Nitroxide-Mediated Polymerization of Styrenic Triarylamines and Chain-End Functionalization with a Ruthenium Complex: Toward Tailored Photoredox-Active Architectures

Abstract

The preparation of redox-active polymers and the chainend functionalization with one ruthenium complex was investigated in detail. A series of substituted monomers, i.e., styrenic triarylamines bearing methyl, fluoro, or methoxy substituents, were prepared by a one-pot Hartwig−Buchwald coupling. The nitroxide-mediated polymerization (NMP) was studied by variation of the functional initiators, the monomer-to-initiator ratios, and the solvent. The kinetic analysis of the prototypical methyl-substituted triarylamine shows the controlled polymerization up to 75% conversion, but a considerable decrease of the polymerization rate was observed during the course of the reaction. Both chain-end functionalities of the purified oligomers were subsequently utilized, i.e., the nitroxide to serve as a macroinitiator for an additional NMP step and the chloromethyl group to introduce one ruthenium complex at the chain terminus. The products were analyzed in detail by size-exclusion chromatography, NMR spectroscopy, and mass spectrometry. The optical and electrochemical properties of the prepared poly(triarylamine)s show the application potential as charge transport materials in conjunction with the photoactive ruthenium complex.

Porous Carbons – Hyperbranched Polymers – Polymer Solvation

“…Recently, one research group has reported the production of porous carbons and porous carbon composites using a high temperature, high pressure system [115]. The only other study that has addressed the issue of porous carbon production via a high pressure system is in the Chinese language [116]. In the study, SBA-15 was used alongside a surfactant that acted both as a soft template and carbon source.…”

“…Hyperbranched poly(aryl ester)s via the polycondensation of A 2 and B 3 monomers were also prepared utilizing the A 2 + B 3 approach by Lin and Long [116]. A dilute bisphenol A (A 2 ) solution was added slowly to a dilute 1,3,5benzenetricarbonyl trichloride (B 3 ) solution at 25 C to prepare hb poly(aryl ester) s in the absence of gelation (see Table 1, entry 3 for monomer combination).…”

“…Here, main-chain polymers were introduced [110,111], including TCNQ polymers decorated with dendrons [112]. Polymers with porphyrin units in the main chain and fullerene side groups are described as electroactive [113], as well as polymers with azo-groups in the main chain [114] and triarylamines in the side chain [115][116][117][118]. By proper functionalization and architecture, even poly(thiophene) [119] and oligoaniline [120][121][122] and derivatives [123] become soluble in different solvents.…”

“…End-group modification is also known (e.g., see Fig. 12) [116,206,207]. For cobalt complexes, dendrimers with polypyridyl end groups were prepared, whose solubility can be manipulated directly by electrochemical means [208].…”

Electrogenerated networks from poly[4-(diphenylamino)benzyl methacrylate] and their electrochromic properties

“…Polymerization via reversible addition-fragmentation chain transfer (RAFT) can be only readily mediated using xanthates or dithiocarbamate as the chains transfer agent [16,[18][19][20][21] or nitroxide-mediated polymerization (NMP) [22] and by atom transfer radical polymerization (ATRP) [23,24]. Several attempts for synthesis of vinyl polymers having triphenylamine as pendant groups, using controlled radical polymerization (NMP [25][26][27][28] and RAFT [29][30][31][32]) or living anionic route [33][34][35][36][37][38][39][40] have been recently reported. However, the controlled radical polymerization of triphenylamine-based (meth) acrylate monomers was less studied until now, only a paper revealing the group transfer polymerization of 4-(dimethylamino)benzyl methacrylate was published [41].…”