Elucidating the thermal degradation of carbazole‐containing platinum–polyyne polymers

Abstract

In this article, we present the significant influence of the substitution pattern of carbazole on the thermal stability of carbazole-containing platinum(II)-polyyne polymers. A series of the studies on the dynamic and isotherm conditions revealed a better thermal stability for the 3,6-carbazole based platinum(II)-polyyne polymer (36CbzPtP), where alkynes were located at the p-phenylene positions relative to the carbazole nitrogen atom, compared to that for the 2,7-carbazole based counter polymer (27CbzPtP), where the alkynes were located at the m-phenylene positions relative to the carbazole nitrogen atom. On the other hand, the thermogravimetrymass spectrometry-Fourier transform infrared technique applied to the two polymers revealed the same degradation mechanism, which probably involved the thermal decomposition of triethyl phosphine moieties and which was followed by the C C scission of hexadecyl chains. The carbazole moieties eventually underwent degradation when the temperature exceeded 415 C. Molecular modeling showed that polymer 27CbzPtP formed a linear structure, whereas polymer 36CbzPtP adopted a curved structures; this led to different packing modes of the polymer chains. This structural difference affected the efficiency of the initial degradation event of the triethyl phosphine groups. The curved structures of 36CbzPtP sterically protected the triethyl phosphine groups; this led to an increased thermal stability over that of 27CbzPtP.

Thermal stability and degradation mechanism of C60 fullerene‐based polymers

“…The bands characteristic of the alkyl groups were detected in the following regions for both polymers: 810–1100, 1100–1320, 1320–1570, and 1570–1800 cm −1 27 . The presence of the bands in the 2800–3050 cm −1 region, characteristic of the CH stretching vibrations of methylene, methyl, and methine groups, confirmed the aliphatic specificity of these decomposed compounds 28,29 . In addition, the peak at 1268 cm −1 corresponding to the CN stretching vibrations confirmed the decomposition of the 1,2,3‐triazole moieties 30 .…”

“…27 The presence of the bands in the 2800-3050 cm À1 region, characteristic of the C H stretching vibrations of methylene, methyl, and methine groups, confirmed the aliphatic specificity of these decomposed compounds. 28,29 In addition, the peak at 1268 cm À1 corresponding to the C N stretching vibrations confirmed the decomposition of the 1,2,3-triazole moieties. 30 As shown in Figure S11, which compares the FTIR spectra of both polymers at approximately the same temperature, the peaks corresponding to the alkyl groups (2800-3050; 810-1100 cm À1 ), and C N (1268 cm À1 ) were more intense in polymer C 60 P2 than in polymer C 60 P1.…”

Cu(I)‐catalyzed azide–alkyne cycloaddition synthesis and fluorescent ion sensor behavior of carbazole‐triazole‐fluorene conjugated polymers

“…In particular, heteroatom‐containing aromatic rings can selectively coordinate specific metal cations and anions in terms of ion–dipole interactions. One of the promising building blocks is carbazole, which is a nitrogen‐containing fused aromatic system that shows a well‐defined fluorescence 9–15 . In addition, the p K a value of the unsubstituted carbazole is 19.9, which is lower than those of pyrrole (23.0) and indole (21.0) 16 .…”