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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Greener dye synthesis: continuous, solvent-free synthesis of commodity perylene diimides by twin-screw extrusion

Cao, Q., Crawford, Deborah E., Shi, C., James, S.L. 27 January 2020 (has links)
Yes / A continuous, scalable, and solvent‐free method for the synthesis of various naphthalic imides and perylene diimides (PDIs) using twin‐screw extrusion (TSE) is reported. Using TSE, naphthalic imides were obtained quantitatively without the need for excess amine reactant or product purification. With good functional‐group tolerance, alkyl and benzyl amine derived PDIs (incl. commercial dyes) were obtained in 50–99 % yield. Use of K2CO3, enabled synthesis of more difficult aniline‐derived PDIs. Furthermore, an automated continuous TSE process for Pigments Black 31 and 32 is demonstrated, with a throughput rate of about 1500 g day−1, corresponding to a space time yield of about 30×103 kg m−3 day−1, which is 1–2 orders of magnitude greater than for solvent‐based batch methods. These methods provide substantial waste reductions and improved efficiency compared to conventional solvent‐based methods. / Engineering and Physical Sciences Research Council. Grant Numbers: EP/L019655/1, IAA1718-04-1117
2

Propriedades da N, N-DI (2-fosfonoetil) naftaleno diimida em solução e em filmes auto-montados à base de zircônio / Properties of N, N\'-DI (2-phosphonoethyl) naphthalene diimide in solution and in self-assembled zirconium-based films

Rodrigues, Magali Aparecida 14 July 2000 (has links)
Sintetizou-se uma nova diimida naftálica difosfônica, a N, N-bis(2-fosfonetil)naftaleno diimida (DPN), pela reação do dianidrido 1,4,5,5-naftálico com o ácido 2-aminoetil-fosfônico. Essa molécula foi caracterizada por H-RMN, micro-análise, titulação potenciométrica e análise de fosfato. Através de estudos fotofísicos e fotoquímicos do DPN em solução verificou-se que essas moléculas encontravam-se na forma monomérica em água e na forma de agregados em solventes orgânicos. Verificou-se que o rendimento quântico de fluorescência Φf dessa molécula é dependente do pH do meio, uma vez que ocorre diminuição do Φf com aumento do pH. Por estudos com fotólise de relâmpago e por experimentos de lente térmica resolvida no tempo, verificou-se que a diminuição do Φf com aumento do pH. Por estudos com fotólise de relâmpago e por experimentos de lente térmica resolvida no tempo, verificou-se que a diminuição Φf é causada principalmente por um aumento no cruzamento intersistema, de singleto a tripleto. Multicamadas à base de zircônio (Mallouk et al. 1987) do DPN foram obtidas substratos como vidro, silício e ouro. O crescimento de filmes em vidro foi acompanhado por espectroscopia de absorção e em filmes sobre o silício por elipsometria. Sobre a superfície de ouro, foram estudadas as propriedades de oxido-redução do filme por voltametria cíclica. Por estudos fotofisicos desses filmes depositados em vidro, verificou-se que os mesmos eram fotoativos, formando produtos fotoquímicos por processos radicalares. Por outro lado, quando se preparou micro-cristais, pricipitando-se o radical do DPN com o zircônio em solução, observou-se por espectroscopia de ressonância de spin eletrônico (EPR) que estas estruturas micro-cristalinas estabilizavam o radical do DPN em presença de ar por vários dias. / The new diimide N, N\' -bis-(2-phosphoethyl)-1,4,5,8-naphtalenediimide (DPN) was synthesized by reaction of 2-aminoethylphosphonic acid with the compound 1,4,5,8-naphatalene tetracarboxylic dianhydride. This molecule was characterized by 1H-RMN, elemental analysis, potentiometric titration and phosphorus analysis. By photophysical and photochemical studies of DPN in solution, it was verified that DPN is in monomeric form in aqueous solution and DPN is in an aggregated state in organic solvents. When the fluorescence spectra in aqueous media show a sharp decrease in the fluorescence quantum yield (Φf) with the increase in pH. By laser flash photolysis and thermal lensing, it was verified that this reduction of Φf with the increase pH can be attributed to an increment in the intersystem crossing processes when the pH increased. The zirconium phosphonate thin films formed from 1,4,5,8-naphtalene diimides were assembled on quartz, borosilicate glass (BK7), silicon or gold. The film growth was followed by absorption spectroscopy on quartz and BK7 and by ellipsometry on silicon substrate. Toe oxidation and reduction properties of the films were studied by cyclic voltammetry of films deposited on gold. Photophysical and photochemical data revealed that the films were photosensitive, giving rise to products derived by radicalar reactions. On the other hand, when the DPN radical was precipitated with Zr4+ in solution, micro-crystals were obtained which stabilized the radical in the presence of air for several days.
3

Estudo das propriedades eletrônicas e espectroscópicas de uma série de diimidas naftálicas com substituintes aromáticos com potencial aplicação em dispositivos de armazenamento e conversão de energia / Study of the electronic and spectroscopic properties of a series of naphthalic diimides with aromatic substituents with potential application to energy storage and conversion devices

Silva, Francisco de Araújo 30 May 2018 (has links)
As diimidas naftálicas simétricas têm sido vastamente estudadas devido suas propriedades químicas, ópticas, e eletrônicas. A possibilidade de modular suas propriedades com a substituição de grupos diversos na formação da imida, viabiliza aplicações em dispositivos eletrônicos, conversão de energia e produção de redes de coordenação metalo-orgânicas. Neste trabalho sintetizou-se uma série de 5 diimidas naftálicas (NDIs) simétricas com substituintes aromáticos. Foram analisadas as características espectroscópicas e eletrônicas com obtenção dos valores de band-gap óptico através de ensaios de voltametria cíclica e cálculos teóricos (DFT), mostrando a influência dos substituintes nas propriedades eletrônicas. Estas moléculas apresentam indícios de agregação em determinados solventes tornando possível a produção de filmes finos. As NDIs produzidas foram intercaladas em uma matriz inorgânica lamelar, o pentóxido de vanádio amorfo, e melhorando consideravelmente, via de regra, a capacidade específica de carga quando analisados em sistemas trocadores de íon lítio, aplicados geralmente em cátodos de bateria, com valores da ordem de 190 mA.h.g-1 (sob 100 uA, variação de E +1,2V à -1,2V). É provavelmente um dos primeiros trabalhos a utilizar NDIs em sistemas mistos de matrizes inorgânicas aplicados em trocadores de íons. Algumas apresentam potencial para dispositivos de conversão de luz em eletricidade. / Symmetric naphthalic diimides have been extensively studied due to their chemical, optical, and electronic properties. The possibility of modulating their properties by substitution with several groups in the formation of imides allows diverse applications in electronic devices, energy conversion, production of metallo-organic frameworks (MOFs). In this thesis, a series of 5 symmetrical aromatic-substituted naphthalic diimides (NDIs) were sinthesized. We have studied their optical and electronic characteristics obtaining optical band-gap with cyclic voltammetry tests and theoretical calculations (DFT), showing the influence of substituent in the electronic properties. Some of these imides may aggregate in certain solvents allowing this way the production thin films. The NDIs were intercalated in the inorganic intercalation matrix of amorphous vanadium pentoxide, and showed generally considerable improvement in the specific charge capacity when used in lithium ion exchange systems, that are usually applied in battery cathodes, reaching values of the order of 190 mA.h.g-1 (under 100 uA, E variation of + 1.2V to -1.2V). This is probably one of the first works using NDIs in mixed systems to applied inorganic matrices as ion exchangers. Some of them may be used for light conversion to electricity devices.
4

Estudo das propriedades eletrônicas e espectroscópicas de uma série de diimidas naftálicas com substituintes aromáticos com potencial aplicação em dispositivos de armazenamento e conversão de energia / Study of the electronic and spectroscopic properties of a series of naphthalic diimides with aromatic substituents with potential application to energy storage and conversion devices

Francisco de Araújo Silva 30 May 2018 (has links)
As diimidas naftálicas simétricas têm sido vastamente estudadas devido suas propriedades químicas, ópticas, e eletrônicas. A possibilidade de modular suas propriedades com a substituição de grupos diversos na formação da imida, viabiliza aplicações em dispositivos eletrônicos, conversão de energia e produção de redes de coordenação metalo-orgânicas. Neste trabalho sintetizou-se uma série de 5 diimidas naftálicas (NDIs) simétricas com substituintes aromáticos. Foram analisadas as características espectroscópicas e eletrônicas com obtenção dos valores de band-gap óptico através de ensaios de voltametria cíclica e cálculos teóricos (DFT), mostrando a influência dos substituintes nas propriedades eletrônicas. Estas moléculas apresentam indícios de agregação em determinados solventes tornando possível a produção de filmes finos. As NDIs produzidas foram intercaladas em uma matriz inorgânica lamelar, o pentóxido de vanádio amorfo, e melhorando consideravelmente, via de regra, a capacidade específica de carga quando analisados em sistemas trocadores de íon lítio, aplicados geralmente em cátodos de bateria, com valores da ordem de 190 mA.h.g-1 (sob 100 uA, variação de E +1,2V à -1,2V). É provavelmente um dos primeiros trabalhos a utilizar NDIs em sistemas mistos de matrizes inorgânicas aplicados em trocadores de íons. Algumas apresentam potencial para dispositivos de conversão de luz em eletricidade. / Symmetric naphthalic diimides have been extensively studied due to their chemical, optical, and electronic properties. The possibility of modulating their properties by substitution with several groups in the formation of imides allows diverse applications in electronic devices, energy conversion, production of metallo-organic frameworks (MOFs). In this thesis, a series of 5 symmetrical aromatic-substituted naphthalic diimides (NDIs) were sinthesized. We have studied their optical and electronic characteristics obtaining optical band-gap with cyclic voltammetry tests and theoretical calculations (DFT), showing the influence of substituent in the electronic properties. Some of these imides may aggregate in certain solvents allowing this way the production thin films. The NDIs were intercalated in the inorganic intercalation matrix of amorphous vanadium pentoxide, and showed generally considerable improvement in the specific charge capacity when used in lithium ion exchange systems, that are usually applied in battery cathodes, reaching values of the order of 190 mA.h.g-1 (under 100 uA, E variation of + 1.2V to -1.2V). This is probably one of the first works using NDIs in mixed systems to applied inorganic matrices as ion exchangers. Some of them may be used for light conversion to electricity devices.
5

A Photophysical Characterization on the Unique Properties of Perylene-3,4:9,10-bis((3,4,5(tris(oxtyloxy)benzohydrazide)-dicarboximide

Phillips, Sarah F. 05 October 2009 (has links)
No description available.
6

Polímeros de coordenação à base de cobalto(II) e N,N'-bis(4-piridil)-1,4,5,8-naftaleno diimida como ligante e suas propriedade estruturais, espectroscópicas e fotoelétricas / Coordination polymers based on cobalt(II) and N,N\'-bis(4-pyridyl)-1,4,5,8-naphthalene diimide as ligand and their structural, spectroscopic and electronic properties

Castaldelli, Evandro 05 February 2016 (has links)
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.
7

Polímeros de coordenação à base de cobalto(II) e N,N'-bis(4-piridil)-1,4,5,8-naftaleno diimida como ligante e suas propriedade estruturais, espectroscópicas e fotoelétricas / Coordination polymers based on cobalt(II) and N,N\'-bis(4-pyridyl)-1,4,5,8-naphthalene diimide as ligand and their structural, spectroscopic and electronic properties

Evandro Castaldelli 05 February 2016 (has links)
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.
8

Rational Design Facile Synthesis of Boryl Anilines : Intriguing Aggregation Induced Emission and External Stimuli Responsive Properties

Sudhakar, Pagidi January 2015 (has links) (PDF)
The main thrust of this thesis is the development of facile synthetic routes for simple boryl anilines and study their structure-property correlations in both solid and solution states and to utilize this information to design functional materials with desired properties such as aggregation induced emission, mechanofluorochromism, and thiol sensors. This thesis contains eight chapters and the contents of each chapter are described below. Chapter 1 The first chapter is an introduction to the theme of the thesis and presents a general review on the present work with emphasis on photophysics of triarylboron based donor-acceptor systems and their applications in various fields. In addition, advances in boron chemistry in the new frontier areas such as aggregation induced emission and mechanochromism are discussed in brief. Chapter 2 The second chapter deals with the general experimental techniques and synthetic procedures utilized in this work. Chapter 3 This chapter describes the rational design and synthesis of triarylborane bearing Unsubstituted amines, namely borylanilines (3.1-3.5). Compounds 3.1-3.4have similar donor and acceptor centres but differ their molecular conformations and also differ in the relative positions of amine moiety (para and meta). Compounds 3.1-3.4 contain one amine group while 3.5 contains two amine moieties. These compounds exhibit fascinating electrostatic intermolecular interactions, N −H- - -π in the crystal structure of 3.1, 3.2 and 3.4 and N −H--N interactions in crystal structure of 3.5. The solution state optical properties of 3.1-3.5 are typical of donor-acceptor (D-A) systems. Interestingly, compounds 3.3 and 3.5 showed unprecedented mechanochromic luminescent properties. Upon grinding, compound 3.3 showed color changes from blue to cyan blue and 3.5 showed intriguing color changes from blue to green and these color changes were found to be reversible. Single crystal X-ray diffraction analysis of 3.5BP (blue emission color crystal) and 3.5GP (green emission color crystal) clearly show that the color changes are due to the difference in their solid state packing. Chapter 4 In chapter 4, the design and facile synthesis of boron based donor-acceptor (D-A) systems such as borylanilines 4.4-4.9 (D= -NH2 for 4.4-4.6 and -NMe2 for compounds 4.7-4.9) are reported. Compounds 4.4, 4.5 and 4.6 contain one, two or three -NH2 moiety(ies), respectively. Compounds 4.7, 4.8 and 4.9 contain one, two or three –NMe2 moiety(ies), respectively. A systematic investigation has been carried out to rationalize the effect of donor-acceptor ratio on the ICT process in borylanilines 4.4-4.9. The aryl spacer between donor amine and acceptor boron is kept the same in all the compounds to avoid the electronic effect of spacer on the ICT characteristics of these compounds. In the case of compounds 4.4-4.6, the increase in the number of donor -NH2 moieties does not affect their absorption profile, while in the case of compounds 4.7-4.9, the absorption spectra are shifted bathochromically with an increase in the number of donor-NMe2 moieties. Photoluminescence (PL) of 4.4-4.6 is significantly blue shifted with an increase in number of –NH2 moieties, while the PL of 4.7-4.9 was slightly blue shifted. The absorption and PL features of 4.4-4.6 are sensitive to the polarity of the solvent medium. In contrast, absorption profiles of 4.7-4.9 are not sensitive to the polarity of the solvent medium. The PL of these compounds is affected by the polarity of the solvent medium. Chapter 5 This chapter deals with triarylboron based fluorescent probes (5.1-5.4) for the selective detection of thiophenols over aliphatic thiols. The probes were constructed by conjugating luminescent borylanilinies with luminescent quencher 2,4-dinitrobenzene sulfonyl (DNBS) moiety. In compound 5.1 and 5.2 the DNBS moiety is positioned at the para position with respect to the triarylborane moiety, while in 5.3 and 5.4 the DNBS moiety(ies) is(are) at the meta position(s). Probes 5.1-5.4 showed selective turn-on fluorescence response towards thiophenol. The fluorescence “off-on” switching mechanism of 5.1-5.4 against thiophenols was fully elucidated by theoretical calculations. Probes 5.1-5.4 are also capable of detecting thiophenols in the intra cellular environments. Chapter 6 Design, facile synthesis and aggregation induced emission properties of a new series of novel triarylboron tethered N-aryl-1,8-naphthalimides (TAB-NPIs) 6.1-6.7 are described in this chapter. Systematic structural perturbation has been used for fine-tuning the optical and morphological properties of TAB- NPIs in both solid as well as in aggregated state. Compounds 6.1-6.7 are weekly luminescent in solutions. In contrast, all compounds (except compound 6.4) are strongly luminescent in the solid state and aggregated state in THF-H2O mixtures. The presence of sterically hindered boryl unit in 6.1-6.7 has endowed these molecules with unique AIE characteristics by preventing co-facial arrangements of NPI moieties. The propeller shape arrangement of TAB moiety in 6.1, 6.2, 6.5, 6.6 and 6.7 effectively prevents the aggregation induced emission quenching (AIEQ) and induce strong emission in the condensed state. In the solid state, compounds 6.1, 6.4, 6.5, and 6.6 generate an interesting supramolecular structure via intermolecular C-H--- and C-H---O interactions. No face to face intermolecular π---π interactions were found in the crystal structures of 6.1, 6.4, 6.5, and 6.6. This precludes the excimer formation which can be detrimental to the radiative process in these molecules. The scanning electron microscopy (SEM) images of as prepared samples of 6.1-6.7 clearly indicate that the morphology of these compounds strongly depends on the molecular conformations and number of naphthalimide moieties in the TAB-NPI conjugates. Chapter 7 This chapter deals with design, synthesis and optical properties of novel dimesitylboryl appended perylenediimides. A simple synthetic strategy has been developed for the construction of novel TAB-PDIs conjugates. These conjugates can be conveniently synthesised by condensation of boryl anilines with perylene tetracarboxylic acid anhydride. The incorporation of TAB moiety enhanced the solubility of perylen bisimides in common organic solvents. The PL quantum yield of both 7.1 and 7.2 strongly depends on the excitation wavelength. Lower Pl efficiency observed for 7.1 and 7.2 upon excitation in the boryl dominated absorption region may be due to the photon induced electron transfer form mesityl units of boryl to perylene bisimide moiety. The morphology as well as emission colours of supramolecular architectures of both 7.1 and 7.2 can be modulated by controlling the concentrations of DCM solutions of these compounds. Both the compounds showed selective fluorogenic response for F-1 and CN-1 anions. The simple synthetic strategy reported in this chapter can be conveniently exploited for the construction of TAB conjugates of semiconducting organic anhydrides. Chapter 8 Novel planar chiral Lewis acids 8.3(SP, SS), 1-phosphino-2-borylferrocenes 8.4(SP) and 2-phosphino-1-borylferrocenes 8.4(RP) have been synthesized from a readily accessible ferrocene sulphinate precursor. Adopting a simple synthetic approach and a single precursor, enantiomerically pure SP and RP isomers have been prepared. It would be worthwhile to investigate the catalytic properties of compounds 8.3(SS), 8.4(SP) and 8.4(RP). It would also be interesting to replace the mesityl groups on boron with other electron deficient groups like pentafluorophenyl and 1,3,5-trifluoromethylphenyl to fine tune the Lewis acidity of boron center and to set-up a general route to enantiomerically pure Planar Chiral Frustrated Lewis Pairs (PCFLP’s).
9

Investigation into water-soluble perylene diimides for thin film formation

Weitzel, Corey R. January 1900 (has links)
Master of Science / Department of Chemistry / Daniel A. Higgins / Three water-soluble perylene diimides (PDIs) were investigated to examine differences in their thin film forming properties. The PDI thin films investigated in this thesis are formed in an electrostatic-self-assembled (ESA) layer-by-layer (LBL) process by the use of a dip coater. The three PDIs employed are sodium bis (sulfonatopropyl) perylene diimide (PDISO[subscript]3[superscript]2-), bis (trimethylammonioethyl) perylene diimide diiodide (PDIDI[superscript]2+), and N-(butoxypropyl)-N'-(2-(N,N,N-trimethylammonio)-ethyl) perylene-3,4,9,10-tetracarboxylic diimide iodide (C[subscript]7OPDI[superscript]+). Thin films were made by alternately depositing the PDIs with counter polyelectrolyte (PEs). The PEs employed were poly(diallyldimethylammonium chloride) (PDDA[superscript]+) and poly(acrylic acid) (PA[superscript]-), depending on the charge of the PDI. PDIs were determined to be aggregated in all three PDI precursor solutions. The fraction of PDI aggregated in each was found to be 0.972, 0.903, and 0.993, for the PDISO[subscript]3[superscript]2-, PDIDI[superscript]2+, and C[subscript]7OPDI[superscript]+, respectively. The C[superscript]7OPDI[superscript]+ solution was the most aggregated only having one charge group, which makes it more hydrophobic. Thin films prepared from the solutions all displayed an absorbance spectrum similar to the aggregated form. All the composites displayed linear growth in film thickness and fiber width with bilayer number. However, the three composites gave unique surface morphologies. The PDISO[subscript]3[supercript]2-[dot in middle of line]PDDA+ composite was found to incorporate highly curled intertwined fibers compared to the PDIDI[superscript]2+[dot in middle of line]PA[superscript]- composite, where the fibers were not intertwined. The fiber structure was found to change after 15 bilayers. This change in morphology was attributed to the fibers grafting together and overlapping causing the loss of original fiber structure. The two symmetric composites differed in the film thickness with the PDISO[subscript]3[superscript]2-[dot in middle of line]PDDA[superscript]+ being thicker than the PDIDI[superscript]2+[dot in middle of line]PA[superscript]- composite. This was attributed to the molecular weights (MW) of the polyelectrolytes investigated during thin film deposition, with the PDDA[superscript]+ having a much higher MW. C[subscript]7OPDI[superscript]+[dot in middle of line]PA[superscript]- thin film composite had a film thickness approximately equal to the PDISO[subscript]3[superscript]2-[dot in middle of line]PDDA[superscript]+ composite, indicating precursor aggregation also influences deposition rate. The C[subscript]7OPDI[superscript]+[dot in middle of line]PA[superscript]- composite incorporated wavy thin fibers that appeared aligned in the dipping direction. This alignment was visible for bulk samples in UV-vis absorption dichroism studies. The alignment was parallel to the dipping direction of the substrate.
10

METAL COMPLEXES OF SCORPIONATE-LIKE POLYIMIDO SULPHUR PHOSPHANYL LIGANDS / Metallkomplexe Skorpionat-ähnlicher Polyimido-Schwefel-Phosphanyl Liganden

Meinholz, Margret 11 May 2011 (has links)
No description available.

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