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The development of solution-processable semiconducting polymers has brought mankind’s long-sought dream of plastic electronics to fruition. Their potential in the manufacturing of lightweight, flexible yet robust, and biocompatible electronics has spurred their use in organic transistors, photovoltaics, electrochromic devices, batteries, and sensors for wearable electronics. Yet, despite the successful engineering of semiconducting polymers, we do not fully understand their molecular behavior and how it influences their doping (oxidation/reduction) properties. This is especially true for donor-acceptor (D-A) p-systems which have proven to be very efficient at tuning the electronic properties of organic semiconductors. Historically, chain-length dependent studies have been essential in uncovering the relationship between the molecular structure and polymer properties. Discussed here is the systematic investigation of a complete D-A molecular series composed of monodispersed and well-defined conjugated molecules ranging from oligomer (n=3-21) to polymer scale lengths. Structure-property relationships are established between the molecular structure, chain conformation, and redox-active opto-electronic properties for the molecular series in solution. This research reveals a rod-to-coil transition at the 15 unit chain length, or 4500 Da, in solution. The redox-active optical and electronic properties are investigated as a function of increasing chain-length, giving insight into the nature of charge carriers in a D-A conjugated system. This research aids in understanding the solution behavior of conjugated organic materials. <br>

The interest in two-dimensional conjugated polymers (2D CPs) has increased significantly in recent years. In particular, vinylene-linked 2D CPs with fully in-plane sp2-carbon-conjugated structures, high thermal and chemical stability, have become the focus of attention. Although the Horner-Wadsworth-Emmons (HWE) reaction has been recently demonstrated in synthesizing vinylene-linked 2D CPs, it remains largely unexplored due to the challenge in synthesis. In this work, we reveal the control of crystallinity of 2D CPs during the solvothermal synthesis of 2D-poly(phenylene-quinoxaline-vinylene)s (2D-PPQVs) and 2D-poly(phenylene-vinylene)s through the HWE polycondensation. The employment of fluorinated phosphonates and rigid aldehyde building blocks is demonstrated as crucial factors in enhancing the crystallinity of the obtained 2D CPs. Density functional theory (DFT) calculations reveal the critical role of the fluorinated phosphonate in enhancing the reversibility of the (semi)reversible C−C single bond formation.

Mit Lösungen von 9,10-Diphenylanthracen und N(C2H5)4ClO4 oder N(C4H9)4ClO4 als Leitsalz im Lösungsmittel Acetonitril wurden Elektrochemilumineszenz (ECL)-Experimente durchgeführt. Dazu wurden die Elektroden mit Folgen von jeweils drei in bestimmten zeitlichen Abständen aufeinander folgenden Potentialsprüngen polarisiert. Es wird gezeigt, dass bei entsprechender Wahl der Potentiale und der Haltezeiten anodische und kathodische ECL-Emissionen gleicher Intensität erzeugt werden können. Sodann wurde ECL in den Derivaten von Poly(p-phenylen-vinylen), MEH-PPV und DB-PPV erzeugt. Diese leitfähigen Polymere wurden als dünne Schichten auf Platin-Elektroden aufgebracht und wie bei ECL aus der Lösungsphase in Acetonitril-Elektrolyten mit Tetralkylammonium-Leitsalzen Potentialsprüngen unterworfen. Bei geeigneter Einstellung der Potentialsprünge und Haltezeiten konnten anodische und kathodische ECL gleicher Intensität erhalten werden. Dies ist das erste Mal, dass symmetrische ECL mit polymerbeschichteten Elektroden erhalten wurde. Die Kinetik der ECL weicht deutlich von der aus der Lösungsphase ab. Der ECL-Prozess verläuft langsamer als in der Lösungsphase, und der Leitelektrolyt hat einen signifikanten Einfluss auf das elektrochemische Verhalten der Polymerschicht. Die Ursachen dafür wurden über Modellrechnungen analysiert, mit denen die Ladungstransportprozesse in der Polymerschicht simuliert wurden. In derartigen Simulationsrechnungen konnten die Geschwindigkeitskonstanten der ECL-Reaktion sowohl im Polymer als auch in der Lösung bestimmt werden. Um die Stabilität der Polymerschichten zu erhöhen, wurde versucht, die Polymerketten mit Synchrotronstrahlung zu vernetzen. Diese Experimente brachten nicht das erwartete Ergebnis. Die Ursachen dafür werden auf der Grundlage von Ex-Situ-Raman-spektroskopischen Untersuchungen diskutiert. / Electrochemiluminescence (ECL) has been generated in solution phase using 9,10-diphenylanthracene (DPA) with TEAClO4 (or TBAClO4) in acetonitrile solvent. Triple potential step was used for the generation of ECL. It was found that anodic and cathodic ECL of equal intensities can be generated by proper choice of potential step magnitude, width and the waiting period (tw) between successive triple potential steps. ECL was then generated in conducting polymers poly(2-ethylhexyloxy-5-methoxy-1,4-phenylenevinylene) (MEH-PPV) and poly(2,3-dibutoxy-1,4-phenylenevinylene) (DB-PPV) by coating them on Pt electrodes and subjecting to potential steps in tetraalkylammonium salt solutions with acetonitrile. Similar to the case of solution phase ECL, symmetrical anodic and cathodic ECL could be observed by the appropriate choice of the potential step parameters. But the kinetics of the ECL was found to be different from that of the solution phase ECL. The time scale of the ECL process was found to be longer than that in the solution phase ECL. The nature of supporting electrolyte had a remarkable impact on the electrochemistry of conducting polymers. The reasons were analyzed by theoretical calculations evoking the concept of charge transport characteristics of conducting polymers. The rate constants of the ECL process were calculated by separate simulation procedure in the solution phase as well as in the polymer phase ECL. To enhance the stability of conducting polymers, synchrotron radiation induced cross-linking was performed. The effects were different from expected which were analyzed and rationalized by ex-situ Raman spectroscopic studies.

The preparation of a new group of functionalized conjugated polymer networks has been described based on spontaneous quaternization polymerization of ethynylpyridines with bis(bromomethyl)arenes. The networks consisted of polyacetylene chains with pyridyl and pyridiniumyl pendants cross-linked with -CH2(arylene)CH2- links. The variation of the ratio of monomer and quaternization agent in the feed modified the ratio of pyridyl and pyridiniumyl groups in the networks (pyridyl/pyridiniumyl ratios from 0 to 1.32). The networks did not exhibit a permanent microporosity that could be confirmed by nitrogen adsorption at 77 K. Nevertheless, all networks were active in capture of CO2 at 293 K (up to 0.73 mmol CO2/g, 750 Torr). It has been hypothesized that CO2 capture reflected formation of a temporary porous texture of the networks through conformational changes of the network segments enabled by the segments mobility at room temperature. The preparation of functionalized conjugated polymer networks with permanent micro/mesoporosity (SBET up to 667 m2 /g) has been described that was based on chain coordination copolymerization of acetylenic monomers. The copolymerization of 1,4-diethynylbenzene or 4,4'-diethynylbiphenyl with mono or diethynylbenzenes bearing NO2 or CH2OH groups has been demonstrated as...

(Doctoral Thesis, 2016, Mgr. Tomáš Faukner, IONIC POLYACETYLENE TYPE POLYMERS AND POLYMER NETWORKS BY CATALYST FREE QUATERNIZATION POLYMERIZATION) The composition and structure of a series of ionic π-conjugated poly(monosubstituted acetylene)s prepared via catalyst-free quaternization polymerization (QP) of 2-ethynylpyridine (2EP) activated with equimolar amount of alkyl halide [RX = ethyl bromide, ethyl iodide, nonyl bromide and haxadecyl (cetyl) bromide] as a quaternizing agent (QA) have been studied in detail. The performed QPs gave ionic polymers well soluble in polar solvents, with approximately half of pyridine rings quaternized, which implies that also non-quaternized monomers were involved in the process of QP. The configurational structure of polyacetylene main chains was suggested based on 1 H NMR, IR as well as Raman (SERS) spectral methods. The QPs in bulk gave more expected irregular cis/trans polymers while the QPs in acetonitrile solution gave high-cis polymers. A series of prepared symmetrical bi-pyridylacetylene based monomers has been polymerized via QP approach resulting into a series of new ionic π-conjugated poly(disubstituted acetylene) type materials. It is therefore obvious that the mechanism of quaternization activation frequently applied on monosubstituted...

4 ABSTRACT The synthesis has been described yielding a new type of rigid conjugated polymer networks which possess a high content of permanent micropores and macropores and exhibit high surface areas up to 1469 m2/g. The networks have been prepared via chain-growth coordination polymerization catalysed with insertion catalysts based on Rh complexes. This polymerization has been newly applied to bifunctional acetylenic monomers of diethynylarene type (1,4-diethynylbenzene, 1,3-diethynylbenzene and 4,4'-diethynylbiphenyl). The covalent structure of the networks consists of the polyacetylene main chains densely connected by arylene struts. The W and Mo metathesis catalysts have been revealed as inefficient for the synthesis of these networks. The increase in the polymerization temperature and time has been shown to affect positively the content and the diameter (up to 22 nm) of the mesopores in the networks. A mechanism has been proposed that explains the mesopores formation as a result of mutual knitting of small particles of the microporous polymer. The application of emulsion polymerization technique allowed to prepare texturally hierarchical polyacetylene networks possessing interconnected open macropores (diameter up to 4,8 μm) the walls of which exhibited micro/mesoporous texture. It was demonstrated...