Synthesis and Optical Properties of Tetraaryl‐1,4‐dihydropyrrolo[3,2‐b]pyrroles

Abstract

Dedicated to Prof. Atsuhiro Osuka on the occasion of his 55 th birthday uptake of selected dyes was demonstrated.

Pyrrolo[3,2‐b]pyrroles—From Unprecedented Solvatofluorochromism to Two‐Photon Absorption

“…[10b] Two new key compounds 6 and 7 bearing 4-nitrophenyl- and 4-trifluoromethylphenyl substituents at position 2 and 5 were synthesized for this study from the corresponding aldehydes 1 and 2 , primary aromatic amines 3 and 4 and diacetyl ( 5 ) (Scheme 1). These compounds have been obtained in 36% and 35% yield, respectively.…”

“…In contrast to 7 , the optical properties of compound 6 are non-typical for known TAPP molecules [10–12] as 6 is remarkably affected by the solvent polarity. The absorption bands are bathochromically shifted as a consequence of the stronger polarization of the electronic structure of 6 compared with 7 .…”

“…Although the arrangement of electron-donating and electron-withdrawing groups is crucial for modulating the non-linear response, the actual electron density of the A, D moieties may also guide the increase of the two-photon absorption cross-section. Recently we discovered a new and efficient methodology for the synthesis of pyrrolo[3,2- b ]pyrroles, [10] the most electron-rich heterocycle among aromatic two-ring systems. [11] It became tempting to utilize this scaffold in the construction of even stronger quadrupolar A-D-A chromophores and to study their two-photon absorption properties.…”

“…In a preliminary study, we found that for a series of TetraAryl-1,4-dihydroPyrrolo[3,2- b ]Pyrroles (TAPPs), the two-photon absorption cross-sections reach values of σ 2PA ~700 GM at 700 nm, limited by the wavelength tuning range of the laser system. [10b,12] Tetra- and hexa-substituted pyrrole[3,2- b ]pyrroles are centrosymmetric, while the pentasubstituted compounds are nominally non-centrosymmetric, even though their backbone structure still behaves in a centrosymmetric manner. The remaining uncertainty concerning the location and values of 2PA maxima and the potential use of dyes possessing large non-linear responses at wavelengths shorter than 700 nm in areas such as two-photon excited polymerization [13] and optical limiting [14] prompted us to undertake a more detailed study of the origin of the one- and two-photon absorption characteristics of these molecules.…”

Properties of Polymorphism and Acid Response of Pyrrolopyrrole-based Derivative with Aggregation-induced Emission Behavior

“…由于并吡咯被认为是 10π 电子体系中电子给体能力 最强的的功能单元 [13] , 所以在酸性环境中, 酸碱相互作 用对并吡咯化合物的发光行为会造成影响. 我们在前期 工作中研究发现四苯基并吡咯(DPPTP)对三氯甲烷有荧 光淬灭的响应, 原因是三氯甲烷在光照条件下分解成氯 化氢气体与 DPPTP 相互作用使其荧光淬灭 [14] .…”