| Impulse Pendulum with Adjustable Pivot Point for Measuring Coupling Coefficient |
OCT 2004 |
8 pages |
| Authors:
John S. Harchanko; Franklin B. Mead Jr.; C. W. Larson; AIR FORCE RESEARCH LAB EDWARDS AFB CA SPACE AND MISSILE PROPULSION DIV
|
 | An impulse pendulum with significantly increased sensitivity compared to its predecessor is described. The problems associated with its predecessor are discussed and other pendulum designs are also presented. The design approach for the new pendulum is then presented along with the current mechanical design and photographs of the finished pendulum. The pendulum's performance is presented compared to its predecessor. Finally, other embodiments of the approach are presented. |
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| Absorption Enhanced Liquid Ablation with TEA CO2 Laser |
OCT 2004 |
8 pages |
| Authors:
Enrique Sterling; Andrew V. Pakhomov; C. W. Larson; Franklin B. Mead Jr; ALABAMA UNIV IN HUNTSVILLE
|
| A novel technique for measuring of force as a function of time was developed for the study of enhanced momentum transfer in laser-ablated water solutions of Sodium Tetrafluoroborate NaBF4, a compound that strongly absorbs radiation in the 8-11 m wavelength interval. A TEA CO2 laser (λ = 10.6 m), 300 ns pulse width and 8 J pulse energy, was used for ablation of water diluted NaBF4 contained in a conical ... |
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| Benefit of Constant Momentum Propulsion for Large Delta V Missions - Applications to Laser Propulsion |
JAN 2004 |
21 pages |
| Authors:
C. W. Larson; Franklin B. Mead Jr; Sean D. Knecht; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE
|
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| Launching of Micro-Satellites Using Ground-Based High Power Pulsed Lasers |
OCT 2003 |
45 pages |
| Authors:
V. Hasson; F. B. Mead Jr.; C. W. Larson; ENGINEERING RESEARCH AND CONSULTING INC(ERC INC) EDWARDS AFB CA
|
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| Thermodynamic Limitations on Energy Conversion in Laser Propulsion |
21 AUG 2003 |
12 pages |
| Authors:
C. W. Larson; F. B. Mead Jr.; S. D. Knecht; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE
|
| We show that perfect propulsion requires a constant momentum mission, as a consequence of Newton's second law. Perfect propulsion occurs when the velocity of the propelled mass in the inertial frame of reference matches the velocity of the propellant jet in the rocket frame of reference. We compare constant momentum to constant specific impulse propulsion, which, for a given specification of the mission delta V, has an optimum specific impulse ... |
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| Thermodynamic Limitations on Energy Conversion in Laser Propulsion |
21 AUG 2003 |
24 pages |
| Authors:
C. W. Larson; F. B. Mead Jr.; S. D. Knecht; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE
|
| Outline: Comparison of Constant Momentum Mission and Constant Specific Impulse Mission; Efficiency of conversion of laser energy to propellant kinetic energy; Upper limit to conversion of laser energy to jet kinetic energy from energy conservation and definitions; Comparing momentum quantities to energy quantities. The "Phi Factor" and velocity distributions in propellant jet. Phi values for delta function, Maxwellian, Gaussian, Chunks and gas, supersonic expansion, etc.; Upper limits to performance based ... |
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| Isolation of Boron and Carbon Atoms in Cryogenic Solids |
21 AUG 2003 |
15 pages |
| Authors:
C. W. Larson; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE
|
| Outline: Theoretical Isp of cryogenic solid propellants composed of the atoms, dimers and trimers of lightweight elements isolated in solid para hydrogen. Consequences of condensation; Spectroscopic studies of Boron/Carbon clusters by matrix isolation spectroscopy; Development of stable, hi-flux boron atom source for preparation of cryogenic solid HEDM (under auspices of Small Business Innovative Research (SBIR) program; First optical spectrum of B3 (under auspices of International Research Initiative of the Air ... |
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| Isolation of Boron and Carbon Atoms in Cryogenic Solids |
13 AUG 2003 |
9 pages |
| Authors:
C. W. Larson; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE
|
| Boron and carbon atoms, and their dimmers and trimers were isolated in solid argon by co-condensation of their vapors onto a substrate maintained at 10 K. Growth and disappearance of various clusters with 3 to 12 atoms that occurred during annealing was studied by quantitative Fourier Transform Infrared Spectroscopy. The annealing experiments indicated that the initially formed solids contained about 80% B and C atoms and BC molecules. At 5 ... |
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| Laser Propulsion and the Constant Momentum Mission |
2003 |
13 pages |
| Authors:
C. W. Larson; Franklin B. Mead Jr.; Sean D. Knecht; AIR FORCE RESEARCH LAB EDWARDS AFB CA SPACE AND MISSILE PROPULSION DIV
|
| We show that perfect propulsion requires a constant momentum mission, as a consequence of Newton's second law. Perfect propulsion occurs when the velocity of the propelled mass in the inertial frame of reference matches the velocity of the propellant jet. in the rocket frame of reference. We compare constant momentum to constant specific impulse propulsion, which, for a given specification of the mission delta V' has an optimum specific impulse ... |
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| Comparative Lightcraft Impulse Measurements |
13 MAR 2002 |
13 pages |
| Authors:
F. B. Mead Jr.; C. W. Larson; W. M. Kalliomaa; W. O. Schall; H. A. Eckel; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE WEST
|
| The impulse coupling coefficients of two radically different laser propulsion thruster concepts (lightcrafts), each 10 cm in diameter, have been measured under equal conditions using two different pendulum test stands. One test stand and one lightcraft of toroidal shape were provided by the U.S. Air Force Research Laboratory. The other test stand and a bell shaped (i.e. a paraboloid) lightcraft were those of the German Aerospace Center (DLR). All experiments ... |
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| Energy Conversion in Laser Propulsion III |
FEB 2002 |
15 pages |
| Authors:
C. W. Larson; F. B. Mead Jr.; Wayne M. Kalliomaa; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE WEST
|
| Conversion of pulses of CO2 laser energy (18 microsecond pulses) to propellant kinetic energy was studied in a Myrabo Laser Lightcraft (MLL) operating with laser heated STP air and laser ablated delrin propellants. The MLL incorporates an inverted parabolic reflector that focuses laser energy into a toroidal volume where it is absorbed by a unit of propellant mass that is subsequently expanded in the geometry of the plug nozzle aerospike. ... |
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| Energy Conversion in Laser Propulsion II |
26 DEC 2001 |
22 pages |
| Authors:
C. W. Larson; Franklin B. Mead Jr.; Wayne M. Kalliomaa; AIR FORCE RESEARCH LAB EDWARDS AFB CA SPACE AND MISSILE PROPULSION DIV
|
| This paper reports on an analysis of overall energy conversion in laser propulsion. Experimental studies of a laboratory-scale propulsion device that absorbs laser energy and converts that energy to propellant kinetic energy were carried out. The Myrabo Laser Lightcraft (MLL), propelled by laser-heated air, was studied. The MLL incorporates an inverted parabolic reflector that focuses laser energy into a toroidal volume where it is absorbed by a unit of propellant ... |
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| Comparative Lightcraft Impulse Measurements |
19 NOV 2001 |
4 pages |
| Authors:
Franklin B. Mead Jr.; C. W. Larson; Wayne M. Kalliomaa; AIR FORCE RESEARCH LAB EDWARDS AFB CA SPACE AND MISSILE PROPULSION DIV
|
| The impulse coupling coefficients, cm, of two radically different laser propulsion thruster concepts (lightcrafts), each 10 cm in diameter, have been measured under equal conditions using two different test stands. Lightcraft one is of toroidal shape and was provided by the U.S. Air Force Research Laboratory (AFRL). A lightcraft of this shape and size has been used in free flight experiments at White Sands Missile Range, NM. Lightcraft two is ... |
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| A Status Report of the X-50LR Program. A Laser Propulsion Program |
01 OCT 2001 |
4 pages |
| Authors:
Frank B. Mead Jr.; C. W. Larson; Wayne M. Kalliomaa; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE WEST
|
| In 1996, the Air Force Research Lab's Propulsion Division at Edwards AFB initiated a program that had as its main objective to launch a laser- propelled vehicle into a suborbital trajectory within a period of 5 years in order to demonstrate the concept and its attractive features. The concept was to be a nanosatellite in which the laser propulsion engine and satellite hardware were intimately shared. This concept was based ... |
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| Laser-Powered, Vertical Flight Experiments at the High Energy Laser System Test Facility |
02 JUL 2001 |
19 pages |
| Authors:
Franklin B. Mead Jr.; C. W. Larson; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE WEST
|
| In 1996. the Air Force Research Laboratory's Propulsion Division at Edwards AFB initiated the Lightcraft Technology Demonstration (LTD) Program that had as its main objective to launch a laser-propelled vehicle into a suborbital trajectory within a period of 5 years. The concept is a nanosatellite in which the laser propulsion engine and satellite hardware are intimately shared. |
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| Energy Conversion in Laser Propulsion |
JAN 2001 |
23 pages |
| Authors:
C. W. Larson; F. B. Mead Jr; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE WEST
|
| Analysis of energy conversion in laser propulsion is reported and compared to experimental studies of a laboratory scale propulsion device that absorbs laser energy and converts that energy to propellant kinetic energy. The propellants studied were air and Delrin, a solid with the composition of formaldehyde H2CO that vaporizes cleanly upon laser irradiation. The Myrabo Laser Lightcraft (MLL) was studied. It incorporates an inverted parabolic reflector that focuses laser energy ... |
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| Laser-Powered, Vertical Flight Experiments at the High Energy Laser System Test Facility |
13 NOV 2000 |
4 pages |
| Authors:
Franklin B. Mead Jr.; C. W. Larson; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE WEST
|
| In 1996, the Air Force Research Laboratory's Propulsion Division at Edwards AFB initiated a program that had as its main objective to launch a laser-propelled vehicle into a suborbital trajectory within a period of 5 years in order to demonstrate the concept and its attractive features. The concept is a nanosatellite in which the laser propulsion engine and satellite hardware are intimately shared. The Lightcraft Technology Demonstration Program was planned ... |
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| Review of Recent Progress During Laser-Powered Lightcraft Flights to Unlimited Altitudes |
26 SEP 2000 |
3 pages |
| Authors:
Franklin B. Mead; C. W. Larson; AIR FORCE RESEARCH LAB EDWARDS AFB CA SPACE AND MISSILE PROPULSION DIV
|
| In 1996, the Air Force Research Laboratory's Propulsion Division at Edwards AFB initiated a project that had as its main objective to launch a laser-propelled Lightcraft into a suborbital trajectory within a period of five years in order to demonstrate the concept and its attractive features. The Lightcraft concept is a nanosatellite in which the laser propulsion engine and satellite hardware are intimately shared. The forebody aeroshell acts as an ... |
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| Matrix Isolation of Boron and Carbon Vapor. Control of Cluster Formation During Preparation and Annealing |
15 MAR 2000 |
10 pages |
| Authors:
C. W. Larson; J. Harper; J. D. Presilla-Marquez; AIR FORCE RESEARCH LAB EDWARDS AFB CA SPACE AND MISSILE PROPULSION DIV
|
| The formation and recombination of small boron/carbon clusters were studied by quantitative Fourier transform infrared (FTIR) spectroscopy. Samples were prepared by evaporation of powder mixtures from a resistively heated oven (3000 K) and isolated at 10 K in solid argon C3 and BC2 disappeared entirely over the course of several annealings. Yields of all the larger clusters (BiCnj, II> 4 J = 0, 1, 2) increased during annealing. Clusters within ... |
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| Matrix Isolation of Boron and Carbon Vapor. Control of Cluster Formation during Preparation and Annealing |
15 MAR 2000 |
18 pages |
| Authors:
J. D. Presilla-Marquez; J. Harper; C. W. Larson; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE WEST
|
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| Kinetics of Formation of Cyclic C6 and Cyclic C8 and BJCn-J Clusters (J=0, 1, 2; n = 3-11) in Solid Argon |
24 JUN 1999 |
19 pages |
| Authors:
J. D. Presilla-Marquez; J. Harper; C. W. Larson; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE WEST
|
| Graphs featuring the kinetics of formation of cyclic C6 and C8 and BjCn-j clusters. |
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| Identification and Condensation of Cyclic C6 and Cyclic C8 in Solid Argon Characterization of Matrix Isolated BjCn-j J=0, 1, 2,: n=3-11 in Solid Argon |
08 JUN 1999 |
30 pages |
| Authors:
C. W. Larson; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE WEST
|
| Graphs of identification and condensation of cyclic C6 and cyclic C8 in solid argon, and the characterization of matrix isolated BjCn-j in solid argon. |
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| Promising Thermal Source of Boron Atoms |
02 JUN 1999 |
19 pages |
| Authors:
J. Harper; C. W. Larson; AIR FORCE RESEARCH LAB EDWARDS AFB CA SPACE AND MISSILE PROPULSION DIV
|
| A "cannon" design has been tested as a high flux thermal source of pure boron atoms. Boron is packed into a central channel of a 1/4 in graphite rod with the open end pointed towards the deposition substrate. A refractory metal sheath surrounds and heats the carbon as the applied current increases. Successful argon matrix isolation experiments indicate that the boron cannon will be an effective way to produce pure ... |
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| Kinetics of Boron Carbon HEDM |
28 MAY 1999 |
16 pages |
| Authors:
C. W. Larson; AIR FORCE RESEARCH LAB EDWARDS AFB CA SPACE AND MISSILE PROPULSION DIV
|
| The objective of this research is the development and characterization of a boron atom source. |
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| Vibrational Spectra of Linear BC3 and Linear B2C2 in Argon at 10K(a) |
16 NOV 1998 |
25 pages |
| Authors:
Jose D. Presilla-Marquez; Patrick G. Carrick; C. W. Larson; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE WEST
|
| The vibrational spectra of linear BC3 and linear B2C2 in an argon matrix at 10 K have been observed for the first time by Fourier transform infrared spectroscopy. Mixtures of boron and carbon powders were vaporized in a resistively heated (^3000 K) oven. BC3 was produced during co-deposition of the vapors with argon onto a CsI substrate maintained at 10 K; B2C2 was observed only after annealing the matrices. Frequencies ... |
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| Vibrational Spectra of Cyclic C8 in Solid Argon |
20 OCT 1998 |
17 pages |
| Authors:
Jose D. Presilla-Marquez; Jessica Harper; Jeffrey A. Sheehy; Patrick G. Carrick; C. W. Larson; SCHAFER CORP CALABASAS CA
|
| Vapors from solid and powdered carbon, emitted from an oven cycled between 2000 and 3000 K, were co-condensed with argon onto a CsI substrate maintained at 10 K. The cycling process produced a multilayered matrix with regions of high carbon density alternating with layers of argon. FTIR measurements including complete 13C isotopic data, supported by ab initio calculations, allow the assignment of a band observed at 1817.8 cm(-1) to the ... |
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| Quantitative Analysis of the Condensation of BjCn-j Clusters (n = 2-12, J = 0,1,2) in Solid Argon |
22 MAY 1998 |
15 pages |
| Authors:
J. Harper; J. A. Sheehy; J. D. Mills; C. W. Larson; AIR FORCE RESEARCH LAB EDWARDS AFB CA SPACE AND MISSILE PROPULSION DIV
|
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| Isolation of Carbon Atoms in Cryogenic Solids |
30 APR 1998 |
15 pages |
| Authors:
J. Harper; J. A. Sheehy; C. W. Larson; AIR FORCE RESEARCH LAB EDWARDS AFB CA SPACE AND MISSILE PROPULSION DIV
|
| Briefing notes and graphs featuring research on the isolation of carbon atoms in cryogenic solids presented at the AFOSR HEDM Contractor's Conference, held in Monterey, CA, 20-22 May 1998. |
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| Solar Plasma Physics |
MAR 97 |
8 pages |
| Authors:
C. W. Larson; PHILLIPS LAB EDWARDS AFB CA
|
| This final report provides a historical perspective and a summary of the productivity of this project. Twenty-one publications were produced during the 10-year period 1986 to 1996 as conference proceedings, technical reports, Ph.D dissertations and referred papers. The objective of the project was to measure the optical absorptivities in the visible region of the spectrum of alkali metal vapors in hydrogen gas to support the design of a solar powered ... |
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| Characterization of Cryogenic Solid Hybrid Rocket Motors |
DEC 95 |
|
| Authors:
Patrick G. Carrick; C. W. Larson; Kevin L. Pfeil; PHILLIPS LAB EDWARDS AFB CA
|
 | The study of the combustion of cryogenic (77K) solid hydrocarbons in a laboratory scale tube burner that approximates the geometry of the hybrid rocket was extended. This work was carried out to demonstrate the feasibility of cryogenic fuel combustion in the hybrid rocket geometry and to extend knowledge about hybrid rockets to fuels that have very high regression rates as a consequence of their high mass transfer number, or blowing ... |
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| Solar Plasma Propulsion |
MAR 87 |
|
| Authors:
C. W. Larson; DAYTON UNIV OH RESEARCH INST
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| The simultaneous measurement of absorption and emission spectroscopy is proposed to enable quantitative determination of the performance of a gaseous plasma solar energy receiver. Production of an experimental spectroscopy data base of species composed of hydrogen and selected Group 1 elements (the alkali metals) and Row 2 elements (carbon, nitrogen, and oxygen) approaching conditions heretofore unattained in a static gas spectrometer cell, 3000 K and 100 atmospheres, is the principal ... |
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| Identity Scrambling and Isomerization Networks in Systems of Excited Alkyl Radicals. |
30 MAR 1972 |
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| Authors:
B. S. Rabinovitch; C. W. Larson; P. T. Chua; WASHINGTON UNIV SEATTLE DEPT OF CHEMISTRY
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| The gas phase isomerization by H-atom transfer of vibrationally excited alkyl radicals of general structure G-C-C(-C)-C(.)-C has been studied; G G was an H, methyl, ethyl, iso-propyl or tert-butyl group. The radicals were produced by chemical activation by the addition of an H-atom to an appropriate alpha-olefin. The study expands on earlier findings and shows that alkyl radicals, vibrationally excited above 40 kcal/mole, are involved in a characteristic process of ... |
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| Disproportionation-Recombination Ratios of Large Branched Alkyl Radicals. |
30 DEC 1970 |
|
| Authors:
J. H. Georgakakos; B. S. Rabinovitch; C. W. Larson; WASHINGTON UNIV SEATTLE DEPT OF CHEMISTRY
|
| The study of the disproportionation of alkyl radicals has been extended to large branched pentyl-2 radicals. Contrary to the belief based on small radical behavior, steric and activation energy effects are shown to be important. Existing data in the literature are summarized from the point of view of entropy effects. (Author) |
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| COMPETITIVE UNIMOLECULAR DECOMPOSITION OF ALKYL RADICALS. TERTIARY BUTYL RUPTURE. |
15 JAN 1970 |
|
| Authors:
C. W. Larson; B. S. Rabinovitch; WASHINGTON UNIV SEATTLE DEPT OF CHEMISTRY; WASHINGTON UNIV SEATTLE DEPT OF CHEMISTRY
|
| The competitive unimolecular decomposition of vibrationally excited 3,4,4-trimethylpentyl-2 radical was investigated. Relative and absolute rate of decomposition by tert-butyl (tBu) and methyl (Me) radical rupture were measured. Results were interpreted in terms of the Rice-Ramsperger-Kassel-Marcus (RRKM) unimolecular rate theory and lead to a value for the dissociation energy of (tBu-H) as 89.0 kcal/mole. Activation energies at 0K for tBu and Me radical addition to olefins are discussed; ... |
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| ISOMERIZATION OF VIBRATIONALLY EXCITED ALKYL RADICALS BY H-ATOM MIGRATION. |
01 NOV 1969 |
|
| Authors:
E. A. Hardwidge; C. W. Larson; B. S. Rabinovitch; WASHINGTON UNIV SEATTLE DEPT OF CHEMISTRY; WASHINGTON UNIV SEATTLE DEPT OF CHEMISTRY
|
| The intramolecular isomerization by H-atom transfer, of ten vibrationally excited alkyl radicals was investigated. A chemical activation technique was used to produce the excited alkyl radicals in energy states near 45 kcal/mole. Reactions which proceed via a 6-membered ring transition state are most labile; a table of relative isomerization tendency as a function of ring size and H-type is given. (Author) |
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| COMPETITIVE UNIMOLECULAR DECOMPOSITION IN CHEMICALLY ACTIVATED RADICAL SYSTEMS. ISOPROPYL RADICAL RUPTURE. |
01 NOV 1968 |
|
| Authors:
B. S. Rabinovitch; C. W. Larson; WASHINGTON UNIV SEATTLE DEPT OF CHEMISTRY
|
| Detailed study has been made of the competitive unimolecular decomposition of several chemically activated radicals: 2-methyl hexyl-3, 4-dimethyl pentyl-2 and 5-methyl hexyl-3. These decompose by C-C bond ruptures to give isopropyl and methyl radicals. Disproportionation-recombination ratios of the various radicals were measured. The value of D(Iso-Pr-H) is determined to be 12.7 kcal/mole. The rate data are examined on a theoretical model. A summary of bond dissociation values determined by the ... |
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| COMPETITIVE UNIMOLECULAR DECOMPOSITION PROCESSES IN CHEMICALLY ACTIVATED SYSTEMS. 3-HEXYL RADICAL. |
05 JUN 1966 |
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| Authors:
D. C. Tardy; B. S. Rabinovitch; C. W. Larson; WASHINGTON UNIV SEATTLE DEPT OF CHEMISTRY
|
| A general formulation of the rates of competitive unimolecular reactions is given and various relationships between the rates, and between the energetics, of competing processes are described. The relative and absolute rates of decomposition, C-C-C-C.-C-C* to .CH3+C5H10-1 to .C2H5 + C4H8-1, were measured at pressures from 0.004 to 90 mm Hg for vibrationally excited 3-hexyl radicals, chemically activated by the addition of hydrogen atoms to trans-3-hexene at 300C. Use of ... |
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