Donor acceptor interactions in polymeric systems, 1. Synthesis and properties of polyamides having the carbazole group in the main chain

Abstract

Low temperature polymerizations of 3,6-diamino-9-ethylcarbazole (1 b) with the diacyl dichlorides 2 a -e were investigated. In all cases polyamides of high relative molecular mass ( [ q ] = 1 .lo2 cm3 g-'). could be obtained. These polyamides are polymeric electron donors in which the donor units are arranged with regular intervals. Donor acceptor interactions between polyamides and 1,3,54rinitrobenzene were studied. In comparison with the monomeric model compound 9-ethyl-3,6-bis(propionylamino)carbazole (lc) the polymer donor showed a higher stability constant. However, there is no regularity in the sequence of stability constants in respect to the number of methylene units separating two carbazole groups. There is a possibility that donor units in the polymer molecules might be located in such a way that each donor unit could cooperate to form a donor-acceptor complex. N o specific interactions between the carbazole groups could, however, be detected by fluorescence spectroscopy. The importance of solvent effects was expressed by the results of absorption and emission spectroscopy. Z U S A M M E N F A S S U N G :Tieftemperatur-Polymerisationen von 3,6-Diamino-9-athylcarbazoI (1 b) mit den Diacyldichloriden 2 a -e wurden untersucht. In allen Fallen wurden Polyamide mit hoher rel. mol.Masse ( [ v ] = 1 .lo2 cm3 g-') erhalten. Die Polyamide erwiesen sich als polymere Elektronendonatoren, in denen die Donator-Einheiten in regelmaoigen Abstanden angeordnet sind. Donator-Acceptor-Wechselwirkungen zwischen Polyamiden und 1,3,5-Trinitrobenzol wurden untersucht. Im Vergleich zur monomeren Modellsubstanz, dem 9-Athyl-3,6-bis@ropionyl amino)carbazol (1 c) zeigten die polymeren Donatoren eine hohere Stabilitatskonstante. Es besteht jedoch keine RegelmaRigkeit in der Folge der Stabilitatskonstanten im Hinblick auf die Zahl der Methylen-Einheiten, die die Carbazolgruppen trennen. Es ist moglich, daB die Donator-Einheiten in den Polymer-Molekiilen derart angeordnet sind, daR jede Donator-Einheit am Aufbau eines Donator-Acceptor-Komplexes beteiligt ist. Spezifische Wechselwirkungen zwischen den Carbazolgruppen konnten mit Hilfe der Fluoreszenz-Spektroskopie nicht festgestellt werden. Die Ergebnisse der Absorptions-und Emissionsspektroskopie bringen die Bedeutung von Losungsmitteleffekten zurn Ausdruck.

Synthesis and Characterization of Aromatic Polyimide Containing 3,6-Diamino-9-Alkylcarbazole and Aromatic Tetracarboxylic Dianhydrides

“…3,6-Diamino-9-ethylcarbazole (1a) was prepared by nitration of 9-ethylcarbazole and the reduction with hydrogen using palladium on carbon, as reported in [22], and purified by the recrystallization from toluene and sublimation under reduced pressure. 9-Hexylcarbazole was synthesized by N-alkylation of carbazole with n-hexyl bromide and sodium hydride [23].…”

“…However, the diamines, especially 1a, were very labile to oxygen, yielding coloured compounds. In the method reported, 1a was purified by recrystallization [22]; however, the coloured compound was not removed effectively. Thus, upon sublimation under reduced pressure, the yellow crystals of 1a were obtained.…”

Synthesis and properties of poly(3,6‐N‐alkylcarbazolyl methylene)

“…Polymers containing pendant carbazole groups have been widely investigated in view of their unique physicochemical properties such as photoconductivity and CT complex formation (1)(2)(3)(4)(5)(6). However, few studies on polymers having carbazole units in the main chain have so far been reported (7)(8)(9).…”

Polymere charge‐transfer‐komplexe auf der basis von polyvinylalkoholacetalen, 4

“…CH(CH,)z, 97), 181(12), 180 (208 -CO, 89), 179(19), 152, 87 (ll), 56 (11). NMR (CDC13): 6 = 0,87 (d; -CH<ZE, 6H), 1 , l -1,53 (m; -CH,-CH-CH,, 1 H), 3,67 -4,43 (m; -O-C~2-CH2-C~2-O-, 4H), 5,58 (s; -O-Cg-O-, 1 H), 7 -8,2 (m; aromat.…”