Acid-Responsive Conductive Nanofiber of Tetrabenzoporphyrin Made by Solution Processing

Abstract

While cofacial one-dimensional (1-D) π stacking of a planar aromatic molecule is ideal for the construction of conduction systems, such molecules, including tetrabenzoporphyrin (BP), prefer to form edge-to-face stacking through CH-π interactions. We report here that the BP molecules spontaneously form a 1-D cofacial stack in chloroform containing 1% trifluoroacetic acid (TFA) and that a bundle of the formed nanofiber shows acid-responsive 1-D conductivity as high as 1904 S m. A small fraction (2.7%) of BP in the fiber exists in a cation radical state, and 1.5 equiv of TFA is located in an intercolumnar void. Dedoping and redoping of TFA with trimethylamine vapor results in 1300-2700-fold decreases and increases, respectively, in the conductivity and also the amount of the radical cation. The conductivity of the fiber also shows a correlation with the pK of acid dopants.

Crystal Engineering of Organic Optoelectronic Materials

“…17 Linear-shaped molecules with a low H/C ratio or large aromatic systems with a high surface-to-circumference ratio generally adopt offset face-to-face arrangement since C-H$$$p interactions are insufficient to stabilize edge-to-face stacking. 8 In particular cases such as electron donor-acceptor (D-A) pairs or radical p-stacking systems, [24][25][26][27] parallel face-to-face stacking can be achieved, which is beneficial for a one-dimensional packing motif. The p-p contacts associated with face-to-face stacking are almost in the range of 3.2~3.8 Å , which is an important index revealing the strength of p-p interactions.…”

Triazine and Porphyrin-Based Cross-Linked Conjugated Polymers: Protonation-Assisted Dissolution and Thermoelectric Properties

“…To confirm the integrity of the TPCP structure under different protonation degrees, FT-IR measurements were conducted and there were no new characteristic peaks observed (Supporting Information Figure S6), indicating that the TPCP structure had not undergone degradation and that it had retained its initial structure. Therefore, protonation-assisted dissolution can be attributed to the protonation of porphyrin segments in the TPCP [23,24] and the electrostatic repulsion effect.…”

New fused conjugated molecules with fused thiophene and pyran units for organic electronic materials

“…Considering that TTCTTC and TTTCTTTC possess high HOMO energy levels, we investigated their absorption spectra aer oxidation. It was reported that electron donors with high HOMO energy levels such as N-N linked bicarbazole or biacridine derivatives, 17 and tetrabenzoporphyrin, 18 can be oxidized by acids such CF 3 COOH. As shown in Fig.…”