SOLVATION DYNAMICS OF CHROMOPHORES IN POLYETHERS

Steady-state and time-resolved optical techniques are employed to meas ure the solvation static and dynamics of large probe molecules in smal l polyethers. In ethylene glycol dimethyl ethers (n = 2, 3, and 4) we find that the solvation dynamics span from similar to 50 fs to more th an 100 ps. Three major time components can be resolved. The short time is bimodal with an ultrafast Gaussian component <70 fs followed by a similar to 2 ps component. The second component of 10-20 ps depends on the polymer size and is attributed to segmental motion. The long comp onent of,100 ps is ascribed to cooperative motion of the polymer matri x.