D‐π‐A Conjugated Molecules for Optoelectronic Applications

Abstract

Dipolar chromophores consisting of electron donor (D) and electron acceptor (A) groups connected through a conjugated π-bridge have been actively studied and integrated in optoelectronic and electronic devices. Generally, such π-conjugated molecules provide substantial delocalization of π-electrons over the molecules. Here, a brief overview of recent research on D-π-A dipolar chromophores including their syntheses and several promising applications is reported, especially in nonlinear optical devices and organic photovoltaics. Structure/property relationships are discussed in order to exploit the potentials by tuning the π-electron density, polarizability, and HOMO-LUMO band gap of the chromophores. Some of the examples may well set the stage for chip-scale integration of optoelectronics as well as the realization of an important array of new device technologies.

Synthesis and Properties of New Multiple TCNE Adducts from Dialkynyl‐N‐(het)arylpyrroles

“…These particular chromophores are push–pull conjugated molecules consisting of electron donor (D) and electron acceptor (A) groups connected through a conjugated π‐bridge. Simple variation of the D/A chemical combination offers an easy way to tune the frontier orbital energy levels of the molecule for suiting its targeted application . Furthermore, such D–π–A conjugates often display a broad absorption spectrum owing to intramolecular charge transfer (ICT) and π–π* absorption bands.…”

Pyrrolopyrrole Aza‐BODIPY Analogues as Near‐Infrared Chromophores and Fluorophores: Red‐Shift Effects of Substituents on Absorption and Emission Spectra

“…Dye molecules exhibiting intense absorption and emission in the near‐infrared (NIR) region have been attracting much attention in recent years, because of their potential applications in organic photovoltaics, organic light emitting diodes, and bioimaging . To shift the absorption and emission of conventional chromophores into the NIR region, extension of their π‐conjugated systems and introduction of donor‐acceptor substituents have been frequently attempted as basic strategies . Among a variety of chromophores, we focused on diketopyrrolopyrrole (DPP) as a basic chromophore structure, and extended its conjugated system through the carbonyl moieties to shift its UV/vis absorption and emission into the red .…”

“…[8][9][10][11][12] To shift the absorption and emission of conventional chromophores into the NIR region, extension of their π-conjugated systems and introduction of donor-acceptor substituents have been frequently attempted as basic strategies. [13,14] Among a variety of chromophores, we focused on diketopyrrolopyrrole (DPP) [15][16][17] as a basic chromophore structure, and extended its conjugated system through the carbonyl moieties to shift its UV/vis absorption and emission into the red. [18,19] Based on this molecular design, recently, our group reported a dimeric aza-boron dipyrromethene (aza-BODIPY) analogue, named pyrrolopyrrole aza-BODIPY (PPAB, Figure 1), as a new class of blue chromophores and red fluorophores.…”

Structural Dependence of Non-Linear Optical Properties of Molecules Containing Naphthalene Linked to Nitrophenyl Group–A DFT Study

“…The strong charge transfer between such groups operating across the entire system considerably adds to the optical nonlinearity of structure [10][11][12]. The large value of first hyperpolarizability (β), which is the measure of nonlinear optical activity, is attributed to intramolecular charge transfer which occurs due to the movement of electron cloud from electron donor to acceptor groups through a π conjugated framework [13][14][15][16]. The designing of new nonlinear optical materials relies heavily on the theoretical prediction of accurate electro-optical properties for aforementioned systems.…”