Poly(arylenenethynylene)s or PAEs are an interesting class of conjugated polymers that have potential uses in the field of thin film transistors, organic LEDs, sensors, and molecular wires. The field of PAEs have grown in recent years, however very few of its conjugated polymers have a heterocyclic motif contained within them. We have designed some conjugated heterocyclic polymers that contain quinoline, benzothidiazole, and quinoxaline. These polymers show interesting ionochromic and solvochromic effects as well as unusual solid state properties. Some of these polymers will demonstrate their ability to form fascinating nanostructures by use of either mesoporous discs or gold mediated nanotubes. Finally, we also have produced peralkynylated heterocyclic molecules for use in potential n-semiconductive devices. These molecules are not only aesthtically pleasing, but versatile molecules that could be used in conjugated PAEs.

No description available.

Dithienopyrrole-based conjugated materials, including oligomers and polymers, for potential organic electronic applications, were designed, synthesized and characterized. The optical and electrochemical properties of these materials were investigated, and their structure-property relationships were studied. Some of the materials can be oxidized (or reduced) chemically or electrochemically. Furthermore, the utility of these materials in organic electronic devices, such as OFETs and OPVs, were assessed. In OFETs, they can function as hole-transport materials with mobilities up to 4.8 × 10-2 cm2/(Vs), and one example serves as an ambipolar material with comparable hole and electron mobilities of 1.2 × 10-3 and 5.8 ×10-4 cm2/(Vs), respectively. Some of the materials can also be used as electron donors in OPVs in conjunction with PCBM, and exhibited power conversion efficiencies up to 1.4% after optimizations. They may also be used in other applications such as electrochromic devices, photodetectors, and optical limiting.

Interchain interactions between π-systems have a strong effect on the properties of conjugated organic materials that find application in devices such as light emitting diodes (OLEDs), organic photovoltaics (OPVs), and field effect transistors (FETs). We have prepared covalently-stacked oligo(1,4-phenylene ethynylene)s and oligo(1,4-phenylene vinylene)s to study the influence of chain-chain interactions on the electronic structure of closely packed conjugated units. These serve as models for segments of conjugated materials in thin film devices. Extension of this concept has allowed us to prepare multi-tiered systems that display the influence of pi-stacking. The stacked architectures were prepared by multi-step synthesis of the scaffolds, followed by metal-catalyzed cross coupling reactions (Sonogashira, Heck, Suzuki couplings) to incorporate the conjugated oligomers. The optical and electrochemical properties of these stacked compounds and polymers were compared to their unstacked linear counterparts. These studies provide a platform for the exploration of the nature of charge carriers and excitons in a broad class of materials that have significant potential in addressing challenges in power generation, lighting and electronics.

The design of chromophores targets materials with optoelectronic properties necessary for advanced applications. Organic materials possess properties which emerge from the collective impact of the constituent backbone and substituents as well as their connectivity (i.e. molecular architecture), necessitating the exploration of novel conjugated architectures. This thesis chronicles our examination of 1,4-distyryl-2,5-bis(arylethynyl)benzenes (cruciforms, XFs). Electronic substitution of this 'X-shaped' cross-conjugated scaffold tunes both the energy levels and the spatial distribution of the frontier molecular orbitals (FMOs) in XFs. The resulting fluorophores exhibit FMO separation, imbuing XFs with desirable properties for sensory applications. Using model analytes, we examine how the underlying FMO arrangement and the nature of analyte interaction elicit observable responses. These studies provide a foundation for future access of functional responsive ratiometric cores. This case study demonstrates the importance and unique potential of FMO-separated fluorophores.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

Submitted by ANA KARLA PEREIRA RODRIGUES (anakarla_@hotmail.com) on 2017-07-28T12:53:24Z No. of bitstreams: 2 arquivototal.pdf: 4165677 bytes, checksum: cd4f0d6e638890dadcf1bb5f730949a1 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-07-28T12:53:24Z (GMT). No. of bitstreams: 2 arquivototal.pdf: 4165677 bytes, checksum: cd4f0d6e638890dadcf1bb5f730949a1 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-02-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The low molecular weight materials with -conjugated system are widely studied by the academic community and the industry. The properties shown by such systems collaborate are the basis for electro-optical devices such as OLEDs, OFETs and solar cells (organic semiconductors). Liquid crystals compose an important group of low molecular weight materials due to their properties: the order of solid and flow of liquid. In this context, this work presents the synthesis and characterization of the thermal and optical properties of three groups of conjugated compounds derived from benzylidene ketones. The structures of these compound were designed in order to get rod-like structures to form calamitic liquid crystals. The molecules of this work are based on the structure of benzylideneketone 3-methoxy-4-substituted with alkoxyl chains of 4, 10 and 12 carbons. Cyclic and acyclic ketones separate the aromatic rings. The target molecules were characterized by spectrometric methods (IR, 1H and 13C NMR). The thermal properties were investigated by POM, DSC and TGA. One of nine molecules showed mesomorfic phase, three of them did not crystalize on cooling to the room temperature, and the other ones did not show any type of liquid crystalline phase. The thermal decomposition varied from 215 °C to 345 °C. The optical studies were performed in solution by UV spectroscopy. The target compounds exhibited a strong absorption band varying from 330 nm to 370 nm ( = 104 L.mol-1.cm-1) attributed to the -* electronic transitions. / Os materiais de baixa massa molecular com elevada conjugação  são interessantes alvos de pesquisa na academia e na indústria. As propriedades apresentadas por tais sistemas contribuem ativamente na produção de dispositivos eletro-óptico, como OLEDs, OFETs e células solares (semicondutores orgânicos). Os cristais líquidos são uma classe importante de materiais de baixa massa molecular devido às propriedades de ordem do estado sólido e fluidez do estado líquido. Com base neste contexto, este trabalho apresenta a síntese e caracterização das propriedades térmicas e óticas de três séries de compostos conjugados derivados de benzilidenocetonas 3,4-dissubstituídas. As estruturas dessas moléculas foram planejadas a fim de se obter materiais que exibam forma de bastão, requisito básico para a estrutura de cristais líquidos calamíticos. Os compostos sintetizados consistem de dibenzilidenocetonas 3-metoxi-4-substituídas com variadas cadeias alquílicas de 4, 10 e 12 átomos de carbono. Grupos cetonas cíclicos e acíclicos separam os anéis aromáticos. Os compostos foram caracterizados por espectroscopia no Infravermelho, Ressonância Magnética Nuclear de 1H e 13C. As propriedades térmicas foram investigadas através de DSC, MOLP e TGA. Das nove moléculas-alvo sintetizadas, uma apresentou mesomorfismo, três mantiveram estado isotrópico mesmo no resfriamento à temperatura ambiente, e os demais não apresentaram nenhum tipo de mesomorfismo. Os compostos finais apresentaram temperaturas de decomposição na faixa de 215 °C a 345 °C. Os estudos das propriedades óticas foram realizados por Espectroscopia de Ultravioleta em solução. As moléculas sintetizadas apresentaram forte absorção na faixa de 330 nm a 370 nm com elevada absortividade molar ( = 104 L.mol-1.cm-1) que, através de nossos estudos, são atribuídas às transições eletrônicas -*.

No description available.

L'élaboration de réseaux poreux pi-conjugués par l'auto-organisation de molécules organiques, les cyclotriphosphazènes spirocycliques, a été explorée. L'étude de la stabilité des réseaux obtenus à partir du tris(o-phénylènedioxy)cyclotriphosphazène (TPP) conjointement à l'étude de la réactivité du N3P3Cl6 face à l'attaque nucléophile de différents dérivés du catéchol ont permis de définir de nouvelles cibles. Dans ce cadre, un nouveau composé, le tris(2,3-triphénylènedioxy)cyclotriphosphazène (TTPP) dans lequel le motif central est substitué par trois systèmes pi-conjugués étendus de type triphénylène a été synthétisé. Les tectons TTPP, de symétrie C3, présentent une orientation atypique des motifs aromatiques. Leur forme, analogue à celle d'une roue à aubes, leur permet d'engendrer à l'état cristallin des lacunes sous forme de deux types de nano-canaux de respectivement 6,1 Å et 8,4 Å de large et 10,7 Å et 12,4 Å de large, pouvant inclure des molécules de 1,2,4-trichlorobenzène. Ce matériau contient la plus grande porosité obtenu à partir de cyclotriphosphazènes spirocycliques à ce jour. La formation de réseaux poreux chiraux a également été réalisée à partir de tectons portant chacun trois motifs (S)-binol. Le (S,S,S)-tribinolcyclotriphosphazène ((S,S,S)-TBP) a ainsi pu être co-cristallisé avec des molécules d'o-xylène. Ainsi, des informations permettant de mieux comprendre la structure moléculaire de cyclotriphosphazènes portant des spirocycles à sept chaînons ont été obtenues. Enfin, les propriétés optoélectroniques des tectons ont été étudiées en solution. L'influence de l'agent directeur cyclotriphosphazène sur les propriétés optiques des chromophores a, en particulier, été abordée. / Elaboration of pi-conjugated networks through self-organization of spirocyclic cyclotriphosphazene molecules has been explored. The stability of the networks built from described tris(o-phenylenedioxy)cyclotriphosphazene (TPP) jointly with the study of the reactivity of N3P3Cl6 undergoing nucleophilic attack by catechol derivatives allowed to design new tectons. In this context, a new tris(2,3-triphenylenedioxy)cyclotriphosphazene (TTPP) compound embedding a central hub substituted by pi-conjugated triphenylene unit has been synthesized. TTPP tectons exhibits a particular shape with specific orientation of aromatic units. Their paddle-wheel like shape allows the elaboration of a porous network having two types of nano-tunnels of respectively 6.1 Å and 8.4 Å large and 10.7 Å and 12.4 Å large. This material has the biggest channel size described for network build from spirocyclic cyclotriphosphazenes and inclusion compounds with 1,2,4-trich lorobenzene molecules were made. Elaboration of chiral porous network from tectons constituted by three (S)-binol units has also been realized. Tribinolcyclotriphosphazene has been co-cristallized with o-xylene molecules. Thus, useful informations on seven-membered spirocyclic cyclotriphosphazene molecular structure have been obtained. Finally, tectons opto-electronic properties have been studied in solution. Influence of the cyclotriphosphazene directing agent on optical chromophore properties has been a particular matter of attention.

This thesis described the synthesis and characterization of new perylene diimide (PDI)-based photonic and electronic materials. In the first part of this thesis, PDI-based polynorbornenes, including PDI-grafted homopolymers and block-copolymers (BCPs) were synthesized and characterized as alternative acceptors for fullerenes for organic electronics. It was found that the PDIs on the polymer side-chains affect π-π stacking with the neighboring PDIs, which has implications for the use of these materials for organic field-effect transistors (OFETs) and organic photovoltaic devices (OPVs). It should be noted that the performance of solar cell based on these materials was poor, like other similar materials. The major reasons could be the challenge in controlling the molecular alignment of the PDI-based materials, which leads to lower electron mobilities in films compared to devices with fullerene-based acceptors. One PDI-grafted BCP showed better OPV performance compared to the other BCPs and respective homepolymer blends, presumably due to favorable morphology. In the second part of this thesis, photo-induced charge-separation in blends of poly-3-hexyl-thiophene (P3HT) and various PDI derivatives have been studied. Probing of long-lived photo-generated PDI radical anions provided insight on these photo-induced processes and their use for OPVs. In the third part of this thesis, the use of photo-generated PDI radical-anion absorption was shown to be effective for optical limiting of nanosecond laser pulses between 650 - 800 nm. In Chapter 5, an effective approach for two-photon absorption (2PA)-induced optical limiting using donor-PDI dyads through which donors and acceptors can be independently chosen to maximize optical suppression at particular wavelengths has been demonstrated. In Chapter 6, conjugated polymers with PDI pendants and poly(carbazole-alt-2,7-fluorene) main-chains were synthesized for optical limiting using the photo-generated PDI radical anion via PDI aggregate excitation and/or 2PA from the polymer backbones. It was also found that nitro-phenyl group or similar derivatives could be good candidates to incorporate into those donor-conjugated polymers, which have significant overlap between their 2PA band and respective polaron absorptions for 2PA-indced optical limiting. / Thesis advisor has approved the addition of errata to this item. Corrections were made to pages 95, 98 and 101.