Poly(3,4-alkylenedioxypyrrole)s as Highly Stable Aqueous-Compatible Conducting Polymers with Biomedical Implications

Abstract

sulting mixture was stirred at room temperature for 12 h. From this mixture, polymer 7 was obtained as a bright yellow solid (1.20 g, 99 %) by suction filtration, followed by washing with a large volume of methanol and drying under vacuum at 50 C for 8 h. Anal. (calcd. Br± (C 17 Polymer 8: To a solution of polymer 7 (500 mg) in freshly distilled THF (50 mL) benzeneboronic acid (120 mg) was added and argon was bubbled through the mixture for 10 min. Pd(PPh 3 ) 4 (40 mg) and 1 M Na 2 CO 3 solution (2 mL) were added sequentially. The mixture was stirred and refluxed under argon for 90 h. THF was removed under vacuum and water (100 mL) was added to the flask. Suction filtration and washing with a large volume of water gave a light gray solid. The solid was dissolved in chloroform then filtered through Celite. The filtrate was precipitated in methanol followed by stirring for 24 h. Polymer 11: By analogy with the preparation and purification of polymer 7, 2,5-dibromo-4-hexylpyridine 6 (1.219 g, 3.797 mmol) and 2,5-dimethoxy-1,4-benzenediboronic acid 9 (0.857 g, 3.797 mmol) were polymerized to yield polymer 11 as a bright yellow solid (1.20 g, 90 % (m, 6 H, ±OMe); the aromatic proton signals have similar shapes to those of polymer 7, with five peaks at d 6.9, 7.3, 7.6, 8.0, and 8.6, with a total integral of 4.5 H.Polymer 12: By analogy with the preparation and purification of polymer 8, polymer 11 was treated with benzeneboronic acid (11.3 mg), Pd(PPh 3 ) 4 (2 mg), and 1 M Na 2 CO 3 solution (1 mL) in THF (10 mL) to yield polymer 12 as a light gray solid (85 mg Polymer 13: By analogy with the preparation of polymer 7, 2,5-dimethoxy-1,4-benzenediboronic acid 9 (0.565 g, 2.50 mmol) and 2,5-dibromopyridine (0.592 g, 2.50 mmol) were polymerized to yield polymer 13 (0.50 g, 94 %). Due to the low solubility of the polymer in ordinary organic solvents, further purification was not possible, apart from washing the solid with large volumes of water and methanol. Anal. (calcd. Br±(C 13 H 11 NO 2 ) 5 ± Br) C 63.03 (63.77), H 4.41 (4.53), N 4.67 (5.72), Br 11.17 (12.90). The polymer was essentially insoluble in standard NMR solvents, so no NMR data were recorded.Polymer 16: By analogy with the preparation of polymer 7, 1,4-benzenediboronic acid (0.416 g, 2.509 mmol) and the ditriflate 15 (1.150 g, 2.509 mmol) were polymerized to yield polymer 16 as a pale brown solid (0.41 g, 69 %). Attempted purification of the polymer involved dissolving the crude solid in hot o-dichlorobenzene and filtering through Celite under vacuum, then precipitating the polymer with ethanol, followed by suction filtration and washing the precipitate with a large volume of ethanol, and drying for 8 h at 50 C under vacuum.

Electrochemical polymerization and properties of PEDOT/S-EDOT on neural microelectrode arrays

“…In recent years, poly(3,4-ethylenedioxythiophene) (PEDOT) has been of considerable interest because of the possibility of producing a material with linear chains due to the blocking of the 3,4-positions of the thiophene ring [5][6][7][8][9]. This material lacks the presence of undesired aÀb(b 0 ) and bÀb(b 0 ) couplings within the polymer backbone, and hence has high electrical conductivity and high electrochemical and thermal stability [10,11].…”

Incorporation of Conductive Materials into Hydrogels for Tissue Engineering Applications

“…Furthermore, it is essential to consider controlling the mechanical properties. Since unchanged PPy, like most other CPs, is crystalline, fragile, and susceptible to irreversible oxidation [74], there is no ideal candidate for tissue support materials. Therefore, to overcome such disadvantages, the development of dopants and PPy analogs are continuously being researched [75].…”

Chemical and Electrochemical Synthesis of Highly Conductive and Processable PolyProDOP-alkyl Derivatives

“…1). [5][6][7][8] For chemical synthesis of polymer, into a 100 mL three necked flasked equiped with a magnetic stirring bar, reflux condenser, and dropping funnel was placed 6 mmol of a monomer in 30 mL of methanol. The solution of an oxidant in methanol was charged into the dropping funnel and added to the solution containing a monomer with vigorous stirring at 0 o C. A Black precipitate was filtered through a glass frit funnel and washed with methanol several times.…”

“…Three monomers were synthesized according to the method that has been developed previously [6][7][8]) (see Fig. 1) and they were chemically polymerized by the method developed by Machida and coworkers.…”

“…[5][6][7][8] By analogy with 3,4-ethylendioxythiophene (EDOT), 9) an appending dioxyalkylene group across the 3-and 4-positions of the pyrrole leads to the polymer with vastly improved properties compared to the parent. With excellent physical properties of PXDOPs, they envisioned that the polymers could be tailored to be processable by appending a alkyl chain to the alkylene bridge of 3,4-propylenedioxypyrrole (ProDOP).…”