Tröger's Base‐Containing Aromatic Polymers with Unexpected Properties Endowed by the Insertion of Alkyne Spacers

Abstract

Novel Tröger's base‐containing linear polymers are synthesized by the Pd‐catalyzed polycondensation of 2,8‐disubstituted Tröger's base monomers. Despite the nonplanarity of Tröger's base structure, there is a solubility problem for the resulting polymers. Careful selection of the comonomers and π‐spacers eventually produce high molecular weight polymers. All the polymers show high thermal stabilities with decomposition temperatures (Td5%) exceeding 300 °C. The optical and electrochemical properties of Tröger's base‐containing polymers are, to the best of our knowledge, investigated for the first time. They absorb UV light and emit a blue fluorescence in CH2Cl2 solutions with the quantum yield reaching 0.72. The polymers with ethynylene spacers display a remarkable light‐green fluorescence in thin films as a result of excellent intermolecular interactions. Also, the redox activities depend on the chemical structures of the comonomers and π‐spacers. Remarkably, Tröger's base‐fluorene copolymer does not show any oxidation peaks, whereas the ethynylene‐linked copolymer exhibits a well‐defined oxidation at ≈1.1 V (vs Ag/Ag+). The use of triphenylamine comonomers further enhances the redox activities. A facilitated oxidation occurs at the benzidine subunits, and a faster redox response is revealed by spectroelectrochemical measurements.

3,6-Carbazole vs 2,7-carbazole: A comparative study of hole-transporting polymeric materials for inorganic–organic hybrid perovskite solar cells

“…Analogously to the description in [50], a solution of 2 (0.392 g, 0.450 mmol) and 2,5-dibromo-3,4-ethylenedioxythiophene (0.136 g, 0.450 mmol) in toluene (5 mL) was degassed with nitrogen for 15 min. Pd 2 (dba) 3 (0.010 g, 0.011 mmol) and P( o -tolyl) 3 (0.015 g, 0.049 mmol) were added.…”

Synthesis of new cyano‐substituted analogues of Tröger's bases from bromo‐derivatives. A stereochemical dependence of long‐range (nJHH, n = 4, 5, and 6) proton–proton and proton–carbon (nJCH, n = 1, 2, 3, 4, and 5) coupling constants of these compounds

“…Troger's base (TB) is a chiral V‐shaped compound whose chirality is the result of two stereogenic nitrogen centres being unable to invert due to the presence of a methylene strap . TB analogues have exhibited outstanding applications in supramolecular chemistry, DNA recognition, optical and optoelectronic materials, among others. Chiral TBs have also been proven as promising catalyst in asymmetric reactions and chiral auxiliary in stereoselective syntheses .…”

Development of N-Type Semiconducting Polymers for Transistor Applications

“…Poly(aryleneethynylene)s, poly(arylenebutadiynylene)s, and platinum(II) polyyne polymers are an important class of conjugated polymers, whose optical and electrical properties have been studied for decades [23][24][25][26][27][28][29][30][31][32][33]. Most of these polymers are composed of electron-rich substances in the main chain, and accordingly, the [2+2] CA-RE with TCNE was attempted.…”