Intramolecular excimer formation in polymers: Pyrene Labelled Polyvinylacetate |
| |
Authors: | Carla Cuniberti A. Perico |
| |
Affiliation: | Centro Studi Chimico Fisici di Macromolecole Sintetiche e Naturali, Consiglio Nazionale delle Ricerche, Università di Genova, Corso Europa 30, 16132 Genova, Italia |
| |
Abstract: | The rate constant for intramolecular excimer formation between pyrenyl side-groups, in a polyvinylacetate chain at a mean separation of 200 bonds, has been measured as a function of molecular weight, solvent viscosity and solvent thermodynamic power. Above M = 1 × 105, the rate constant is 1.4 × 107 sec?1 in low viscosity bad solvents. This value is about twenty times that for the rate constant of the analogous reaction between the two terminal groups in a chain with a mean end-to-end separation of 200 bonds. Increases of the viscosity and of the thermodynamic power of the solvent depress the rate constant, in agreement with the behaviour expected for a diffusion controlled reaction. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|