Vibrational energy accumulation in dendrimers by infrared radiation, inducing nonlinear dependence of isomerization rates on the low light intensity

Isomerization reactions were found to be induced in dendrimers by weak infrared radiation. The rate constant was nonlinear to the intensity of the radiation, despite its very low intensity. We propose a possible mechanism for it. The radiation increases the average number of vibrational quanta, pushing up the effective temperature of the vibrational mode. The nonlinearity is brought about by the increase in the effective temperature at the reaction site as a result of vibrational transfer in the dendrimer. However, it is necessary for the vibrational decay to be very slow for this mechanism. (C) 2001 Elsevier Science B.V. All rights reserved.