Switching high two-photon efficiency: from 3,8,13-substituted triindole derivatives to their 2,7,12-isomers.
Bridging the triindole core and triarylboryl acceptor by an ethenylene linker at the 3,8,13- or 2,7,12-position, the resultant 3-BET and 2-BET show two-photon absorption (TPA) cross sections of δ = 2100 and 2500 GM (at 810 nm by femtosecond pulses in THF), respectively. The TPA enhancement of the 2,7,12-isomers is also found when comparing 3-BYT and 2-BYT (δ = 870 and 1900 GM) and 3-NET and 2-NET (36 and 400 GM).
School of Chemistry and Chemical Engineering, Shandong University, 250100, Jinan, PR China.
Lei
L
Ji
Qi
Q
Fang
Mao-Sen
MS
Yuan
Zhi-Qiang
ZQ
Liu
Yu-Xiang
YX
Shen
Hong-Feng
HF
Chen