- Radical Processes in Organic Crystals Induced by Shear Deformation under Pressure
-
EPR technique is used to study the kinetics of radical generation and decay in an organic polycrystalline compound placed directly in the cavity of a modified spectrometer and subjected to shear strain under high pressure (up to 1.2 GPa).Radicals were generated by mechanically stimulated dissociation of arylindanedione dimer molecules.The kinetic radical yield and recombination curves substantially depend on the pressure and angle and of the rate of shear deformation produced by impact loading.
- Dadali, A. A.,Lastenko, I. P.,Aksenenkov, V. V.,Ivanov, A. N.
-
p. 150 - 153
(2007/10/02)
-
- INFLUENCE OF ONIUM SUBSTITUENT IN PHTHALOYL RING ON THERMODYNAMIC PARAMETERS OF EQUILIBRIUM BETWEEN DIMER AND FREE RADICALS OF 2-(4-DIMETHYLAMINOPHENYL)-1,3-INDANDIONES
-
2,2'-Bis diperchlorate and 2,2'-bis diperchlorate have very definite thermochromic and mechanochromic properties, owing to reversible dissociation into free radicals.The rupture energy of the central bond C2-C2' in 5-substituted 2,2'-bis in acetonitrile is 63-75 kJ/mole; in the dimer with the bulky 5-(2,4,6-triphenylpyridinium) substituent, the rupture energy is 51 kJ/mole.The equilibrium constants follow the Hammett equation (? = 1.53, acetonitrile, 293 K).Radicals with onium substituents are thermodynamically the most stable of the arylindandionyl radicals that are thus far known, owing to the significant contribution of electrostatic interactions.
- Pisarenko, L. M.,Nikulin, V. I.,Blagorazumov, M. P.,Neiland, O. Ya.,Paulin'sh, L. L.
-
p. 1379 - 1385
(2007/10/02)
-