Thesis (Ph.D.)--University of Tulsa, 1992. / Bibliography: leaves 109-113.

Thesis (Ph. D.)--Northeastern University, 2007. / Graduate School of Arts and Sciences, Dept. of Chemistry and Chemical Biology. Includes bibliographical references.

Thesis (M.S.)--University of Toledo, 2008. / Typescript. "Submitted as partial fulfillment of the requirements for the Master of Science Degree in Chemistry." "A thesis entitled"--at head of title. Bibliography: leaves 58-62.

Thesis (Ph. D.)--University of Hong Kong, 1998. / Includes bibliographical references (leaves 220-234).

Thesis (Ph. D.)--University of Hong Kong, 1999. / Includes bibliographical references.

Thesis (M.Sc.) -- Memorial University of Newfoundland. / Typescript. Bibliography : leaves 48-51. Also available online.

Thesis (Ph. D.)--Virginia Commonwealth University, 2006. / Prepared for: Dept. of Chemistry. Bibliography: leaves 95-102. Also available online.

The class of compounds known as the dibenzotetraaza[14]annulenes have been of particular interest over the past 25 years, with the initial impetus for research being the relationship they hold with the naturally occuring porphyrins. The main aim of the work undertaken was to establish the potential of dibenzotetraaza[14]annulene type systems for the development of novel materials whose applicable behaviour was likely to fall into one of the following three categories; liquid crystals, organic conductors, and chelating systems. Additionally the chemistry involved with the synthesis of these types of materials was interesting in its own right and provided a platform for the author to increase his own knowledge of chemistry. The research undertaken may be broadly classified into the following areas: 1. The preparation of linear Schiff base polymers, 2. The preparation of dibenzotetraaza[14]annulenes (metal complexes and free ligands), 3. The preparation of 1-D and 2-D unsymmetrical macrocyclic complexes, and 4. The preparation of polymeric materials incorporating dibenzotetraaza[14]annulenes both as part of the polymeric backbone and as pendant side chains in a comb type polymer. 1. The preparation of linear Schiff base polymers. The Schiff base condensation of phenylenediamines with malondialdehydes has enabled the preparation of materials of the type illustrated below. [chemical formula]. Examination of the materials by differential scanning calorimetry has shown that many of the materials exhibit interesting thermal transitions from one crystalline state to another. However the use of thermal microscopy has not shown any of these phases to be liquid crystalline transitions. 2. The preparation of dibenzotetraaza[14]annulenes (metal complexes and free ligands). An extensive array of dibenzotetraaza[14]annulenes have been prepared, generally by a one step process involving the reaction of ortho-phenylenediamine and various 2-substituted malondialdehydes in the presence of a suitable acid catalyst and solvent. [chemical formula]. 3. The preparation of 1-D and 2-D unsymmetrical macrocyclic complexes. The introduction of unsymmetricality into the dibenzotetraaza[14]annulenes has been of interest since dipole-dipole interactions between molecules may lead to enhanced crystalline stacking, which in turn has a direct effect on any liquid crystalline or semiconducting properties the material may exhibit. Consequently the preparation of unsymmetrical dibenzotetraaza[14]annulenes has been undertaken, which has often required extended stepwise synthetic reaction pathways involving the use of protecting reagents. Small quantities of pure materials have been prepared and are believed to be the first of their type. 4. The preparation of polymeric dibenzotetraaza[14]annulenes. The incorporation of dibenzotetraaza[14]annulenes into a polymeric system has been examined in two ways. The initial study concentrated on the incorporation of the macrocycle directly into the polymer backbone and involved the reaction of suitably functionalised dibenzotetraaza[14]annulenes with linking groups such as para-phenylenediamine. The additional study has focussed on a method of forming polymers which include the macrocyclic complexes as pendant side chains in a comb type polymeric arrangement (illustrated below). [chemical formula]. At present the prepartion of a polymer of this type has not been achieved. However an extensive study into the attachment of groups to the macrocycles which are capable of undergoing polymerisation has been undertaken which has established the potential use of the Gabriel synthesis of amines and the Wittig reaction as potential methods of attachment.

Organic donor and acceptor have promised the better future energy technologies to alleviate global energy demand and environmental issues. And nowadays they begin to come true in bulk heterojunction organic solar cells (BHJ OSCs) with advantages of low-cost, light-weight, large-area, flexibility, and with high efficiencies (PCEs) of over 14% for converting solar energy to electricity. Porphyrins are unique potential for artificial photocatalysis but their application in BHJ OSCs are still limited by the PCEs less than 10%. This complicacy comes from their inadequate spectral absorptions and the imperfect morphologies. In this thesis, we devote to chemical modification of acceptor-π-porphyrin-π-acceptor (A-π-Por-π-A) structural molecules to enhance their spectral absorptions and phase-separation functions with fullerene acceptor. Firstly, chemically driving J-aggregates have been studied on the new A-π-Por-π-A porphyrin molecule, which could improve the phase-separation of its blend film with PC71BM and and enhance its performance in BHJ OSCs with PCE up to 8.04%. Secondly, two new benzodithiophene (BDT) π-bridged A-π-Por-π-A molecules have been prepared with complementary absorption between the Soret and Q bands. The devices based on the blend fims of the porphyrin donor and PC71BM acceptor exhibit full spectral photocurrent generation and impressive PCEs up to 7.92%. Thirdly, we further extended the π-conjugation of the above BDT π-brigded A-π-Por-π-A molecules by inserting alkyl chain substituted thiophene derivatives into their backbones, resulting in new porphyrin molecules with UV-visible-near-infraed absorption spectra. Using those porphyrin molecules as donor and PCBM as acceptor, the devices show full spectra photocurrent generatoion and appropriate film morphology, resulting in high PCE up to 8.59%. Besides, photocatalysis is also a new promising technology to generate renewable energy. We herein develop new low-cost and noble-metal-free photocatalysts based on Co(OH)2 modified CdS nanowires and applied them for visible light driven hydrogen production from water-splitting. The optimum H2 production rate reaches 14.43 mmol·h−1·g−1 under (λ ≥ 420 nm) upon visible light irradiation, which is 206 and 3 times larger than that of the pristine CdS NWs and 1 wt% Pt-CdS NWs, respectively. The results indicate the promising application of earth-abundant Co(OH)2 as alternative cocatalysts of noble metals.

Orientador: Renato Atílio Jorge / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-17T02:06:37Z (GMT). No. of bitstreams: 1 Alves_JulianaMachadodaSilveira_M.pdf: 2543897 bytes, checksum: cfe682f5663f70da68e8234395efa7bc (MD5) Previous issue date: 2010 / Resumo: As porfirinas 5,10,15,20(3-hidroxifenil)porfirina (m-THPP), 5-hexil-10,20-bis(3hidrofenil)porfirina (hex-m-bisHPP) e 5-hexil-10,15,20-tris(3-hidroxifenil)porfirina (hex-m-triHPP), têm o mesmo rendimento quântico de oxigênio singleto e foram encapsuladas em nanopartículas (NPs) poli(láctico-co-glicólico) (PLGA) 50:50, preparadas através do método de emulsão e evaporação. As NPs obtidas têm diâmetros médios na faixa de submicrometros (<240 nm) e pequena dispersividade. O potencial zeta medido mostrou uma pequena variação (de -21.6 mV a -19.3 mV). A porcentagem de encapsulação das porfirinas obtidas foram: 93 ± 2; 97 ± 2 and 69 ± 1 para m-THPP, hex-m-bisHPP e hex-m-triHPP respectivamente. A eficácia fotodinâmica e a internalização das porfirinas foi investigada a 37oC utilizando células humanas cancerígenas de próstata (LNCaP). Após 2 horas de incubação com as NPs contendo a porfirina as porcentagens de internalização celular foram iguais para todas as porfirinas. As três porfirinas causam morte celular e dão a mesma viabilidade quando se varia o tempo de incubação (30-120 min), concentração da porfirina (2,5 a 7,5 mmol L) e dose de luz incidente (33 a 99 J cm). Análise das células por microscopia confocal mostrou que as porfirinas encapsuladas nas NPs foram localizadas no citoplasma, sempre na região perinuclear. Estes resultados mostram que porfirinas com estruturas semelhantes e anfifilicidades diferentes, com igual rendimento quântico de rendimento singleto e internalizadas nas células em concentrações iguais, tem a mesma eficácia fotodinâmica / Abstract: Porphyrins (5,10,15,20-tetra(3-hydroxyphenyl)porphyrin (m-THPP), 5-hexyl-10,20-bis(3-hydroxyphenyl) porphyrin (hex-m-bisHPP) and 5-hexyl-10,15,20-tris(3-hydroxyphenyl)porphyrin (hex-m-triHPP)) with different amphiphicities and equal singlet oxygen quantum yield in ethanol, were encapsulated into 50:50 poly(lactide-co-glycolide,) (PLGA) nanoparticles (NPs) prepared by the emulsion/evaporation technique. The NPs obtained had submicron average diameters (<240 nm) with low polydispersity. The zeta potential measurements showed slight variations in negativity (from -21.6 mV to -19.3 mV). Particle recovery (%) was determined with results of 93 ± 2; 97 ± 2 and 69 ± 1 for m-THPP, hex-m-bisHPP and hex-m-triHPP porphiryns, respectively. The photodynamic efficacy of the porphyrin-loaded nanoparticles and their cellular uptake at 37 oC was investigated with LNCaP prostate tumour cells. After 2 h incubation with porphyrin-loaded nanoparticles the percents of intracellular uptake were the same for all porphyrins. The three porphyrins cause cell death and gave the same cell viability with variations of incubation time (30¿120 min), drug concentration (2.5 to 7.5 mmol L) and incident light dose (33 to 99 J cm). Confocal laser scanning microscopy data showed that the porphyrin-loaded nanoparticles, were localized in the cells, always in the perinuclear region. These results show that porphyrins with similar structures and equal singlet oxygen quantum yields and internalized in equal concentrations in the cells, but different amphiphilicities, have equal photodynamic efficacy / Mestrado / Físico-Química / Mestre em Química