Polímeros de coordenação têm atraído a atenção de pesquisadores na última década por conta de sua incrível versatilidade e virtualmente infinito número de possibilidades de combinação de ligantes orgânicos e centros metálicos. Estes compostos normalmente herdam as características magnéticas, eletrônicas e espectroscópicas de seus componentes base. Entretanto, apesar do crescente número de trabalhos na área, ainda são raros os polímeros de coordenação que apresentem condutividade elétrica. Para este fim, utilizou-se a N,N\'-bis(4-piridil)-1,4,5,8-naftaleno diimida, ou NDI-py, que pertence a uma classe de compostos rígidos, planares, quimicamente e termicamente estáveis e que já foram extensamente estudados por suas propriedades fotoeletroquímicas e semicondução do tipo n. O primeiro polímero de coordenação sintetizado, MOF-CoNDI-py-1, indicou ser um polímero linear, de estrutura 1D. O segundo, MOF-CoNDI-py-2, que conta com ácido tereftálico como ligante suporte, é um sólido cristalino com cela unitária monoclínica pertencente ao grupo espacial C2/c, determinado por difração de raios-X de monocristal. A rede apresenta um arranjo trinuclear de íons Co(II) alto spin com coordenados em uma geometria de octaedro distorcido, enquanto os ligantes NDI-py se encontram em um arranjo paralelo na estrutura, em distâncias apropriadas para transferência eletrônica. Com o auxílio de cálculo teóricos a nível de DFT, foi realizado um estudo aprofundado dos espectros eletrônicos e vibracionais, com atribuição das transições observadas, tanto para o MOF-CoNDI-py-2 quanto para o ligante NDI-py livre. A rede de coordenação absorve em toda a região do espectro eletrônico analisada, de 200 nm a 2500 nm, além de apresentar luminescência com característica do ligante. Dispositivos eletrônicos fabricados com um cristal do MOF-CoNDI-py-2 revelaram condutividades da ordem de 7,9 10-3 S cm -1, a maior já observada para um MOF. Além de elevada, a condutividade elétrica dos cristais demonstrou-se altamente anisotrópica, sendo significativamente menos condutor em algumas direções. Os perfis de corrente versus voltagem foram analisados em termos de mecanismos de condutividade, sendo melhores descritos por um mecanismo limitado pelo eletrodo to tipo Space-Charge Limited Current, concordando com a proposta de condutividade através dos planos de NDI-py na rede. A condutividade dos cristais também é fortemente dependente de luz, apresentando fotocondução quando irradiado por um laser vermelho, de 632 nm, enquanto apresenta um comportamento fotorresistivo frente a uma fonte de luz branca. Estes resultados, combinados, trazem um MOF em uma estrutura incomum e com elevada condutividade elétrica, modulada por luz, em medidas diretas de corrente. Não existem exemplos conhecidos de MOFs na literatura com estas características. / Coordination polymers have been a major topic in materials science during the past decade, thanks to their versatility and virtually infinite possible combinations between metal centers and organic ligands. These coordination polymers usually inherit the properties of their components, such as magnetic, spectroscopic and electronic characteristics. However, despite the increasing number of research papers in this topic, it is still hard to find coordination polymers featuring electronic conductivity. To achieve that, we used a naphthalene diimide derivative, N,N\'-bis(4-pyridyl)-1,4,5,8- naphthalene diimide or NDI-py, which belongs to a class of rigid, planar, thermally and chemically stable compounds, extensively studied due to their photoelectrochemical properties and their n-type semiconductivity. The first coordination polymer synthesised, MOF-CoNDI-py-1, was an amorphous linear polymer, with a 1D structure. Based on these observations, MOF-CoNDI-py-2 was synthesised by using terephthalic acid as a supporting ligand, and it is a crystalline solid which its monoclinic unit cell belongs to a C2/c space group, as determined by single crystal X-ray diffraction. This network features a trinuclear high-spin Co(II) unit, and each metal ion sits on a distorted octahedra coordination geometry, while the NDI-py ligands sit in a parallel arrangement, with distances suitable for electronic transfers. A detailed study of their vibrational and electronic spectra, supported by DFT calculations, was performed, as well as a full description and assignment of the observed bands. MOF-CoNDI-py-2 absorbs in the whole studied spectral region, from 200 nm to 2500 nm, while it also features a ligand-centered emission spectrum. Electronic devices built around its crystals revealed electric conductivities of 7.9 10 -3 S cm -1, which is, to the best of our knowledge, the highest for a MOF to this date. This conductivity is also highly anisotropic, being significantly less conductive in certain directions. The current versus voltage profiles were analysed in terms of known conduction mechanisms, with best fits when using an electrode-limited Space-Charge Limited Current mechanism, in agreement with the proposition that this conductivity happens through the NDI-py stacking planes. Additionally, this mechanism is influenced by an external light source, being a photoconductor with a red laser, 632 nm, and a photoresistor with a white light. Combined, these results bring a light-modulated, highly conductive MOF material with an unusual structure. As far as we know, there are no similar MOFs in the literature, which makes MOF-CoNDI-py-2 one of a kind.

O naftaleno é um dos principais constituintes do petróleo solúvel em água e esta classe de poluentes está enquadrada na lista prioritária de contaminantes orgânicos persistentes. O presente trabalho traz informações sobre o efeito do naftaleno em ensaios ecotoxicológicos com quatro diferentes grupos de organismos aquáticos. Ensaios crônicos com a microalga marinha Dunaliella tertiolecta e com ouriço-do-mar Lytechinus variegatus, ensaios crônicos e agudos com o copépodo estuarino bentônico Nitokra sp e ensaios agudos com o anfípodo estuarino Leptocherius plumulosus. Na avaliação do efeito crônico, o valor médio da CI(I)50-96h encontrada para microalga marinha foi de 29,01 mg.L-1 e o valor médio da CE(I)50-24h para ouriço-do-mar foi de 0,30 mg.L-1. Para o copépodo, os ensaios crônicos tiveram os valores de 0,19 mg.L-1 para CENO(I) e 0,40 mg.L-1 para CEO(I). Nos ensaios agudos, este mesmo organismo apresentou uma média de CL(I)50-96h em 13,4 mg.L-1 e a média da CL(I)50-96h para o anfípodo estuarino foi de 2,38 mg.L-1. Estes resultados evidenciam potenciais de efeito para diferentes classes de organismos aquáticos e poderão auxiliar nas avaliações ambientais, quando houver limites disponíveis e diretrizes que estabeleçam condições e padrões de lançamento de efluentes nos corpos de água no Brasil. / Naphthalene is a major constituent of the oil soluble in water and this class of pollutants is framed in the priority list of persistent organic pollutants. The present study provides information on the effect of naphthalene in ecotoxicological tests with four different groups of aquatic organisms. Chronic tests with the marine microalgae Dunaliella tertiolecta and sea-urchin Lytechinus variegatus, acute and chronic tests with the estuarine benthic copepod Nitokra sp and acute tests with the estuarine amphipod Leptocheirus plumulosus. In the assessment of chronic effect, the average value of IC(I)50-96h to marine microalgae was 29.01 mg.L-1 and the mean EC(I)50-24h for sea urchin 0.30 mg.L-1. In chronic tests for estuarine copepod the obtained values to NOEC and OEC was ranged from 0.19 mg L-1 to 0.40 mg L-1. In acute tests the same organism have showed an average of LC(I)50-96h in 13.4 mg.L-1 and for the estuarine amphipod the mean LC(I)50-96h was 2.38 mg.L-1. These results demonstrate the potential effect on different classes of aquatic organisms. This may assist in environmental assessments in Brazil, when limits and guidelines are available and allow establishing conditions and standards of effluent discharge into water bodies in Brazil.

Les réactions multicomposantes jouent un rôle important en chimie organique. Ce sont des réactions qui mettent en jeu au moins trois réactifs de départ et qui permettent d’obtenir des produits considérés comme des éléments intéressants pour la synthèse de molécules complexes ou de composés bioactifs. Grâce à leur versatilité, ces réactions sont considérées comme des outils précieux pour la préparation de bibliothèques de composés organiques dans le domaine de la recherche pharmaceutique et de la synthèse de produits naturels.La réaction de Passerini, combinée à une addition de Michael et à une cyclisation, a permis un accès facile à des γ-butyrolactones avec de bons rendements. Les adduits de Passerini issus d’aldéhydes aromatiques ont été utilisés comme nucléophiles lors d’additions de Michael avec l'acrylonitrile. La réaction s’est déroulée conjointement avec l'hydrolyse de l'ester. Les γ-hydroxynitriles résultant ont pu être cyclisés dans des conditions acides pour former des γ-butyrolactones.Les NH-aryl hydrazones dérivées du trifluoroacétaldéhyde hémiacétal ont pu être impliquées dans des réactions de type Mannich efficaces avec le formaldéhyde et des aldéhydes aromatiques. Les hydrazones résultantes sont des blocs de construction utiles pour la préparation de dérivés 1,2-diazine substitués par un groupement trifluorométhyle sous chauffage avec des β-cetoesters.Enfin, des dérivés naphtalèniques ont pu être obtenus par une réaction de Tsuji-Trost. Le méchanisme de cette réaction passe par la formation d'un complexe -allylique de palladium suivi d'une élimination d’hydrure en  favorisée par une base. Cette réaction, combinée avec la condensation de cétones cycliques avec le nitrométhane et la fonctionnalisation des nitrocycloalcènes résultants (Michael, Mannich ...), constituent un outil synthétique très puissant pour la synthèse de naphtalènes 1-substitués. / Multicomponent reactions play a significant role in organic chemistry. They allow the reaction occur between three or more starting materials, providing adducts which are considered as elements for the syntheses of complex molecules with bioactive compounds. Benifiting from their diversity, these reactions are considered as valuable tools for the preparation of libraries of organic structures in the pharmaceutical research and total synthesis of natural products field.The Passerini reaction, combined with Michael addition and cyclisation, served an easy access to γ-butyrolactones with good yields. The Passerini adducts of aromatic aldehydes act as nucleophiles in Michael additions with acrylonitrile. The reaction proceeds together with hydrolysis of the ester. The resulting γ-hydroxynitrile can be cyclized under acidic conditions to afford γ- butyrolactones.The NH-aryl hydrazones derived from trifluoroacetaldehyde hemiacetal can be involved in efficient Mannich type reactions with formaldehyde and aromatic aldehydes. The resulting hydrazones are useful building blocks for the preparation of trifluoromethyl substituted 1,2-diazine derivatives under heating with β-ketoesters.Moreover, naphthalene derivatives may be obtained through Tsuji-Trost reaction. This reaction may involve the formation of a palladium p-allyl complex followed by a base promoted β-hydride elimination. This reaction combined with the condensation of fused cyclic ketones with nitromethane and the functionalization of the resulting nitrocycloalkenes (Michael, Mannich...) constitute a very powerful synthetic tool for the formation of 1-substituted naphtalenes.

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The stable free radical polymerization methodology for production of controlled macromolecules was investigated using a novel monomer, 2-vinylnaphthalene. Initial polymerizations resulted in molecular weight distributions typical of conventional free radical polymerization techniques (>2.0). Manipulation of the initiator concentration and the molar ratio of initiator to nitroxide demonstrated no significant control over the resulting polymer products. Analysis of the polymerization kinetics for a 2-vinylnaphthalene polymerization performed in the presence and absence of the free radical initiator revealed identical monomer consumption profiles as well as pseudo first order kinetics indicating a significant degree of the thermal polymerization was occurring at the polymerization temperature (130°C). Comparison of the thermal polymerization propensity of 2-vinylnaphthalene and styrene revealed an increased tendency for 2-vinylnapthahlene to undergo thermal polymerization. Styrene is considered highly active in its propensity to thermally polymerize. However, an Arhenius analysis using in situ FTIR was employed to determine the activation energy for the thermal polymerization of styrene and 2-vinylnaphthalene. The 2-vinylnaphthalene activation energy for thermal polymerization was determined for the first time to be almost 30 kJ/mol less than styrene. A novel modified Mayo mechanism was proposed for the 2-vinylnaphthalene thermal initiation mechanism. Moreover, this thermal initiation was employed to initiate nitroxide mediated polymerizations of styrene. This first use of a 2-vinylnaphthalene initiating system resulted in polystyrene with a large macrocyclic initiating fragment. The presence of the initiating moiety was studied using both UV-Vis spectroscopy and 1H NMR spectroscopy. The extension of stable free radical polymerization to the acrylate monomer family was examined using a novel nitroxide mediator, N-tert-butyl-N-[1-diethylphosphono-(2,2-dimethylpropyl)] nitroxide (DEPN). The synthesis of DEPN was monitored using in situ FTIR spectroscopy to determine optimum reaction conditions. The purified nitroxide was subsequently employed in the synthesis of various block and random acrylate copolymers. The production of a unique amphiphilic block copolymer consisting of acrylic sequences was achieved. Poly(t-butyl acrylate-b-2ethylhexyl acrylate-b-t-butyl acrylate) was synthesized using the SFRP process. The t-butyl functionalities were subsequently removed in a post-polymerization acid catalyzed hydrolysis. The effect of steric bulk and electronic factors on the resulting SFRP process was also investigated and revealed similar polymerization kinetics for various alkyl acrylates. However, addition of a hydroxyl containing monomer, 2-hydroxyethyl acrylate, resulted in an increase in the polymerization rate up to 2 times. The rate enhancement was attributed to hydrogen bonding effects and this was confirmed using the unprecedented addition of dodecanol, which also demonstrated a significant rate enhancement. Block copolymers were also achieved using a novel difunctional nitroxide synthesized from 4-hydroxy TEMPO and 1,6-hexamethylene diisocyanate. The identity of the nitroxide was confirmed using mass spectrometry and 1H NMR. The dinitroxide was used in the polymerization of styrene and subsequently used to produce symmetric ABA triblock copolymers with t-butyl styrene using a unique two-step polymerization route. In addition, the dinitroxide demonstrated an increased tendency for decomposition due to the complex mediation equilibrium. The decomposition was studied using GPC to evaluate the decomposition effects on the polymerization. Results of the research efforts presented herein are written as individual research reports with contributing authors and pertinent literature reviews presented at the beginning of each chapter. / Ph. D.

Diesel #2 is used to heat nearly 400,000 dwellings in Virginia. Home heating oil released from leaking underground tanks located adjacent to homes and residing in unsaturated soil adjacent to houses poses a potentially serious health risk. Specifically, the migration of hazardous vapors into buildings, known as vapor intrusion, can negatively impact indoor air quality in homes and public buildings (USEPA 2015). In this look-back study, we assessed the potential for petroleum vapor intrusion by sampling soil vapor at 25 previously remediated spill sites. Residual contaminants, in particular total petroleum hydrocarbons (TPH) and naphthalene, were detected in approximately 1/3 of the samples. Concentration levels were correlated to site variables (building type, remediation time, physiographic region) including previous abatement measures. Spill category as assigned by the remediation contractor was investigated in conjunction with these three site variables. Remediation time was the most promising predictive site variable, with visible trends downward in DEQ Category 2 sites with increased remediation time. Higher contaminant concentrations were found near basement-style dwellings, which we hypothesize is due to the wall of the basement blocking horizontal migration of contaminants and the flow of oxygen to the release source zone. We found that many sites exceeded the sub-slab risk target threshold in naphthalene concentration, which has negative implications on previous abatement strategy efficacy. / Master of Science

Thesis (MScEng (Process Engineering))--Stellenbosch University, 2008. / Please refer to full text to view abstract.

A exposição dos peixes a poluentes provoca danos nos organismos que podem ser identificados precocemente através de respostas biológicas. O presente estudo visou avaliar os efeitos do naftaleno e benzo(a)pireno em pampos da espécie Trachinotus carolinus. Foram avaliados os efeitos citogenotóxicos, histopatológicos e bioquímicos após exposições às concentrações de 0,9 M; 2,7 M e 8,1 M de NAP e BAP por períodos de 12, 24, 48 e 96 horas. O NAP causa quebra no DNA de eritrócitos de pampos em concentrações de 8,1 M e a partir de 12 horas de exposição. O BAP revelou ser genotóxico a partir da menor concentração e de 24 horas. A mutagenicidade de ambos os poluentes, avaliada através da indução de formação de micronúcleos e anormalidades nucleares eritrocitárias, também ocorre a partir de curtos períodos de exposição e freqüências de MN e ANE estão relacionadas com a duração da exposição. O período de exposição aos HPAs foi determinante na intensidade e severidade das lesões observadas nos tecidos dos peixes. A especificidade de CYP1A, observada segundo análise imunohistoquímica, ocorreu de maneira dose-dependente e evidenciada principalmente nos maiores períodos experimentais. Os poluentes orgânicos, nas condições experimentais utilizadas, não provocaram alteração significativa na atividade das enzimas catalase e GST da espécie. Os biomarcadores, citogenotóxicos e histopatológicos utilizados neste estudo, demonstraram ser ferramentas eficientes para aferir a toxicidade, genotoxicidade e mutagenicidade de NAP e BAP como também sua relação dose-resposta na espécie T. carolinus. / Effects of exposure of fish to pollutants can be identified through stress responses. The present study aims to evaluate the effects of naphthalene and benzo(a)pyrene in Florida pompanos, Trachinotus carolinus. Evidences from citogenotoxical, histopathological and biochemical studies showed that alterations caused by exposures to 0.9 M, 2.7 M and 8.1 M of NAP and BAP occurred within 12 to 96 hours. NAP at 8.1 M induced erythrocyte DNA strand breaks in pompanos since early periods of exposure. Genotoxic effects of BAP at the lowest concentration were documented soon after 24 hours of exposure. Mutagenotoxicity of both pollutants, as seen by the induction of MN and ENA, was revealed since early periods and their frequencies are related to the duration of exposure. Exposures to these PAHs, for longer periods, resulted in increased frequency and severity of lesions observed in fish tissues. Specificity of CYP1A, observed through immunohistochemical analyses, was related to the dose of the pollutants and mainly at longer periods of exposure. These organic pollutants, under the experimental conditions, did not interfere with the activity of liver catalase and GST of the species. The citogenotoxic and histopathologic biomarkers used in this study proved to be efficient tools to ascertain the toxicity, genotoxicity and mutagenesis of NAP and BAP, as well as their dose related response, in the species T. carolinus.