Polymerization of N‐carbazolylacetylene by various transition metal catalysts and polymer properties

Abstract

N-Carbazolylacetylene (CzA) was polymerized in the presence of various transition metal catalysts including WCl 6 , MoCl 5 , [Rh(NBD)Cl] 2 , and Fe(acac) 3 to give polymers in good yields. The polymers produced with W catalysts were dark purple solids and soluble in organic solvents such as toluene, chloroform, etc. The highest weight-average molecular weight of poly(CzA) reached about 4 ϫ 10 4 . In the UV-visible spectrum in CHCl 3 , poly(CzA) exhibited an absorption maximum around 550 nm ( max ϭ 4.0 ϫ 10 3 M Ϫ1 cm Ϫ1 ) and the cutoff wavelength was 740 nm, showing a large red shift compared with that of poly(phenylacetylene) [poly(PA)]. Poly(CzA) began to lose weight in TGA under air at 310°C, being thermally more stable than poly(PA) and poly[3-(Ncarbazolyl)-1-propyne]. Poly(CzA) showed a third-order susceptibility of 18 ϫ 10 Ϫ12 esu, which was 2 orders larger than that of poly(PA).

Synthesis and Properties of Polyacetylenes Connecting Carbazole at the 2‐ and 3‐Positions: Effect of Polymerization Catalysts and Substitution Positions on the Optoelectronic Properties

“…et al [5] We have previously synthesized poly(N-carbazolylacetylene), which shows a third-order susceptibility. [6] We have also synthesized poly[3-(N-carbazolyl)-1-propyne] [7] and poly[1-( p-N-carbazolylphenyl)-2-phenylacetylene], [8] which show photoconductivity and redox activity. More recently, we have synthesized poly [9-(4-ethynylphenyl)carbazole] to find that the polymer obtained by the polymerization with WCl 6 -Bu 4 Sn catalyst exhibits UV-Vis absorption apparently at a longer wavelength than the MoCl 5 -Bu 4 Sn-based counterpart does.…”

Synthesis and properties of polyacetylenes carrying N-phenylcarbazole and triphenylamine moieties

“…1 H NMR spectra of 1, poly(1), 2, and poly(2). Polymer samples from run 1 in Table 1 and run 1 in Table 2. good compared to that of poly(N-ethynylcarbazole) [8] and poly [N-(4-ethynylphenyl)carbazole] reported previously [14]; the latter two polymers obtained with [(nbd)RhCl] 2 eEt 3 N catalyst are insoluble in common organic solvents including toluene, CHCl 3 and THF. Thus, it is clear that the substitution position greatly affects the solubility of the polymers.…”

“…We can say that the conjugation length of poly(1) is longer than that of poly(3,6-di-tert-butyl-N-(4-ethynylphenyl)carbazole) as expected. Unfortunately, we cannot compare the UVevis spectrum of poly(1) with those of Rh-based poly(N-ethynylcarbazole) [8] and poly(N-(4-ethynylphenyl)carbazole) [14], because the latter two polymers are solvent insoluble. Poly(2) exhibited the UVevis absorption peaks derived from the TPA moieties at 250e350 nm, and polyacetylene backbone above 350 nm.…”

“…Advincula and coworkers have also synthesized a series of Cz-substituted poly(phenylacetylenes) and examined the cross-linking reaction by electrochemical oxidation, where the redox potential decreases with increasing the alkyl chain length [7]. We have previously polymerized N-ethynylcarbazole with W, Mo, Rh, and Fe catalysts to obtain the polymer, which shows a third-order susceptibility of 18 Â 10 À12 esu, two orders larger than that of poly(phenylacetylene) [8]. We have also synthesized other polyacetylenes substituted with Cz, and examined the properties; e.g., poly (3,6-di-tert-butyl-N-(4-ethynylphenyl)carbazole) to find that the photoluminescence quantum yield of a W-based polymer was 15 times higher than that of an Rh-based one, and conducts electric current 40e50 times more easily under photo-irradiation than in the dark.…”

Synthesis and polymerization of phenylacetylene having two carbazole units and properties of the formed polymer

“…Several efforts have been made based on this concept, which include polyacetylenes carrying carbazoles synthesized by Tang and coworkers, 5 Advincula and coworkers, 6 and Tabata et al 7 We have previously synthesized poly(N-carbazolyl-acetylene), which shows a third-order susceptibility. 8 We have synthesized poly [3-(N-carbazolyl) 21-propyne] 9 and poly [1-(p-N-carbazolylphenyl) 22-phenylacetylene], 10 which show photoconductivity and redox activity. We have also synthesized poly [9-(4-ethynylphenyl)-carbazole] using WCl Sn catalyst, and reported that the polymer exhibits a distinct UV-vis absorption peak at a longer wavelength than the MoCl 5 -Bu 4 Sn-based counterpart does.…”