Conjugated Backbone System Research Articles

Synthesis and characterization of poly[2-ethynyl-N-(furoyl)pyridinium tetraphenylborate)

A polyacetylene polyelectrolyte with bulky counter anions was synthesized via the ion-exchange reaction of poly(2-ethynyl-N-(furoyl)pyridinium chloride) using sodium tetraphenylborate in a polar methanol solvent (Scheme 1). The analytical data on polymer structure revealed that the resulting polymer have the conjugated backbone system with the designed N-(furoyl)pyridinium tetraphenylborate substituents. The optical absorption spectrum of polymer showed a characteristic absorption peak in the visible region (up to 800 nm), which is strong evidence for the presence of the conjugated polyene backbone system. The resulting polymer exhibits absorption maximum peaks at 332 nm, 413 nm, and 500 nm. The photoluminescence peak was observed at 575 nm, which is corresponding to the photon energy of 2.16 eV. The resulting polymer exhibited the irreversible electrochemical behaviors between the doping and undoping peaks. Scheme 1. The synthesis of PEFP-TPB via ion-exchange reaction.

Electro-optical and electrochemical properties of poly[2-ethynyl-N-(α-isobutyryl)pyridinium bromide

In the present study, we synthesized a new conjugated polyelectrolyte with the N-(α-isobutyryl)pyridinium bromide as substituents via the spontaneous, catalyst-free polymerization of 2-ethynylpyridine using α-bromoisobutyryl bromide. The polymerization proceeded well to give the resulting poly[2-ethynyl-N-(α-isobutyryl)pyridium bromide] in high yield. The polymer structure was characterized by means of such instrumental methods as IR, NMR, and UV-visible spectroscopies to have the conjugated backbone system with the N-(α-isobutyryl)pyridinium bromides. Absorption spectrum of polymer showed the maximum peaks of 334 and 411 nm. The electrochemical property of polymer was measured and discussed. Based on cyclic voltammetry data, this polymer had the HOMO value of 5.25 eV.

Synthesis and Characterization of Poly[N-(3-butynyl)-2-ethynylpyridinium bromide

A new conjugated polyelectrolyte with the N-(3-butynyl)pyridinium bromide was synthesized via the non-catalyst polymerization of 2-ethynylpyridine by using 4-bromo-1-butyne. The polymerization proceeded well to give the resulting poly[N-(3-butynyl)-2-ethynylpyridium bromide] in 75% yield. The chemical structure of poly[N-(3-butynyl)-2-ethynylpyridium bromide] was characterized by such instrumental methods as IR, NMR, and UV-visible spectroscopies to have the conjugated backbone system with the designed substituents. The electro-optical and electrochemical properties of polymer were measured and discussed. Comparing absorption spectrum and cyclic voltammetry data, this polymer had the HOMO and LUMO values of 5.33 and 3.35 eV, which means the band gap of 1.98 eV.

Synthesis and characterization of poly(2-ethynyl-N-iodopyridinium tetraphenylborate)

Poly(2-ethynyl-N-iodopyridinium tetraphenylborate) (PEIP-TPB) was prepared via the ion-exchange reaction of poly(2-ethynyl-N-iodopyridinium iodide) by using sodium tetraphenylborate. The chemical structure of PEIP-TPB was characterized by such instrumental methods as IR, NMR, and UV-visible spectroscopies to have the conjugated backbone system with the designed N-iodopyridinium tetraphenylborate as substituents. The broad and weak absorption peak of π→ π* interband transition of polymer main chain starts around 800 nm in the optical absorption spectrum of polymer. The PEIP-TPB polymer shows different solubility behaviors with that of precursor polymer. This polymer were mostly soluble in such organic solvents as N,N-dimethylformamide, dimethylsulfoxide, N-methylpyrrolidine, etc. The polymer exhibited the gradual weight losses over the temperature of 132 °C.

An ionic polyacetylene derivative with the N-[(triethylene glycol)methyl ether]pyridinium tosylate

ABSTRACTThe non-catalyst polymerization of 2-ethynylpyridine using tri(ethylene glycol)methyl ether tosylate yielded an ionic polyacetylene with the N-[(triethylene glycol)methyl ether]pyridinium tosylate substituents. The polymerization proceeded well in homogeneous manner to give the resulting poly{2-ethynyl-N[(triethylene glycol)methyl ether]pyridinium tosylate} in moderate yield. The polymer was completely soluble in such organic solvents as methanol, DMF, DMSO, NMP including water. The chemical structure of the resulting polymer was characterized by such instrumental methods as IR, NMR, and UV-visible spectroscopies to have the conjugated backbone system with the N-[(triethylene glycol)methyl ether]pyridinium tosylate. The absorption spectrum starts around 600 nm, which is due to the π→ π* interband transition of conjugated polymer system. HOMO and LUMO level were 5.46 and 3.39 eV. The electrochemical properties of polymer was also measured. This polymer exhibited initial onset voltage of 0.73 V for oxidation and stable redox property up to 50 cycles.

Electro-optical and electrochemical properties of poly(1,6-heptadiyne) derivative with a bulky (t-butyldiphenylsiloxy)methyl substituents

ABSTRACTA conjugated cyclocopolymer with a bulky substituents was synthesized via the MoCl5-catalyzed cyclopolymerization of diethyl dipropargylmalonate and 4,4′-bis[(tert-butyldiphenylsiloxy)methyl]-1,6-heptadiyne. The chemical structure of polymer was characterized by NMR (1H-, 13C-), IR, and UV-visible spectroscopies to have a conjugated backbone system with the designed substituents. The polymer showed characteristic UV-visible absorption band and absorption maximum value of 507 nm. Photoluminescence spectrum exhibited maximum peak at 594 nm, which corresponds to the photon energy of 2.09 eV. Band gap of cyclic copolymer was 2.01 eV.

Synthesis and Characterization of Poly[N-(4-nitrobenzenesulfonyl)-2-ethynylpyridinium chloride

An ionic polyacetylene with 4-nitrobenzenesulfonyl substituents was easily prepared via the non-catalyst polymerization of 2-ethynylpyridine using 4-nitrobenzenesulfonyl chloride. The polymerization proceeded in homogeneous manner to give a moderate yield of polymer (65 %). The polymer structure was characterized by such instrumental methods as IR, NMR, and UV-visible spectroscopies to have the conjugated backbone system with the designed N-(4-nitrobenzenesulfonyl)pyridinium chloride. The photoluminescence peak was observed at 584 nm corresponding to a photon energy of 2.12 eV although it is weak due to nitro group. Based on absorption spectrum, band gap was 2.16 eV. The cyclic voltammograms of polymer exhibited the electrochemically stable window at the −1.8 ∼ 1.50 V region. Oxidation and reduction were started at 0.43 and −0.9 V and had stable electrochemical property up to 30 cycles.

A Polyacetylene via the Cyclopolymerization of 4,10-Bis(diethylmalonate)-1,6,11-dodecatriyne: Synthesis and Characterization

A new class of polyacetylene was synthesized via the cyclopolymerization of 4,10-bis(diethyl malonate)-1,6,11-dodecatriyne by using MoCl5-EtAlCl2 catalyst system. The polymerization proceeded in mild homogeneous manner to give 32% yield of polymer. The chemical structure of resulting polymer was characterized by NMR (1H-, 13C-), IR, and UV-visible spectroscopies to have a conjugated backbone system. The polymer showed characteristic wide UV-visible absorption band and PL maximum peak at 530 nm corresponding to the photon energy of 2.34 eV. The cyclic voltammogram of polymer showed the stable electrochemical window in the range of of −1.50V to +1.50V. From the CV measurements, the HOMO energy level of the polymer was calculated to be 5.55 eV.

Synthesis and Characterization of a Polyacetylene Derivative: Poly(2-ethynyl-N-methylpyridinium Tetraphenylborate)

A monosubstituted ionic polyacetylene with bulky counter anions was prepared via the ion-exchange reaction of precursor polymer by using sodium tetraphenylborate. The chemical structure of the resultiing polymer was characterized by such instrumental methods as IR, NMR, and UV-visible spectroscopies to have the conjugated backbone system with the designed functional groups. The absorption spectrum starts around 770 nm, which is due to the π→ π* interband transition of conjugated polymer system. The photoluminescence maximum peak of polymer was located at 576 nm, which corresponds to the photon energy of 2.16 eV. This polymer exhibited the irreversible electrochemical behaviors between the doping and undoping peaks.

Synthesis and Characterization of Poly[p-(N-ethylbenzenesulfonate sodium)-2-ethynylpyridinium Bromide

A substituted polyacetylene with benzenesulfonate functional groups was synthesized from the non-catalyst polymerization of 2-ethynylpyridine using sodium 4-(2-bromoethyl)benzenesulfonate. The activated acetylenic triple bond of monomeric N-substituted-2- ethynylpyridinium bromide, formed at first quaternarization process of 2-ethynylpyridine by sodium 4-(2-bromoethyl)benzenesulfonate was susceptible to linear polymerization. Instrumental analysis datas revealed that the polymer had the fully conjugated backbone system with the designed substituents. The photoluminescence spectrum of polymer showed that the photoluminescence peak is located at 545 nm, corresponding to a photon energy of 2.28 eV.

Synthesis and Characterization of Poly[N-(2-ethyl pyrroyl)-2-ethynylpyridinium Bromide

A monosubstituted polyacetylene having two aromatic heterocycles (pyridine and pyrrole) was easily prepared via the uncatalyzed polymerization of 2-ethynylpyridine using 1-(2-bromoethyl)pyrrole. The polymerization proceeded well in homogeneous manner to give a moderate yield of polymer (70%). The chemical structure of resulting polymer was characterized by such instrumental methods as IR, NMR, and UV-visible spectroscopies to have the conjugated backbone system with the designed N-(2-ethylpyrroyl)pyridinium bromide. The absorption spectrum starts around 800 nm, which is due to the π→ π* interband transition of conjugated polymer system. The photoluminescence spectra of polymer showed that the photoluminescence peak is located at 574 nm, corresponding to a photon energy of 2.16 eV.

Synthesis and Characterization of a Polyacetylene Derivative Containing Amine Functional Groups

A monosubstituted polyacetylene having amine functional groups was prepared via the polymerization of 3-ethynylaniline by using transition metal catalysts. The polymerization proceeded well in homogeneous manner to give a relatively high yield of polymer. The polymer structure was characterized by such instrumental methods as IR, NMR, and UV-visible spectroscopies to have the conjugated backbone system with the designed functional groups. The absorption spectrum starts around 700 nm, which is due to the π→ π* interband transition of conjugated polymer system. This polymer exhibited the irreversible electrochemical behaviors between the doping and undoping peaks.

Synthesis and characterization of an ionic conjugated polymer: Poly[2‐ethynyl‐N‐(2‐thiophenecarbonyl) pyridinium chloride

AbstractThe activated polymerization of 2‐ethynylpyridine by using 2‐thiophenecarbonyl chloride yielded the corresponding conjugated ionic polymer, poly[2‐ethynyl‐N‐(2‐thiophenecarbonyl)pyridinium chloride] (PETCPC). The polymerization proceeded well to give high yield of polymer without any additional initiator or catalyst. The instrumental analysis data on polymer structure indicated that the present ionic polymer have a conjugated polymer backbone system having N‐(2‐thiophenecarbonyl)pyridinium chloride as substituents. The photoluminescence maximum peak of PETCPC was located at 573 nm, which corresponds to the photon energy of 2.16 eV. The aromatic functional substituents in the conjugated backbone system shift PL maximum values because it makes different molecule arrangement. The cyclovoltamograms of PETCPC exhibited the electrochemically stable window at −1.24 to 1.80 V region. It was found that the kinetics of the redox process of polymer might be controlled by the reactant diffusion process from the experiment of the oxidation current density of polymer versus the scan rate. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6153–6162, 2009

POLYMERIZATION OF 1-BUTYL-2-TRIMETHYLSILYLACETYLENE BY TRANSITION METAL CATALYSTS

New silicon-containing disubstituted polyacetylene was prepared by the polymerization of BTMSA having two bulky substituents (n-butyl and trimethylsilyl) using transition metal catalysts. The polymerization proceeded in a mild manner and the final polymer yield was generally lower than those of silicon-containing monosubstituted acetylenes by the similar catalyst system. The characterization on the polymer structure revealed that the resulting poly(BTMSA) have a conjugated backbone system, but the polymers have peculiar copolymer composition of poly-(BTMSA) and poly(1-hexyne) due to the spontaneous desilylation during the polymerization. The fluoride-ion induced desilylation of poly(BTMSA) using n-Bu4N+F− in THF yielded a completely desilylated product, pure poly(1-hexyne).