Comprehensive investigation of the solution photophysics and theoretical aspects of oligothiophenes of 1-7 rings

Publisher Website
Google Scholar
Abstract
Photophysical ($,, z,, $,, t,), absorption (So * S, and TI * T,) and emis- sion (fluorescence and phosphorescence) have been evaluated for thiophene (n= 1) and oligothiophenes (n=2-5,7). In addition k,, k,, and k,,, have been evaluated for n=2-5, 7. In general 4, increases from n=2 to 5 and becomes constant (n=5-7) whereas 9, decreases overall from n=2,3 (nearly same) to constancy at n=5,7. The k,,, progressively decreases and k, remains approximately constant as n increases from n=3 to 7. The zF progressively gets longer while zT gets shorter as n increases and both become constant at n=5,7. Based on k, (or z",) and other data, it is clear that the 'B-type state is always below the 'A-type state fron n=2 to and including n=7, in contrast to other existing predictions (for n=6 and greater). Although fluo- rescence exists for all compounds, except thiophene, no phosphorescence has been observed (I$~ s 5 x except thiophene. Mechanisms rationalizing the photophysical behavior are given.

This publication has 0 references indexed in Scilit: