The impact of interplay between electronic and steric effects on the synthesis and the linear and non-linear optical properties of diketopyrrolopyrrole bearing benzofuran moieties

Abstract

Benzofuran has been proven to be the versatile substituent for tuning the optics of diketopyrrolopyrroles.

An Efficient Method for the Programmed Synthesis of Multifunctional Diketopyrrolopyrroles

“…The combined effect of this substituent and 4‐Me 2 NC 6 H 4 (DPP 13 ) give a record high λ abs =598 nm and λ em =672 nm in DCM. These values are comparable to the symmetrical DPP possessing two 6‐diethylaminobenzofuryl substituents . The theory confirms such a conclusion as comparison of the HOMO and LUMO orbitals for 13 indicates that the electron density shift towards the DPP core upon photoexcitation is much more pronounced in the case of the 2‐(7‐(dimethylamino)naphtho[2,3‐ b ]furan‐2‐yl) substituent than for the 4‐Me 2 NC 6 H 4 moiety (Figure S1 in the Supporting Information).…”

“…7°) is known to lead to significant changes in the photophysical properties of the resultant N , N ‐dialkylDPPs, with an especially notable bathochromic shift in absorption . The lower dihedral angle allows the substituent to have a greater contribution to the π‐system of the DPP core in the ground state . Along these lines, the replacement of 4‐bromophenyl with a thienyl substituent ( 21 vs. 24 ) leads to a 30 nm red‐shift of absorption (Table ).…”

Visible light communication with efficient far-red/near-infrared polymer light-emitting diodes

“…DPP derivatives are versatile dyes exhibiting a favourable combination of optoelectronic properties [37][38][39] that have been extensively investigated and exploited in a very broad range of applications, including organic transistors 40 , solar cells 41 and OLEDs 42 . Interestingly, the optical properties of DPP can be drastically modified by leveraging its highly electron-poor nature and the socalled "push-pull" approach to obtain red-to-NIRemitting derivatives that combine both enhanced nonlinear optical properties and high photoluminescence (PL) quantum efficiencies 43 .…”

Addressing the autofluorescence issue in deep tissue imaging by two-photon microscopy: the significance of far-red emitting dyes

“… 12 – 14 As a result, 2P absorbing dyes with large two-photon absorption cross-section (TPACS) values, for example over 1000 GM, are currently available. 12 , 15 However, these dyes are large in size and highly hydrophobic, causing them to be sparingly soluble in aqueous media and thus this limits their use in the 2P imaging of biological systems. A handful of dyes with molecular weights of several hundred, such as acedan (2-acetyl-6-aminonaphthalene), naphthalimide, and rhodamine dyes, are currently used in tissue imaging 16 but these dyes cause significant autofluorescence (see below).…”