Switching High Two-Photon Efficiency: From 3,8,13-Substituted Triindole Derivatives to Their 2,7,12-Isomers

Abstract

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).

Experimental and Theoretical Studies of Quadrupolar Oligothiophene‐Cored Chromophores Containing Dimesitylboryl Moieties as π‐Accepting End‐Groups: Syntheses, Structures, Fluorescence, and One‐ and Two‐Photon Absorption

“…It has been reported by Wang and co‐workers23 that some arylBMes 2 compounds can act as mesityl transfer agents in Suzuki–Miyaura coupling reactions under certain conditions. The arylBMes 2 compounds are stable in Sonogashira and Heck reactions when using amine bases,12 so it is likely that only small basic groups such as fluoride and hydroxide ion can attack the bulky boron center causing problems in palladium‐catalyzed reactions. It is also possible that some protodeborylation of 2 Bpin occurred under our reaction conditions.…”

Recent developments in and perspectives on three-coordinate boron materials: a bright future

“…203 With three nitrogen π-donors and larger π-systems, 52 (1900 GM at 810 nm) and 53 (2500 GM at 820 nm) bear the largest two-photon cross sections among the octupolar triarylboranes reported to date. 205 Due to the fact that the wavelength window of the measurement was very narrow and the TPA maximum is very close to the one-photon absorption maximum, another much stronger higher energy TPA absorption band is also possible in the shorter wavelength region.…”

Replacing Two Chlorido Ligands by a Bipyridine Ligand in Ruthenium Nitrosyl Complexes with NO‐Release Capabilities: A Comparative Study

“…(4) The need for enhanced TPA efficiency for the · NO‐donating species may lead to the exploration of more promising symmetries in which the simple “push–pull” structure present in [ 1 ] + and [ 2 ] + is replaced by centrosymmetric or multipolar systems. These alternative symmetries require the synthesis of polymetallic complexes.…”