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Polanyi, J. C.

Publications and source records attributed to Polanyi, J. C..

15 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Reaction dynamics and the interstellar environment

Following a brief outline of the 'normal' equilibrium reaction rate laws, the theme of thermal disequilibrium in interstellar space and the related topic of detailed rate constants are more extensively discussed. Comment is made concerning the two principal techniques that are currently being used to explore the dynamical details of an increasing range of chemical reactions in the laboratory, since it is considered that these techniques suggest ways in which the understanding of the chemistry of interstellar space may be extended.

Polanyi, J. C.↗
NASA NTRS1972

Energy distribution among reaction products. VII - H + F2.

The 'arrested relaxation' variant of the IR chemiluminescence technique is used in a study of the distribution of vibrational, rotational and translational energies between the products of the reaction by which H + F2 yields HF + F. Diagrams are plotted and numerical values are obtained for the energy distribution rate constants.

Polanyi, J. C.↗
NASA NTRS1972

Energy distribution among reaction products. IV.

Use of an infrared chemiluminescence technique, called 'Method II,' or the 'method of arrested relaxation' to measure the distribution of energy among products of the Cl + HI and Cl + DI reactions. Preliminary results are also given for the Br + HI and Cl + HBr reactions. Instead of measuring vibrational relaxation, Method II attempts to arrest vibrational and rotational relaxation by the rapid removal of excited products at a cold surface.

Maylotte, D. H.↗
NASA NTRS1972

Energy distribution among reaction products. V.

Discussion of three reactions, one point of theoretical interest being the predicted correlation between barrier height and barrier location. The H + Br 2 reaction having a lower activation barrier than H + Cl 2, should have an earlier barrier, and hence a greater percentage attractive energy release and higher efficiency of vibrational excitation. Information is developed concerning the effect of isotopic substitution in the pair of reactions H + Cl 2 and D + Cl 2. The 'arrested relaxation' method was used. Essentially, the method involves reacting two diffuse reagent beams in a reaction vessel with background pressure less than 0.001 torr, and with walls cooled by liquid nitrogen or liquid helium.

Anlauf, K. G.↗
NASA NTRS1972

Energy distribution among reaction products. VI - F + H2, D2.

Study of the F + H2 reaction, which is of special theoretical interest since it is one of the simplest examples of an exothermic chemical reaction. The FH2 system involves only 11 electrons, and the computation of a potential-energy hypersurface to chemical accuracy may now be within the reach of ab initio calculations. The 'arrested relaxation' variant of the infrared chemiluminescence method is used to obtain the initial vibrational, rotational and translational energy distributions in the products of exothermic reactions.

Polanyi, J. C.↗
NASA NTRS1972

Mechanism of rotational relaxation.

A model is presented which describes the characteristic pattern of relaxation of a nonthermal rotational distribution of hydrogen halide, peaked initially at high rotational quantum number J, to a thermal distribution without generating a peak at intermediate J. A method for correcting infrared chemiluminiscence data for modest rotational relaxation is also suggested.

Polanyi, J. C.↗
NASA NTRS1971

Location of energy barriers. IV - Effect of rotation and mass on the dynamics of reactions A + BC.

Examination of the effect of the inclusion of a small but significant amount of rotational energy in the reagents, and of a change in reagent masses in a previous study of the effect of barrier location on the dynamics of thermonuclear reaction A + BC yields AB + C. The qualitative generalizations introduced in the previous study are found to remain valid despite the introduction of the variables. Of these generalizations the most important is that reagent translational energy favors reaction on surface I, whereas reagent vibration is the most favorable to reaction on surface II.

Hodgson, B. A.↗
NASA NTRS1971

Nonequilibrium processes

Nonequilibrium processes, discussing chemical reactions between electronically, vibrationally, rotationally and translationally excited reagents

Polanyi, J. C.↗
NASA NTRS1971

The molecular dynamics of atmospheric reaction

Detailed information about the chemistry of the upper atmosphere took the form of quantitative data concerning the rate of reaction into specified states of product vibration, rotation and translation for exothermic reaction, as well as concerning the rate of reaction from specified states of reagent vibration, rotation and translation for endothermic reaction. The techniques used were variants on the infrared chemiluminescence method. Emphasis was placed on reactions that formed, and that removed, vibrationally-excited hydroxyl radicals. Fundamental studies were also performed on exothermic reactions involving hydrogen halides.

Polanyi, J. C.↗