Recombination of carbon monoxide and oxygen atoms

The recombination of carbon monoxide and oxygen atoms was studied in reflected shock waves in H₂:O₂:CO:Ar = 0.1:1:24:75 with 1300 < T₅ 2200 K and 2 < P₅ < 4 atm. Reaction progress was monitored by observations of the carbon monoxide flame spectrum near 435 nm and carbon dioxide thermal emission near 4.2 μm. Data analysis was accomplished with the aid of computer modeling using a 27-reaction mechanism. Computer modeling experiments also showed that these measurements were sensitive primarily to the rate of the reaction CO + O + M = CO₂ + M and only slightly sensitive to the rates of other reactions. The best fit to the data was achieved with a rate constant for this reaction of 7.7 × 10^?35 exp[19 kJ/RT] cm⁶ s for the temperature range of these experiments. Correlation of this result and previous data covering the temperature range 250 < T < 11,000 K confirms that this recombination reaction is governed by a nonadiabatic curve crossing with an activation barrier of about 20 kJ and subsequent deactivation of a singlet CO₂ molecule.     

Reaction of carbon monoxide with ozone: Kinetics and chemiluminescence

The reaction of carbon monoxide with ozone was studied in the range of 75–160°C in the presence of varying amounts of CO₂ and, for a few experiments, of O₂. At room temperature the reaction was immeasurably slow, but in a flow system it showed chemiluminescence with undamped oscillations. In a static system above 75°C the emission showed damped oscillations when O₂ was present. In the absence ofadded O₂ the emission showed a slow decay with a half-life of 1 hr. The luminescence consisted of partially resolved bands in the range of 325–600 nm, and the source was identified as CO₂(¹B₂) → CO₂(¹Σ_g⁺) + hv. The kinetics were complex, and the observed rate law could be accounted for bya mechanism involving the chain sequence \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm O(}^{\rm 3} P{\rm ) + CO( + M)}\mathop {{\rm rightarrow}}\limits^{\rm 3} {\rm CO}_{\rm 2} {\rm (}^{\rm 3} B_{\rm 2} {\rm ) ( + M), CO}_{\rm 2} {\rm (}^{\rm 3} B_{\rm 2} {\rm ) + O}_{\rm 3} {\rm }\mathop {{\rm rightarrow}}\limits^{\rm 7} {\rm CO}_{\rm 2} {\rm (}^{\rm 1} \sum\nolimits_{\rm g}^{\rm + } {} {\rm ) + O}_{\rm 2} {\rm + O} $\end{document}. From measurements of -d[O₃]/dtand relative emission, rate constant ratios were obtained and estimates of k₃were made.     

Formation of oxygen atoms in the reaction of chlorine atoms with ozone

Oxygen atoms are detected by NO + O + M chemiluminescence as a secondary product of the reaction between Cl and O₃. The mechanism Cl + O₃ → ClO + O₂(¹Σ⁺_g), O₂(¹Σ⁺_g) + O₃ → O₂ + O₂ + O is proposed to account for the oxygen atom formation. The branching ratio to the O₂(¹Σ⁺_g) product in the reaction of Cl with O₃ is estimated to be in the range (0.1–0.5) x 10^?2.     

Dissociation of ozone by oxygen atoms and metastable oxygen molecules

The spatial distribution of O₃ in the flow tube of an O₂ dioscharge at 0.5–3 torr was mass spectrometrically determined. Using a silver oxide surface for scavenging O and O₃, [O] and [O₂^#] were calorimetrically determined. The decay processes are discussed.     

Reaction of zirconium hydrocarbyls with carbon monoxide

Carbon monoxide reacts with tetrahydrocarbylzirconium compounds, (RCH₂)₄Zr, where R = phenyl or vinyl to give a polymeric species containing ZrOC bonds, which on hydrolysis yields products consistent with successive insertion of CO and ZrC(O)CH₂R into the ZrC bonds.     

Reaction of hydride complexes of nickel with carbon monoxide

Conclusions When the hydride complexes of nickel (Ph₃P)₃Ni(H)Br and [(Ph₃P)₃Ni(H)(CH₃CN)]⁺BF₄ ^– are reacted with CO, the Ni-H bond is cleaved and carbonyl complexes of Ni(0) are formed.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1919–1920, August, 1981.     

Organotitanium carbonyls. Reaction of tetrabenzyl-titanium with carbon monoxide

Tetrabenzyltitanium and its dicyclohexylamine adduct react with carbon monoxide to form acylbenzyltitanium compounds, which have been characterized. The presence of (PhCH₂)₄Ti(CO)₂ (amine) and (PhCH₂)₄Ti(CO) (amine) as intermediates was indicated by the IR spectra.     

Alkenoxy radicals in gas-phase reactions of alkenes with oxygen atoms or ozone

Observations in the O₃ + trans-2-butene reaction system and in the O + trans-2-butene + O₂ reaction system suggest the intermediacy of alkenoxy radicals. A mechanism is proposed for the production of C_n and C_m (m <n) alkenoxy radicals by the reaction of C_nH_2n alkenes with oxygen atoms or with ozone.     

Coadsorption of carbon monoxide and copper atoms on rhodium electroplates

The partial removal of copper atoms from a preliminarily formed Cu_ad layer and the adsorption of Cu²⁺ cations in the presence of a CO_ads monolayer were demonstrated for Rh/Pt electrodes by means of transients of current and potentiodynamic and analytical measurements. The electrooxidation of the mixed CO_ads + Cu_ad layer in the course of anodic potential scans is shown to be accompanied by simultaneous removal of both species in a wide potentials range.Translated from Elektrokhimiya, Vol. 41, No. 3, 2005, pp. 367–370.Original Russian Text Copyright © 2005 by Gladysheva, Podlovchenko.     

Vibration-vibration energy exchange between carbon monoxide and oxygen

The rates of V-V energy transfer for CO-O₂ in the temperature range 133 to 323°K were studied using a steady-state vibrational quenching technique. This work clears the discrepancy between previous available room temperature measurements, and demonstrates a linear dependence of log V-V exchange probability with log temperature.     

Stable carbon and oxygen isotopic analysis of carbon monoxide in natural waters

Techniques have been developed to allow on-line simultaneous analysis of concentration and stable isotopic compositions ((13)C and (18)O) of dissolved carbon monoxide (CO) in natural water, using continuous-flow isotope ratio mass spectrometry (CF-IRMS). The analytical system consisted sequentially of a He-sparging bottle of water, a gas dryer, CO(2)-trapping stage using both Ascarite trap and silica-gel packed gas chromatography (GC), on-line oxidation to CO(2) using the Schütze reagent, cryofocusing, GC purification using a capillary column and measurement by CF-IRMS. Each sample analysis takes about 40 minutes. The detection limit with delta(13)C standard deviation of 0.5 per thousand is 300 pmol and that with delta(18)O deviation of 1.0 per thousand is 750 pmol. Analytical blanks associated with these methods are 21+/-9 pmol. The procedures are evaluated through analyses of temporally varying concentration and isotopic compositions of CO in an artificial lake on the university campus. The delta(13)C and delta(18)O values of CO showed wide variation in accordance with diurnal variation of CO concentration, probably due to significant isotopic effects during photochemical production and microbial oxidation of CO in the aquatic environment. The delta(13)C and delta(18)O values of CO should be a useful tool in studies of the mechanism and pathways of CO production and consumption in natural waters.     

Spectral dependence of oxygen and carbon monoxide photoadsorption on rutile

Oxygen photoadsorption in the range of impurity absorption of rutile is governed by the surface hydration. The activity maximum is in the region of intrinsic absorption, where carbon monoxide is photoadsorbed.

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, . CO .

     

Reaction of o-oxazolinylphenyllithium with carbon monoxide. Carbonylative cyclization via an aroyllithium intermediate

The carbonylation of a phenyllithium containing an oxazoline group at the ortho position, followed by quenching with water, afforded a tricyclic compound, 3,3-dimethyl-2,3-dihydrooxazolo[2, 3-a]isoindol-5(9bH)-one, in 91% yield. This reaction proceeded via an intramolecular cyclization of the aroyllithium species, to give the tricyclic dienolate. Treatment of the tricyclic dienolate with electrophiles, such as alkyl halides, aldehydes, ketones, and epoxides gave the substituted oxazolo[2,3-a]isoindolinones in good yield.     

Adsorption of carbon monoxide and oxygen on Pt(110)

Adsorption of CO and O₂ on Pt(110) was studied by XPS, LEED and TDS methods to elucidate the role of O_ads states and structural rearrangements of the surface under the action of CO_ads in the appearance of self-oscillations in the rate of CO oxidation on Pt(110).

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, CO O₂ Pt(110) O CO CO Pt(110).