Ramsperger studies

IC1 (g). McMorris and Yost1 studied the equilibrium, l Cl2 (g) + I2 (g)=ICl (g), at various temperatures, and deduced, for IC1 (g), Qf=— 3.13. The energy of dissociation of IC1 (g) into normal iodine and chlorine atoms has been determined from spectroscopic data by Wilson,3 Gibson and Ramsperger,1 Patkowski and Curtis,1 and Brown and Gibson.1 The data of Brown and Gibson1 are the most accurate and give, for IC1 (g), Qf= —3.46. 

Rabinovitch et al. (85) studied the reaction of H atoms with trans-ethylene-d2 as a function of ethylene pressure in the temperature range — 78 to 160°C. They were able to account for all secondary reactions of the hot ethyl radicals and to determine the rates of their decomposition (relative to stablization). Simultaneously they calculated the theoretical rates on the basis of the Rice-Ramsperger-Kassel theory of uni-molecular reactions, using expressions derived by Marcus (71), and found a reasonable agreement with the experimental values. Similar satisfactory agreements had been found previously by Rabinovitch and Die-sen (84) for hot sec-butyl radicals. Extensive studies of hot radicals produced by H or D atom additions to various olefins have been carried... 

HCOOH (g), (HCOOH)2 (g). Ramsperger and Porter2 and Coo-lidge1 studied the equilibrium, (HCOOH) 2 (g) =2HCOOH (g), and their data yield —14.13 for the heat of this reaction. The equilibrium concentrations in mole fraction are, for (HCOOH) 2 (g) and HCOOH (g), respectively, about 0.80 and 0.20 at 18°, and about 0.52 and 0.48 at the boiling point, 100.8°. Data on the heat of vaporization of liquid formic acid to form the equilibrium mixture of (HCOOH) 2 (g) and HCOOH (g)... 

The thermolysis of methylazide was studied first by Ramsperger 21a> who found it to be a homogenous first-order reaction. Studies of thermolyses of several other organic azides in various solvents and at different concentrations also show first-order kinetics 22-28). This led to the conclusion that free nitrene intermediates are involved. There are however thermal decompositions of azides where nitrene intermediates are not involved. For example ortho-substituted arylazides like o-nitrophenylazide 2, undergo formation of benzofurazan 3 by a concerted mechanism according to l.c.21b). 

Aat °(SF4)/4. Bott ( ) has reported the results of shock-tube experiments on the dissociation of SF over the temperature range 1650-1950 K. Rate constants based on spectroscopic measurements were correlated with the Rice-Ramsperger-Kassel (RRK) theory. This study strongly suggests that D (SFg-F) = 79.0+3.0 kcal mol . ... 

The most accepted modern activation theory for the outer electron transfer is that of Rudolph A. Marcus (Nobel Prize in Chemistry in 1992) [14], which is different from the transition state theory. His studies on unimolecular reactions and the transition and collision theories committed him to elaborate on the Rice-Ramsperger-Kassel-Marcus (RRKM) theory in 1952. This theory is an extension of the previous RRK theory proposed by Rice, Ramsperger, and Kassel between 1927 and 1928. Moreover, Hush and Marcus further extended the electron transfer theory of Marcus for inner electron transfers [15-17]. 

The kinetic parameters of each path are determined as a function of temperature and pressure using the bimolecular chemical activation analysis. High Pressure limit kinetic parameters from the calculation results are obtained with the canonical Transition State Theory. The multifrequency Quantum Rice-Ramsperger-Kassel analysis is utilized to obtain k(E) and Master Equation analysis is used for the evaluation of pressure fall-off in this complex bimolecular chemical activation reaction. Results are applicable to elementary experiments at low pressures, ambient combustion studies at one atmosphere, as well as higher-pressure turbine systems. 

Transition state theory (TST) and Rice-Ramsperger-Kassel-Marcus (RRKM) theory are the theories most widely used to calculate the rate constant. TST is used to study bimolecular reactions and RRKM theory is the generalization of TST which is applicable for unimolecular reactions. 

Losada, M. and Chaudhuri, S. (2010) Finite size effects on alutninum/Teflon reaction channels under combustive environment a Rice-Ramsperger-Kassel-Marcus and transition state study of fluorination. J. Chem. Phys.,... 

Single-pulse shock tube studies of the thermal dehydrochlorination reactions of chlorocyclopentane and chlorocyclohexane at temperatures of 843-1021 K and pressures of 1.4-2.4 bar have been carried out using the comparative rate technique. Absolute rate constants provided a self-consistent temperature scale of use in comparison with chemical systems studied with different temperature standards. Quantum chemical methods have been used to compute the structure and energies of reactants, products, and transition states. The computations were used, in conjunction with experimentally determined rate constants, to develop Rice-Ramsperger-Kassel-Marcus (RRKM)/ Master Equation models and thereby allow extrapolation of the experimental data over an extended range of temperatures. 

---