Líquidos iônicos (LI) e Poli(líquidos íonicos) (PLI) apresentam propriedades moduláveis extremamente interessantes, devido a possibilidade de infinitas combinações entre cátions e ânions, além da possibilidade de funcionalização tanto do cátion quanto do ânion para a inserção de propriedades de interesse, transformando esses LI e PLI em materiais de tarefa específica (task-LI e task-PLI). Nesta tese de doutorado, um PLI sólido, eletrocrômico e inédito foi sintetizado a partir de um LI funcionalizável e polimerizável (brometo de 1-cloropropil-3-vinilimidazólio) e o viologênio 4,4-bipiridina. Essa reação resultou em um monômero que teve sua estrutura intensamente elucidada e, em seguida, foi polimerizado, formando um polieletrólito sólido eletrocrômico estável mecanicamente e termicamente (309 °C). Os estudos espectroeletroquímicos a partir de um filme fino depositado sobre ITO revelaram um processo redox reversível com redução e oxidação nos potenciais de -0.45 e -0,3 V, respectivamente. O processo redox foi acompanhado por variação de coloração de transparente (estado totalmente oxidado) para roxo (estado reduzido/cátion radical) com contraste ótico de 19 % (525 nm), switching time de 20 s e eficiência da coloração (CE) de 60 cm2 C-1. A estabilidade eletroquímica do filme foi estudada via cronoamperometria e o material permaneceu eletroativo e eletrocrômico por 4 horas e 400 ciclos sem perdas consideráveis de eletroatividade. Além disso, mesmo após 16 h e 1600 ciclos o material apresentou eletroatividade com um decréscimo pequeno de corrente e variação de transmitância. Adicionalmente, o monitoramento do material com uma microbalança a cristal de quartzo com dissipação (QCM-D) indicaram que a compensação de carga do polímero é acompanhada por uma considerável variação de viscoelasticidade do filme e a principal espécie responsável pela compensação é o ânion, sendo o ânion volumoso [Tf2N] incapaz de compensar a carga do sistema impedindo o processo redox de ocorrer. Ainda com relação a capacidade de funcionalização dos LI, um LI inédito foi preparado a partir de um segundo LI funcionalizável (brometo de 1-cloropropil-1-metilpirrolidíneo) que foi elucidado por diversas técnicas incluindo ressonância magnética nuclear em duas dimensões de 1H, 13C e 15N (RMN 2D: COSY, NOESY, HSQC e HMBC) e RMN 15N. Dessa forma, um LI funcionalizado com aza-éter de coroa (LIcoroa) foi preparado a partir da reação do LI funcionalizável e o aza-18-coroa-6 e, novamente, a estrutura foi elucidada, incluindo RMN 2D. O LIcoroa apresentou boa estabilidade térmica (371 °C) e eletroquímica (janela de 4 V). A densidade do LI foi obtida no valor de 1,5 g cm-3 (25 °C). No entanto, a viscosidade do LI foi elevada afetando diretamente sua condutividade elétrica quando comparado com o LI bis(trifluorosulfonil)imida de 1-bultil-1-metilpirrolidíneo já amplamente estudado na literatura. Para aplicações, este LI coroa está sendo estudado para atuar como eletrólito em baterias de íon lítio devido a sua possível capacidade de complexar com este íon e diminuir a interação do Li+ com os oxigênios da espécie aniônica [Tf2N]. / Ionic Liquids (ILs) and poly(Ionic Liquids) (PoILs) have fully tunable properties due to their different ion combinations as well as cation or anion functionalization, which results in smart materials with endless possibilities. In this study, a solid electrochromic PoIL was synthesized using a novel functionalizable and polymerizable IL (1-propyl-3-vinylimidazolium chloride bromide) and a viologen (4,4\'-bipyridine) that reacted to form a monomer. Its subsequent polymerization resulted in a mechanically stable, highly ionically and electronically conductive electrochromic polyelectrolyte with a thermal decomposition temperature higher than 309°C and a glass transition temperature of 13°C. Spectroelectrochemical studies of the polymer deposited as a thin film over a transparent conductive substrate demonstrated a reversible redox process with reduction and oxidation potentials of -0.45 and -0.3V, respectively, which was accompanied by a reversible color change from colorless (oxidized state) to purple (reduced state) with an optical contrast of 19% at 525nm, a switching time of nearly 20s and a coloration efficiency of 60 cm2 C-1. Additionally, the film was repetitively switched from colorless to purple and began to lose electroactivity after approximately 4h and 400cycles. However, electroactivity was still observed after 16h or 1600cycles. Moreover, quartz crystal microbalance with dissipation monitoring indicated that the polymer charge compensation process was accompanied by a huge viscoelastic change in the film, as demonstrated by the spread of the harmonics and important changes in dissipation. Moreover, the anion is the most important specie in the charge compensation process, the large anion [Tf2N] is unable to compensate the charge, preventing the redox process from occurring. Also regarding the functionalization capacity of LI, a novel LI was prepared from a second functionalizable LI (1-chloropropyl-1-methylpyrrolidinium bromide) which was intensively elucidated by several techniques including two-dimensional nuclear magnetic resonance 1H, 13C and 15N (2D NMR: COSY, NOESY, HSQC and HMBC). Thus, a functionalized LI with aza-crown ether (LIcrown) was prepared from the reaction of the functionalizable LI and aza-18-crown-6 and, again, the structure was elucidated, including 2D NMR. LIcrown presented good thermal stability (371 ° C) and electrochemistry (4 V window). The density of the IL was 1,5 g cm-3. However, the viscosity of the LI was elevated by directly affecting its electrical conductivity when compared to the 1-butyl-1-methylpyrrolidinium bis(trifluorosulfonyl)imide already widely studied in the literature. For applications, this LIcrown is being studied to act as an electrolyte in lithium ion batteries because of its possible ability to complex with this ion and to decrease the interaction of Li+ with the oxygen of the anionic species [Tf2N].

This thesis deals with the design of ligands for efficientasymmetric catalysis and studies of the conformation of theligands in the catalytically active complexes. All ligandsdeveloped contain chiral oxazoline heterocycles. The conformations of hydroxy- and methoxy-substitutedpyridinooxazolines and bis(oxazolines) during Pd-catalysedallylic alkylations were investigated using crystallography,2D-NMR techniques and DFT calculations. A stabilising OH-Pdinteraction was discovered which might explain the differencein reactivity between the hydroxy- and methoxy-containingligands. The conformational change in the ligands due to thisinteraction may explain the different selectivities observed inthe catalytic reaction. Polymer-bound pyridinooxazolines and bis(oxazolines) weresynthesised and employed in Pd-catalysed allylic alkylationswith results similar to those of monomeric analogues;enantioselectivities up to 95% were obtained. One polymer-boundligand could be re-used several times after removal of Pd(0).The polymer-bound bis(oxazoline) was also used in Zn-catalysedDiels-Alder reactions, but the heterogenised catalyst gavelower selectivities than a monomeric analogue. A series of chiral dendron-containing pyridinooxazolines andbis(oxazolines) were synthesised and evaluated in Pd-catalysedallylic alkylations. The dendrons did not seem to have anyinfluence on the selectivity and little influence on the yieldwhen introduced in the pyridinooxazoline ligands. In thebis(oxazoline) series lower generation dendrimers had a postiveon the selectivity, but the selectivity and the activitydecreased with increasing generation. Crown ether-containing ligands were investigated inpalladium-catalysed alkylations. No evidence of a possibleinteraction between the metal in the crown ether and thenucleophile was discovered. A new type of catalyst, an oxazoline-containing palladacyclewas found to be very active in oxidations of secondary alcoholsto the corresponding aldehydes or ketones. The reactions wereperformed with air as the re-oxidant. Therefore, this is anenviromentally friendly oxidation method. <b>Keywords:</b>asymmetric catalysis, chiral ligand,oxazolines, conformational study, allylic substitution,polymer-bound ligands, dendritic ligands, crown ether,oxidations, palladacycle.

<p>This thesis deals with the design of ligands for efficientasymmetric catalysis and studies of the conformation of theligands in the catalytically active complexes. All ligandsdeveloped contain chiral oxazoline heterocycles.</p><p>The conformations of hydroxy- and methoxy-substitutedpyridinooxazolines and bis(oxazolines) during Pd-catalysedallylic alkylations were investigated using crystallography,2D-NMR techniques and DFT calculations. A stabilising OH-Pdinteraction was discovered which might explain the differencein reactivity between the hydroxy- and methoxy-containingligands. The conformational change in the ligands due to thisinteraction may explain the different selectivities observed inthe catalytic reaction.</p><p>Polymer-bound pyridinooxazolines and bis(oxazolines) weresynthesised and employed in Pd-catalysed allylic alkylationswith results similar to those of monomeric analogues;enantioselectivities up to 95% were obtained. One polymer-boundligand could be re-used several times after removal of Pd(0).The polymer-bound bis(oxazoline) was also used in Zn-catalysedDiels-Alder reactions, but the heterogenised catalyst gavelower selectivities than a monomeric analogue.</p><p>A series of chiral dendron-containing pyridinooxazolines andbis(oxazolines) were synthesised and evaluated in Pd-catalysedallylic alkylations. The dendrons did not seem to have anyinfluence on the selectivity and little influence on the yieldwhen introduced in the pyridinooxazoline ligands. In thebis(oxazoline) series lower generation dendrimers had a postiveon the selectivity, but the selectivity and the activitydecreased with increasing generation.</p><p>Crown ether-containing ligands were investigated inpalladium-catalysed alkylations. No evidence of a possibleinteraction between the metal in the crown ether and thenucleophile was discovered.</p><p>A new type of catalyst, an oxazoline-containing palladacyclewas found to be very active in oxidations of secondary alcoholsto the corresponding aldehydes or ketones. The reactions wereperformed with air as the re-oxidant. Therefore, this is anenviromentally friendly oxidation method.</p><p><b>Keywords:</b>asymmetric catalysis, chiral ligand,oxazolines, conformational study, allylic substitution,polymer-bound ligands, dendritic ligands, crown ether,oxidations, palladacycle.</p>

Supramolecular host-guest chemistry is a topic of great current interest. However, the further development of host-guest chemistry is still limited by the number of available host-guest recognition motifs. This makes it necessary and valuable to find new host-guest recognition motifs and apply known host-guest recognition motifs in the preparation of novel supramolecular systems. By comparing the crystal structures of the host and its taco complex, we proved that folding is a necessary step during the formation of taco complexes. Based on the known bis(m-phenylene)-32-crown-10/paraquat recognition motif, the first solid-state supramolecular poly(taco complex) was prepared. We demonstrate not only that bis(m-phenylene)-32-crown-10-based cryptands are powerful hosts for paraquat derivatives compared with the simple crown ether, but also that cooperative complexation can be obtained with the cryptand structure. It was shown that the significant improvement in complexation was the result of the combination of the preorganization of the cryptand hosts and the introduction of additional and optimized binding sites. Furthermore, it was demonstrated that improved complexation of bis(secondary ammonium) and bisparaquat salts could also be achieved by the formation of the pseudocryptand structure. We also prepared two dimers of inclusion cryptand/paraquat complexes driven by dipole-dipole and face-to-face p-stacking interactions. An interesting complex based on dibenzo-24-crown-10 and diquat was prepared. In its crystal structure the diquat guest lies in the concave cavity provided by two dibenzo-24-crown-8 hosts. Monopyridinium-based [2]- and [3]-pseudorotaxanes were prepared based on the newly discovered bis(m-phenylene)-32-crown-10/monopyridinium salt and cryptand/monopyridinium salt recognition motifs. Inspired by the formation of solid-state taco complexes between bis(m-phenylene)-32-crown-10 and paraquat derivatives, we designed and synthesized the first cylindrical bis(crown ether) host for paraquat derivatives and studied its complexation with paraquat. We prepared three slow-exchange C3-symmetric inclusion complexes based on a newly discovered cryptand/trispyridinium recognition motif, in which 1,3,5-trispyridiniumbenzene salts act as guests. Finally the application of several new and known recognition motifs in the preparation of a supramolecular poly[3]pseudrotaxane, and the first pseudorotaxane-type supramolecular star-shaped polymer, and the first supramolecular hyperbranched polymer was discussed. / Ph. D.

This thesis deals with the design and syntheses of chiral,enantiopure pyridinecontaining ligands and their applicationsin asymmetric catalyis. Chiral pyridyl pyrrolidine ligands and pyridyl oxazolineligands were synthesized and employed in thepalladium-catalysed allylic alkylation of 1,3-diphenyl-2-propenyl acetate with dimethyl malonate. Theinfluence of the steric properties of the ligands wereinvestigated. Ditopic ligands, containing crown ether units as structuralelements, were synthesized and some of the ligands were used asligands in the palladiumcatalysed allylic alkylation of1,3-diphenyl-2-propenyl acetate with dimethyl malonate. A smallrate enhancement was observed, compared with analogous ligandslacking the crown ether unit, when these ditopic ligands wereused in dilute systems. A modular approach was used to synthesize chiralenantiomerically pure pyridyl alcohols and C2-symmetric2,2’-bipyridines, with the chirality originating from thechiral pool. Electronic and steric properties of the compoundswere varied and they were used as ligands in theenantioselective addition of diethylzinc to benzaldehyde. Thesense of asymmetric induction was found to be determined by theabsolute configuration of the carbinol carbon atom. Theelectronic properties of the ligands had a minor influence onthe levels of enantioselectivity induced by the ligands. Chiral pyridyl phosphinite ligands and pyridyl phosphiteligands were synthesized from the pyridyl alcohols andevaluated as ligands in palladiumcatalysed allylic alkylations.With the phosphinite ligands, the sense of chiral induction wasfound to be determined by the absolute configuration of theformer carbinol carbon atom. A kinetic resolution of theracemic starting material was observed with one of thephosphite ligands. Moderate enantioselectivities wereachieved. <b>Kewords:</b>asymmetric catalysis, chiral ligand, chiralpool, oxazoline, crownether, ditopic receptor, bipyridine,pyridyl alcohol, modular approach, P,Nligand, diethylzinc,allylic alkylation.

A new class of &pi / -conjugated monomers was synthesized with combination of electron donating and electron-withdrawing heterocyclics to understand the effects of structural differences on electrochemical and optoelectronic properties of the resulting polymers. Electron deficient benzotriazole, substititued with benzyl from two available sites, coupled with stannylated electron donating groups, ethylenedioxythiophene (EDOT) and thiophene (Th), to yield four different monomers / 1-benzyl-4,7-di(thiophen-2-yl))-2H-benzo[d][1,2,3] triazole (BBTA), 2-benzyl-4,7-di(thiophen-2-yl))-2H-benzo[d][1,2,3] triazole (BBTS), 1-benzyl-4,7-bis(2,3-dihydrothieno[3,4-b]dioxin-5-yl)-2H-benzo [d][1,2,3]triazole (BBTEA), 2-benzyl-4,7-bis(2,3-dihydrothieno[3,4-b]dioxin-5-yl)-2H-benzo [d][1,2,3]triazole (BBTES). Furthermore, EDOT and thiophene terminated napthalene-2,3-crown ether containing monomers, 14,19-di(thiophen-2-yl)-naphtho[2,3-b][1,4,7,10,13] pentaoxacyclo pentadecane (TNCT), 14,19-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-naphtho[2,3-b][1,4,7,10,13]pentaoxacyclopenta decane (ENCE), were synthesized to observe the effect crown ether moiety on the final electrochemical and optoelectronic properties of resultant polymers. Cyclic voltammetry, UV-Vis-NIR spectroscopy and colorimetry techniques were employed to examine electrochemical and optoelectronic properties of all monomers and polymers. Experimental results showed that alteration of substituent, substitution position and donor groups&rsquo / strength lead to obtain polymers with different redox behaviors, optical band gaps and different number of achievable colored states.

<p>This thesis deals with the design and syntheses of chiral,enantiopure pyridinecontaining ligands and their applicationsin asymmetric catalyis.</p><p>Chiral pyridyl pyrrolidine ligands and pyridyl oxazolineligands were synthesized and employed in thepalladium-catalysed allylic alkylation of 1,3-diphenyl-2-propenyl acetate with dimethyl malonate. Theinfluence of the steric properties of the ligands wereinvestigated.</p><p>Ditopic ligands, containing crown ether units as structuralelements, were synthesized and some of the ligands were used asligands in the palladiumcatalysed allylic alkylation of1,3-diphenyl-2-propenyl acetate with dimethyl malonate. A smallrate enhancement was observed, compared with analogous ligandslacking the crown ether unit, when these ditopic ligands wereused in dilute systems.</p><p>A modular approach was used to synthesize chiralenantiomerically pure pyridyl alcohols and C2-symmetric2,2’-bipyridines, with the chirality originating from thechiral pool. Electronic and steric properties of the compoundswere varied and they were used as ligands in theenantioselective addition of diethylzinc to benzaldehyde. Thesense of asymmetric induction was found to be determined by theabsolute configuration of the carbinol carbon atom. Theelectronic properties of the ligands had a minor influence onthe levels of enantioselectivity induced by the ligands.</p><p>Chiral pyridyl phosphinite ligands and pyridyl phosphiteligands were synthesized from the pyridyl alcohols andevaluated as ligands in palladiumcatalysed allylic alkylations.With the phosphinite ligands, the sense of chiral induction wasfound to be determined by the absolute configuration of theformer carbinol carbon atom. A kinetic resolution of theracemic starting material was observed with one of thephosphite ligands. Moderate enantioselectivities wereachieved.</p><p><b>Kewords:</b>asymmetric catalysis, chiral ligand, chiralpool, oxazoline, crownether, ditopic receptor, bipyridine,pyridyl alcohol, modular approach, P,Nligand, diethylzinc,allylic alkylation.</p>

Natural products have been demonstrated to be of great significance to the pharmaceutical industry in the development of new drugs and medicine. Unfortunately, synthetic approaches to obtain these natural products often prove increasingly challenging due to the complexity of synthesizing the target drug in the proper stereochemistry. The availability of enantioselective reactions can play a pivotal role in overcoming this challenge, yielding access to optically pure intermediates and products. Chiral ligands based on a trans-1,2-diaminocyclohexane motif are often employed for this purpose and their complexes with transition metals have been demonstrated to act as efficient chiral catalysts in asymmetric reactions. In contrast, studies involving cis-1,2-diaminocyclohexane derivatives as chiral catalysts are strongly underrepresented. We have designed and performed the synthesis of an axially chiral conformationally locked cis-1,2-diamine scaffold, conveniently designed for further derivatization into more complex structures. A key step in this synthesis was the chiral resolution of a racemic intermediate, realized through both chemical and enzymatic means in a comparative study. Utilizing the newly gained optically pure primary diamine scaffold, a library of chemically diverse secondary diamine ligands has been synthesized and characterized through NMR spectroscopy, mass spectrometry, and chiral HPLC. Assignment of the absolute configuration within the cis-1,2-diamine scaffold was realized through single-crystal X-ray crystallography experiments on one of the synthetic intermediates. The synthesized ligands have been evaluated for their potential to function as chiral catalysts in the asymmetric Henry reaction and asymmetric transfer hydrogenation. As a function of both steric and electronic structural variation, a range of catalytic activities and enantioselectivities in the Henry reaction were observed. The ligands proved to be less suitable for asymmetric transfer hydrogenation with only a select number of ligands catalyzing the reaction, and a single example resulting in a decent enantioselectivity. We additionally explored the possibility of incorporating a chemical switch into the scaffold, responsible for switching the axial chirality of the molecule. As a consequence of inverting the axial chirality, the configuration of the potential reaction product in asymmetric synthesis would also be inverted. To this extent, we performed the synthesis of a novel specifically designed crown ether, dicyclohexeno-18-crown-6, furnished with two π-bonds in the cyclohexane rings, allowing for additional modification into more advanced functionalized structures.

No description available.

Design and preparation of novel host/guest systems, such as pseudorotaxanes, semirotaxanes, rotaxanes and catenanes, with high association constants, enhanced yields and the abilities to respond to external stimuli are of great importance and significance due to their topological novelty and potential application. The convergence of supramolecular chemistry with polymer science provides an important way to extend the scope of polymer and material sciences by incorporating designed host/guest systems into polymers, and the resulting non-covalently linked supramolecular polymers are expected to have unusual properties due to their unique architectures compared with traditional polymers. After discovery of bis(meta-phenylene)-32-crown-10 (BMP32C10) derivative/paraquat complexes, for about a quarter century only “taco”-shaped complexes were observed by X-ray crystallography. Here, by the self-assembly of a BMP32C10 bearing two electron-donating groups (carbazoles) with electron-accepting paraquat derivatives, the first [2]pseudorotaxane and the first pseudocryptand-type poly[2]pseudorotaxane based on BMP32C10 were isolated as crystalline solids as shown by X-ray analyses. The first dual component pseudocryptand-type [2]pseudorotaxanes were designed and prepared via the self-assembly of synthetically easily accessible BMP32C10 pyridyl, quinolyl and naphthyridyl derivatives with paraquat. The formation of the pseudocryptand structures in the complexes remarkably improved the association constants by forming the third pseudo-bridge via H-bonding with the guest and π-stacking of the heterocyclic units. A pseudocryptand-type [2]pseudorotaxane was formed via the self-assembly of a dipyridyl BMP32C10 derivative and a paraquat derivative. Due to the basicity of the pyridyl group, which forms the third pseudo-bridge of the pseudocryptand, this pseudorotaxane represents the first system with acid-base adjustable association constants, i. e., finite both under acidic and neutral conditions. The first pseudocryptand-type supramolecular [3]pseudorotaxane was designed and prepared via the self-assembly of a bispicolinate BMP32C10 derivative and a bisparaquat. The complexation behavior was cooperative. In addition, the complex comprised of the BMP32C10 derivative and a cyclic bisparaquat demonstrated strong binding; interestingly, a poly[2]pseudocatenane structure was formed in the solid state for the first time. Two novel BMP32C10 cryptands, bearing covalent and metal complex linkages, were designed and prepared. By employing the self-assembly of these biscryptands, which can be viewed as AA monomers, and a bisparaquat, which can be viewed as a BB monomer, the first AA/BB-type linear supramolecular polymers with relatively high molecular weights were successfully prepared. Via the self-assembly of two BMP32C10-based cryptands, bearing covalent and metal complex (ferrocene) linkages, with dimethyl paraquat, novel [3]pseudorotaxanes were formed statistically and anticooperatively, respectively. From a hydroxyl-functionalized secondary ammonium salt a [2]semirotaxane and a [2]rotaxane were prepared successfully with dibenzo-24-crown-8 (DB24C8). X-ray analysis of a single crystal of the [2]semirotaxane confirmed its semirotaxane nature. In addition, the formation of the [2]semirotaxane can be reversibly controlled by adding KPF6 and 18C6 sequentially. This system affords a way to prepare novel supramolecular polymers. Dibenzo-30-crown-10 (DB30C10) derivatives and pyridine-based DB30C10 cryptands were prepared by employing the templating method established by our group. A [2]pseudorotaxane was prepared based on DB30C10 diol and paraquat diol. The [3]pseudorotaxane formed via the self-assembly between DB30C10 cryptand and bisparaquat diol occurred in a cooperative manner. In addition, a bromo-functionalized DB30C10 cryptand was successfully designed and prepared. An alkyne-functionalized DB30C10 cryptand was designed and is under preparation; its precursors have been prepared successfully. In the future, based on these functionalized cryptands and paraquat salts, AA and AB type monomers will be prepared. Via the self-assembly between these monomers, non-covalent supramolecular polymers with high molecular weight will be afforded. A novel DB30C10 cryptand bearing an organometallic bridge, ferrocene, was prepared via 1-(3'-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI) coupling of the crown ether diol with ferrocene dicarboxylic acid. The cryptand is dimerized in the solid state via π, π-stacking and hydrogen bonds. The ferrocene-based cryptand formed novel [2]pseudorotaxanes with paraquat and diquat PF₆ salts with association constants (Kₐ) of 1.7 ± 0.1 x 10³ and 4.2 ± 0.3 x 10⁴ M⁻¹ in acetone-d₆, respectively. In order to prepare linear polycatenanes, the preparation of which represent a real synthetic challenge, a series phenanthroline derivatives were designed and prepared. A “U” shaped monomer was successfully prepared in relative high yield with good solubility. In the future, real linear polycatenanes will be prepared. In addition, a novel diphenanthroline-based BMP32C10 derivative was prepared in high yield and the complexation behavior between it and dimethyl paraquat was studied. / Ph. D.