Photochemistry of compounds in the constrained medium cellulose—part 8. Long-range electron transfer from excited pyrene to Cu(II) cation

Abstract

Steady state spectroscopic techniques and laser flash photolysis have been used to investigate the photo-induced electron transfer from pyrene to cupric ions in cellophane films. The data indicate that the rate constant k( r) as a function of reactant separation r is given by k( r)=5×10 11exp(-0.61r)s -1 at 20° C. The rate constant decreases by a factor of 5 over the temperature range 20°C to -60°C which is attributed to a change of the adsorbed water in the cellophane; it then remains almost constant to 77 K.