Functionalization of poly(bis‐thiophene methine)s via facile C–C bulk polymerization and their application as chemosensors for acid detection

Abstract

Up to now, 3,4‐ethylenedioxythiophene (EDOT) or its modified analogs are indispensable units or subunits in all successful monomers for polythiophene synthesis through solid‐state polymerization (SSP). Here, a more open thiophene‐(CH(R))‐thiophene platform was developed successfully and corresponding poly(bis‐thiophene methine)s were obtained via C–C SSP or melt‐state polymerization (MSP), that is, bulk polymerization. Meanwhile, the observation of quite long effective Br–Br distance of 5.634 Å, which is more than 50% of halogen's double van der Waals radius (2rw), would help us to understand powerful capability of modulation of molecule movement and reaction under SSP. In addition, these polymers were further employed as acid sensors and they show highly sensitive response to HCl, MeSO3H, BF3‐OEt2, and HNO3. The detailed experiment reveals that P1 has the detection limit of 3.35 × 10−5 M for HCl. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 1676–1683

Synthesis of Conjugated Main-Chain Ferrocene-Containing Polymers through Melt-State Polymerization

“…PFcTP8 has versatile oxidation behavior in comparison to PFcT8 , such as oxidation peaks at 0.31, 0.6, and 1.2 V, which are assigned to the oxidation of the thiophene-methine structure. The property of multistep irreversible oxidation of PFcTP8 is similar that of our previously reported poly­(thiophene methine) derivatives. , …”

“…After reaction at 110 °C for 48 h, unreacted monomer was first removed by hexane and the final product was extracted by Soxhlet extraction with dichloromethane as solvent. The polymerization temperatures of both Fc-containing polymers are lower than those of our previously reported thiophene-methine based metallopolymers but higher than those other metal-free polymers with a thiophene-methine structure …”

“…The polymerization temperatures of both Fc-containing polymers are lower than those of our previously reported thiophenemethine based metallopolymers 40 but higher than those other metal-free polymers with a thiophene-methine structure. 51 The preparation details and physical properties of metallopolymers are given in Table 1. The molecular weights (M n ) of PFcT8 and PFcTP8 are 7.8 and 11.6 kDa, respectively, corresponding to polymerization degrees (DPs) of 13 and 10 (GPC traces are available in Figure S1).…”

“…The property of multistep irreversible oxidation of PFcTP8 is similar that of our previously reported poly(thiophene methine) derivatives. 42,51 The thermal stabilities of the prepared polymers were investigated by thermogravimetric analysis (TGA), which was recorded in the range of room temperature to 580 °C under a nitrogen atmosphere at a heating rate of 10 °C min −1 . As shown in Figure 6, PFcT8 is stable when the temperature is lower than 254 °C, and a small platform at 254−325 °C that results from further polymerization of polymer is observed.…”

Quinoidal conjugated polymers with open-shell character

“…In a recent report, a C-C bulk polycondensation reaction was used on the bisthiophene methine monomer, affording P16 after partial oxidation. 92 Other aromatic building blocks, e.g., diketopyrrolopyrrole, could also be connected with thienoquinodimethane units through Stille coupling polymerization, affording the donor-acceptor copolymer P17. 93…”