Photolysis of propyne at 1470 A
Atomic and molecular hydrogen yields of propyne photolysis at 1470 A Xe resonance line
De Carlo, V. J.↗
SEARCH · Search NASA
Results for “Photolysis”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Photolysis of 1,4-dichlorobutane sensitized by various aliphatic ketones
Photolysis of HCl photosensitized evolution from dichlorobutane in solution by aliphatic ketones
Golub, M. A.↗
The photolysis of CO2 at wavelengths exceeding 1740 A
Carbon dioxide photolysis at 1740-2100 A applied to photochemistry of Mars lower atmosphere
Heimerl, J. M.↗
Photolysis of CO2 at 1849 A
Carbon dioxide photolysis at 1849 A and various pressures, suggesting gas dissociation at wavelengths with appreciable absorption
Demore, W. B.↗
CO quantum yield in the photolysis of CO2 at wavelength 1470 and wavelengths 1500-1670.
The results of carbon monoxide quantum yield measurements of carbon dioxide photolysis by radiation at 1470 A and in the region from 1500 to 1670 A are presented in tabular form. The experimental technique and equipment developed by Inn and Heimerl (1971) were used. These measurements, together with some previously reported ones for a longer wavelength region, are intended to provide a uniform set of values based on the same experimental technique for the entire spectral region that is relevant to the carbon-dioxide photochemistry in the atmospheres of Mars and Venus.
Inn, E. C. Y.↗
Photolysis of O3 at 3130A
The photolysis of O3 at 3130 A and 25 C has been studied in the presence of a large excess of N2O to react with any O(1D) atoms produced. From the N2 produced, the quantum efficiency for O(1D) production was found to be 0.50 + or - 0.03.
Simonaitis, R.↗
The photolysis of CH3ONO
The photolysis of CH3ONO, alone and in the presence of NO, NO-N2 mixtures, and NO-CO mixtures was studied between 25 and 150 C. The major products are CH2O, N2O, and H2O. The quantum yields of N2O were measured. The N2O yield is large at low pressures but approaches a high-pressure limiting value of 0.055 at all temperatures as the excited CH3O produced in the primary step is stabilized by collision. In the presence of excess CO, and N2O yield drops, and CO2 is produced (though not in sufficient amounts to account for the drop in N2O). When pure CH2ONO is photolyzed, CO is produced and NO accumulates in the system. Both products are formed in related processes and result from CH3O attack on CH2O.
Wiebe, H. A.↗
O(D-1) production in ozone photolysis near 310 nm
Relative quantum yields of O(D-1)production, phi, in ozone photolysis from 275 nm to 334 nm were determined in the gas phase at 233 K. The O(D-1) was monitored by means of its reaction with isobutane to form isobutyl alcohol. The light source was a high pressure mercury lamp combined with a monochromator, with a bandwidth of 1.6 nm. The results show a constant phi below 300 nm, which is taken as unity on the basis of previous work. There is a very sharp fall-off in phi which is centered at 308 nm. At 313 nm phi is not greater than 0.1.
Lin, C.↗
Photolysis of methyl nitrite.
Study of the photolysis of CH3ONO, alone and in the presence of NO, NO-N2 mixtures, and NO-CO mixtures, between 25 and 150 F. The major products of this reaction are CH2O, N2O, and H2O. The steps responsible for these products are determined. The N2O yield is large at low pressures but approaches a high-pressure limiting value of 0.055 at all temperatures as the excited CH3O produced in the primary step is stabilized by collision. Nitrogen is also a product of the reaction and is produced from two sources. When pure CH3ONO is photolyzed, CO is produced and NO accumulates in the system. Both products are formed in related processes and result from CH3O attack on CH2O.
Wiebe, H. A.↗
Ammonia photolysis on Jupiter.
Ammonia photolysis under simulated Jovian conditions indicates that the photochemical reaction would rapidly convert all the ammonia of Jupiter to nitrogen even in a large excess of hydrogen. It is suggested that ammonia is observed because the planet's atmosphere is deep and hot and/or because electrical discharge phenomena are important.
Nicodem, D. E.↗
Photolysis of spacecraft contaminants
A molecular beam facility, which was designed to measure photochemical cross-sections, has been constructed at the Athens College science facility. The integration of this vacuum system into an operational photochemical instrument was performed with signal processing consisting of both dc and ac techniques. Of the experiments performed to date on the vacuum ultraviolet photolysis of water vapor, it is apparent that a larger pumping capacity (preferably with differential pumping) is required to improve upon the background signal. Both phase-sensitive detection and ion-counting techniques are recommended for future studies.
Workman, G. L.↗
A flash photolysis-resonance fluorescence kinetics study of the reaction S/3P/ + OCS
Using the technique of flash photolysis-resonance fluorescence, the reaction of ground-state atomic sulfur with carbonyl sulfide has been investigated over the temperature range from 233 to 445 K. Over this temperature range, the experimental data were fitted to an Arrhenius equation of the form k sub 1 = (1.52 plus or minus 0.20) x 10 to the minus 12th power exp(-3.63 plus or minus 0.12 kcal/mol/RT) cu cm/molecule/sec. A comparison of these results with previous investigations on this reaction system is presented.
Klemm, R. B.↗
O/1 D/ production in ozone photolysis near 3100 A
Relative quantum yields of O(1 D) production in ozone photolysis from 2750 to 3340 A have been determined in the gas phase at -40 C. The O(1 D) was monitored by means of its reaction with isobutane to form isobutyl alcohol. The light source was a high pressure mercury lamp combined with a monochromator, with a bandwidth of 16 A. The results show a constant O(1 D) production below 3000 A, which is taken as unity on the basis of previous work. There is a very sharp fall-off in O(1 D) production which is centered at 3080 A. At 3130 A, O(1 D) production is not greater than 0.1.
Lin, C.-L.↗
On disequilibrated rotational distributions of CN/X/ produced in the photolysis of ClCN
The rotational-vibrational product state distributions of the CN(X 2Sigma (+)) radicals which are produced in photolysis at a wavelength of about 160 nm were monitored by laser-induced fluorescence detection. A nitrogen laser pumped dye laser was used to excite the violet band fluorescence of CN. The number of collisions the radicals undergo between formation and detection was controlled by the total pressure and the time delay between the flash lamp pulse and the laser pulse. An argon flash lamp with a Suprasil transmission window was used to dissociate the ClCN. Disequilibrated rotational distributions of CN(X) are displayed, the spectrum showing that the nu = 0 and 1 levels are rotationally hot. The rotational distributions of CN(X 2 Sigma (+), nu = 0) are shown as a function of collision number. At a pressure of 0.070 torr and a delay of 2.0 microsecs, the distribution shows clearly that the excited rotational levels peak near N equals 66-70.
Sabety-Dzvonik, M.↗
Solar photolysis of water
Hydrogen is produced by the solar photolysis of water in a first photooxidation vessel with a transparent wall in the presence of a water soluble photooxidizable reagent and an insoluble hydrogen recombination catalyst. Simultaneously oxygen is produced in a second photoreduction reactor with a transparent wall in the presence of an insoluble photoreduction reagent catalyst. When spent, the solution from the first reactor is fed into the second reactor. A reaction occurs in the dark in which the redox reagents are regenerated, and the regenerated photooxidation reagent solution is recycled to the first reactor. The photoreduction-catalyst is a bifunctional reagent catalyst including a transition metal salt together with a hydroxyl or chlorohydroxyl decomposition catalyst of high area.
Ryason, P. R.↗
Laser-induced fluorescence of CN/X2 Sigma +/ produced by photolysis of C2N2 at 160 nm
The paper reports laser-induced fluorescence measurements of the initial product state distributions of CN(X2 Sigma +) produced during the photolysis of C2N2 at a wavelength of 160 nm. The parent molecules were photodissociated by an argon flash lamp, and saturated solutions of BBD in p-dioxane were used as a laser dye to produce radiation that excited CN radicals in the (upsilon-double-prime, N-prime) vibrational-rotational sublevels of the X state to the B-state sublevels. Spectral-line identification is discussed along with the observed rotational, electronic, and vibrational energy partitionings. The effect of added buffer gas (N2 or He) on the observed product state distributions is examined in order to monitor collisional energy transfer from CN(A2 Pi, upsilon = 0) to CN(X2 Sigma +, upsilon-double-prime = 4). It is found that both buffer gases produce population inversion between the upsilon-double-prime = 4 and upsilon-double-prime = 3 levels of the X state.
Cody, R. J.↗
Hydrogen quantum yields in the 360 nm photolysis of Eu/2+/ solutions and their relationship to photochemical fuel formation
Water decomposition by a cyclic photoredox process is discussed in general terms. Thermodynamics determines the wavelength of the charge-transfer band corresponding to electron transfer to or from water of hydration of a cation. These relationships indicate that it is unlikely that a photoreduction reaction resulting in water decomposition will occur in the sea-level solar range of wavelengths. Such is not the case for photooxidation, and an example is known: the photolysis of Eu(2+) in aqueous solution. Hydrogen quantum yields have been determined for this reaction. They are sufficiently high (about 0.3) as to offer encourangement for the further exploration of photoredox reactions as a means of solar energy conversion.
Ryason, P. R.↗
Flash photolysis resonance fluorescence investigation of the reaction of Cl/2P/ atoms with ClONO2
Rate constants for the removal of Cl(2P) atoms by homogeneous gas phase reaction with ClONO2 were measured using the flash photolysis resonance fluorescence technique at 224, 250, and 273 K. The values obtained have been used to derive the above Arrhenius equation. The uncertainties expressed are 95% confidence limits obtained using the statistical standard deviation of the individual rate constants plus a 15% additional estimated uncertainty attributed to difficulties in chlorine nitrate concentration measurements. The results indicate that destruction of chlorine nitrate by reaction with chlorine atoms is perhaps the least important of the atmospheric reactive channels, and is at least three orders of magnitude slower than calculated photodissociation rates at all stratospheric altitudes.
Kurylo, M. J.↗