, R. H.,Kauffman, J. W.,Margrave, J. L.
, p. 6005 - 6011 (1980)
It has been shown that aluminium atoms react spontaneously with H2O at 15 K while the heavier group 3A metals form M(*)OH2 and M2(*)OH2 adducts.Adduct formation causes the ν2-bending mode of H2O to decrease by 21.4, 16.5, and 9.6 cm-1 for Ga, In, and Tl and 14.4 and 10.6 cm-1 for Ga2 and In2, respectively.The divalent HAlOH molecular species is formed from reaction of the aluminium atom with water.The HGaOH and HInOH molecular species are formed by photolysis of the respective adducts while the Tl(*)OH2 adduct does not react on photolysis.The monovalent molecular species MOH is readily formed by further photolysis of the divalent HMOH species.Molecular vibrational frequencies and mode assignments are given in accompanying tables.Data suggest that the diatomic Ga2, In2, and Tl2 adducts with water readily rearrange when photolyzed to a hydrogen-bridged dimetal species, which in turn is converted to the M2O molecular species by further photolysis.
Electron spin resonance matrix isolation studies of 27Al16,17O, 69,71Ga16,17O and 115In16,17O: Observed hyperfine interactions compared with ab initio theoretical results
Knight Jr., Lon B.,Kirk, Thomas J.,Herlong, John,Kaup, John G.,Davidson
, p. 7011 - 7019 (2007/10/03)
Electron spin resonance (ESR) studies are reported for Al16,17O, Ga16,17O, and In16,17O isolated in neon matrices at 4 K. Except for Al16O, no previous ESR measurements have been reported for these X 2Σ diatomic radicals. The pulsed laser vaporization of the metals in the presence of 16O2 and 17O2 produced high quality ESR spectra of these metal oxide radicals whose nuclear hyperfine interactions (A tensors) were fully resolved for both the metal and oxygen nuclei. An analysis of the experimental spin densities in combination with different types of theoretical calculations provided detailed information concerning the electronic structure trends going down this metal oxide group. Increased p-orbital spin density on oxygen was observed for the heavier metal oxide radicals. Nonrelativistic ab initio calculations with an extended basis set and the UB3LYP method reproduced the trends in the isotropic and dipolar hyperfine interactions. All-electron CI calculations, restricted open-shell Hartree-Fock (ROHF) wave functions, and unrestricted Hartree-Fock wave functions gave results very different from experiment and from each other for the isotropic interaction. All calculations were in fair agreement with each other for the dipolar interaction and provided an assignment of the sign for that term.
Electronic transition moment of the AlO(B(2)Σ(+)-X(2)Σ(+)) emission. Analysis of the R dependence of the Al(2+)O(2-) character in the X(2)Σ(+) state
Sato, Noriko,Ito, Haruhiko,Kuchitsu, Kozo
, p. 10 - 16 (2008/10/08)
The dependence of the electronic transition moment, R(e)(R), of the AlO(B(2)Σ(+)-X(2)Σ(+)) system on the internuclear distance, R, has been determined by an analysis of the intensity distribution of the emission spectra as R(e)(R)=[1-2.29(13)(R/?-1.5)**2]
Reactivities of spin-orbit states in Al((2)P(1/2,3/2))+O2(X(3)Σ(-)(g))AlO(X(2)Σ(+))+O((3)P(0,1,2)). A fluorescence imaging study
Chen, Kuo-mei,Sung, Chun-hwa,Chang, Jia-lin,Chung, Teng-hui,Lee, Kuo-huei
, p. 17 - 24 (2008/10/08)
A crossed beam chemical reaction, Al((2)P(1/2,3/2))+O2(X(3)Σ(-)(g)) AlO(X(2)Σ(+))+O((3)P(0,1,2)) was investigated by fluorescence imaging techniques. Multiplex detection of speeds and quantum states of both reactants and products has been implemented. The
Kinetics of the Reaction Al(2PO) + H2O over an Extended Temperature Range
McClean, Roy E.,Nelson, H. M.,Campbell, Mark L.
, p. 9673 - 9676 (2007/10/02)
The temperature dependence of the reaction Al(2PK0) + H2O has been investigated over the temperature range 298-1174 K.Aluminium atoms were produced by photodissociation of Al(C2H5)3 and were detected by laser-induced fluorescence.Non
Reactions of Pulsed-Laser Evaporated Aluminium Atoms with Oxygen. Infrared Spectra of the Reaction Products in Solid Argon
Andrews, Lester,Burkholder, Thomas R.,Yustein, Jason T.
, p. 10182 - 10189 (2007/10/02)
Reactions of pulsed-laser evaporated Al atoms with O2 in a condensing argon stream gave cyclic-AlO2 at 496.3 cm-1 as the major product.In addition sharp new absorptions at 1211.2, 1176.3, and 1129.5 cm-1 are identified on the basis of isotopic shifts and multiplets as linear OAlOAlO, AlOAlO, and OAlO, respectively.The identification of linear OAlOAlO and AlOAlO was confirmed by MP2 calculations of isotopic frequencies.The 1129.5 cm-1 band exhibited a sharp mixed oxygen isotopic triplet and isotopic ratio 1.0261 in agreement with that expected for a linear molecule.A sharp 1092.5 cm-1 absorption is identified as OAlOO on the basis of a mixed oxygen isotopic quartet with 16O2/16O18O/18O2 and 16O2/18O2 reagent mixtures.The only AlO2 isomers observed were the cyclic and linear forms found by theory to be potential minima.The observation of isotopic shifts and mixed isotopic multiplets is absolutely essential for the identification of new transient species.
Formation and Oxidation of Metal-Based CO and CO2 Complexes: Characterization of Al(CO)x and Al(CO2)x and their Oxidation
McQuaid, M.,Woodward J. R.,Gole, J. L.
, p. 252 - 255 (2007/10/02)
In a comparative study, aluminum atoms entrained in argon, CO, and CO2 are oxidized with ozone to inspect the nature of aluminum complexation with CO and CO2 to form Al(CO)x (x= 1, 2) and AlCO2 adducts.The optical signatures corresponding to the chemiluminescent oxidation of these complexes with ozone to form the AlO B2Σ+ state or, in the case of CO2, a polyatomic complex are compared to that AlO B2Σ+ emission associated with the chemiluminescent oxidation of nonbonded aluminum atoms in argon.We (1) establish a method for evaluating M(CO)x binding energies and (2) observe the optical signature for a potentially long-lived (ca. 1E-7 s) metal oxide-carbon dioxide solvation complex formed in metal-CO2 complex oxidation.From a comparison of these studies, with results obtained for Al-N2O oxidation, we estimate a lower bound to the total (Al(CO)2 binding energy (to Al+2CO) of ca.0.7 eV.The current study in conjunction with parallel efforts involving the transition metals suggests a method for studying the spectra of MCO, M(CO)2, and M-CO2 complexes.
Spectroscopic studies of AlO in argon matrices
Bares, S. J.,Haak, M.,Nibler, J. W.
, p. 670 - 675 (2007/10/02)
The diatomic species AlO has been isolated in argon at 18 K as an Al + O2 reaction product and shown to produce intense laser induced fluorescence in the visible.An infrered-optical double resonance experiment has established the X state vibrational fundamental at 975 cm-1, one of four possibilities previously proposed from infrared studies. 18O experiments further establish the assignment.The apparent low infrared intensity of the AlO stretch is consistent with a recent ab initio calculation of an oscillator strenght of 4*10-7.This anomalously low value is confirmed by comparison of infrared and visible absorption intensities for similar samples.A v = 1 lifetime in excess of 6 ms was directly measured for AlO by the double resonance method.This slow rate of radiative relaxation makes AlO attractive as a probe molecule for vibrational relaxation studies.
MATRIX-ISOLATION STUDIES BY ELECTRONIC SPECTROSCOPY OF GROUP IIIA METAL-WATER PHOTOCHEMISTRY
Douglas, Monte A.,Hauge, Robert H.,Margrave, John L.
, p. 1533 - 1554 (2007/10/02)
This paper reports an investigation of the electronic structures of the Group IIIA metal atom hydration reaction intermediates (MOH2 adducts) and their subsequent photolysis products (HMOH, MOH and MO) where M = Al, Ga and In.The metal-water interaction in the adduct is sufficiently strong to perturb the electronic structure of the metal atom; consequently, one observes a unique band structure for the adduct that is red shifted from the metal's atomic resonance transition.Molecular orbital and electronic state-to-state correlations are presented.
