Synthesis, Crystal Structures, and Photophysical Properties of Triphenylamine-Based Multicyano Derivatives

Abstract

A new series of intramolecular charge transfer (ICT) molecules were synthesized by attaching various strong electron-withdrawing groups to a triphenylamine backbone. Relationships between chemical structures and optoelectronic properties of these compounds were investigated with X-ray diffraction, cyclic voltammetry, absorption spectroscopy, and density functional theory calculations. It is shown that the compounds exhibit intensive ICT interactions leading to substantial extension of their absorption spectral response, which may be potentially used for efficient solar cells.

Postfunctionalization of aromatic polyamine by [2+2] cycloaddition of 7,7,8,8-tetracyanoquinodimethane with side chain alkynes

“…The first reduction potential (E red,1 ) of P2 (x ? y = 1) was clearly detected at -0.77 V. This potential is comparable to those of the small donor-acceptor molecules [42][43][44], indicating that the side chain chromophores of P2 are almost independent of each other. This is probably caused not only by the sp 3 -hybridized nitrogen atoms in the polymer main chain, but also by the significant twist between the repeating units.…”

Tuning electron–hole distance of the excitons in organic molecules using functional groups

“…Investigations of excitons generated in organic materials have been explicitly and exclusively carried out for organic polymers or aggregates and at the interface [10][11][12][13][14][15][16][17]. The excitonic properties measured from these studies not only reflect the characteristics of individual excitons but also include excitonic interactions.…”

“…Triphenylamine derivatives have been greatly used as materials in solar cell applications due to their high extinction coefficient, excellent hole mobility, and strong electron donating ability [17,[22][23][24][25][26][27]. For instance, using a triphenylamine derivative, 4-vinyl-N,N-di(p-tolyl)aniline (MTPA) as donor, to generate excitons, and a triazine (TRC) and an anthraquinone derivative (AEAQ) as acceptors, we developed a donor-acceptor1-acceptor2 architecture to assist transportation and separation of electron-hole pairs such that the lifetime for charge recombination in the supramolecule (MTPA-TRC-AEAQ) is further elongated with respect to that of a donor-acceptor architecture (MTPA-TRC) [27].…”

Tuning the HOMO–LUMO gap of donor-substituted benzothiazoles

“…BTs 3, 5 and 6 exhibits irreversible oxidation wave corresponding to the oxidation of triphenylamine unit in the region between 0.52 V to 0.65 V. 20 On the other hand BTs 4, 7 and 8 exhibit reversible oxidation wave corresponding to the oxidation of ferrocene to ferrocenium ion in the region between 0.10 V to 0.45 V. 12b The TCBD and DCNQ linked BTs 5-8 exhibit higher oxidation potential compared to BTs 3 and 4 reflecting strong electronic communication.…”