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Book Design Synthesis and Application of Novel Conjugated Materials Part II

Download or read book Design Synthesis and Application of Novel Conjugated Materials Part II written by Haichang Zhang and published by Frontiers Media SA. This book was released on 2021-11-09 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Design and Synthesis of Donor Acceptor Conjugated Systems

Download or read book Design and Synthesis of Donor Acceptor Conjugated Systems written by Craig Yu and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Design and Synthesis of conjugated Polymers for Organic Optoelectronics

Download or read book Design and Synthesis of conjugated Polymers for Organic Optoelectronics written by 陳宏揚 and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Design and Synthesis of Organic Chromophores for Imaging Lithography and Organic Electronics

Download or read book Design and Synthesis of Organic Chromophores for Imaging Lithography and Organic Electronics written by Trisha Lionel Andrew and published by . This book was released on 2011 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: The absorption and emission maxima, photostabilities and photoreactivities of small-molecule organic chromophores can be tailored by (a) the choice of an appropriate parent structure and (b) the deliberate introduction of substituents that predictably alter the optical properties and photochemistry of this parent structure. Suitably-designed chromophores can be used in a variety of applications, such as imaging (for example, as fluorescent labeling agents or as indicators for specific analytes), optical lithography and as active components in organic electronic devices. In Chapter 1, a fluorogenic chemosensor to detect saturated nitramine and nitrate ester explosives was devised based on a photochemical reduction reaction. 10-Methyl-9,10- dihydroacridine (AcrH2) was found to transfer a hydride ion equivalent to the high explosives RDX and PETN upon irradiation at 313 nm in degassed acetonitrile solutions. Mechanistic photophysical studies indicated that the photoreduction of RDX proceeded via a two-step electron-hydrogen atom transfer reaction, whereas PETN photoreduction proceeded via a threestep electron-proton-electron transfer sequence. A zinc analog was synthesized and found to display an 80- or 25-fold increase in 480 nm emission intensity upon reaction with RDX or PETN, respectively; moreover, the Zn analog was found to be unresponsive to TNT and other common contaminants, in addition to being photostable under ambient conditions. In Chapter 2, the nitramine-containing explosive RDX and the nitroester-containing explosive PETN were shown to be susceptible to photodegradation upon exposure to sunlight. The products of this photodegradation were identified as reactive, electrophilic NOx species, such as nitrous and nitric acid, nitric oxide, and nitrogen dioxide. NN-Dimethylaniline was capable of being nitrated by the reactive, electrophilic NOx photodegradation products of RDX and PETN. A series of 9,9-disubstituted 9,10-dihydroacridines (DHAs) were synthesized from either N-phenylanthranilic acid methyl ester or a diphenylamine derivative and were similarly shown to be rapidly nitrated by the photodegradation products of RDX and PETN. An increase in the emission signal at 550 nm was observed upon nitration of DHAs due to the generation of fluorescent donor-acceptor chromophores. Using fluorescence spectroscopy, the presence of ca. 1.2 ng of RDX and 320 pg of PETN could be detected by DHA indicators in the solid state upon exposure to sunlight. In Chapter 3, optical lithography with organic photochromes is demonstrated. In the past, the formation of microscale patterns in the far field by light has been diffractively limited in resolution to roughly half the wavelength of the radiation used. We demonstrated lines with an -4- average width of 36 nm, about one-tenth the illuminating wavelength ( 11 = 325 nm), made by applying a film of thermally-stable photochromic molecules above the photoresist. Simultaneous irradiation of a second wavelength (k= 633 nm) rendered the film opaque to the writing beam except at nodal sites, which let through a spatially constrained segment of incident 1 light, allowing subdiffractional patterning. In Chapter 4, rylene dyes functionalized with varying numbers of phenyl trifluorovinylether (TFVE) moieties were subjected to a thermal emulsion polymerization to yield shape-persistent, water-soluble chromophore nanoparticles. Perylene and terrylene diimide derivatives containing either two or four phenyl TFVE functional groups were synthesized and subjected to thermal emulsion polymerization in tetraglyme. Dynamic light scattering measurements indicated that particles with sizes ranging from 70 - 100 nm were obtained in tetraglyme, depending on monomer concentration. The photophysical properties of individual monomers were preserved in the nanoemulsions and emission colors could be tuned between yellow, orange, red, and deep red. The nanoparticles retained their shape upon dissolution into water and the resulting water suspensions displayed moderate to high fluorescence quantum yield, thus making them attractive candidates for bioimaging applications. In Chapter 5, a series of substituted 6,6-dicyanofulvenes (DCFs) were synthesized starting from masked, dimeric or monomeric cyclopentadienones. DCFs lacking sufficient steric bulk around the fulvene core tended to reversibly undergo a [4+2] dimerization. In addition to being highly crystalline, DCFs were darkly-colored compounds due to the presence of weak electronic transitions in the visible region of the electromagnetic spectrum. DCFs displayed two distinct, reversible one-electron reductions by cyclic voltammetry. Based on their high crystallinity and suitable electron affinities, and buoyed by their relatively cheap and straightforward synthesis, DCFs are interesting candidates for organic electron-transport materials.

Book The Design and Synthesis of Extended Conjugated Systems

Download or read book The Design and Synthesis of Extended Conjugated Systems written by Shadi Rivadehi and published by . This book was released on 2012 with total page 546 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work contained within this thesis explores the synthetic strategies to several novel conjugated systems derived from porphyrin, NDI and TTF building blocks and their subsequent characterasation. These novel compounds have applicability in studying the factors that govern ET and EnT in interesting redox processes and as sensors. The bulk of research undertaken utilises the easy to prepare porphyrin-dione 44 and TTF 78 as well as tetrabromo NDI 19. Chapter 1 provides an introduction to the motivation for this research. The Chapter also summarises major directions in the fields of porphyrin, NDI and TTF chemistry and defines the significance and role of their properties as well as relevant applications.Chapter 2 explores the synthesis of novel porphyrinogens including oxidation of the porphyrin macrocycle. Core to the strategy is the porphyrin-dione 44. From this dione, porphyrin anhydride 57 and related metallo-porphyrins are synthesised and their physical properties explored. Obtaining porphyrin-lactone 58 as a side product during these reactions led us to synthesis novel lactams 62 and 63. Reaction of porphyrin-lactone 58 with hydrazine-hydrate converts the lactone moiety to an N-aminolactam 62. It also chemically reduces the antipodal pyrrolic moiety in the N-aminolactam, producing the chlorin-like N-aminochlorolactam 63 as well. This lactone-to-lactam replacement does not dramatically change the UV-visible spectroscopic properties of the N-aminolactam 62, however N-aminochlorolactam 63 shows intense Q band at 696 nm, which is larger than that of either of porphyrin-lactone 58 or N-amino-porpholactam 62, and is also shifted to the red region. Chapter 3 investigates the synthesis of novel porphyrin-TTF systems and their metal complexes. A tetrathiafulvalene donor has been annulated to 44 via quinoxaline linkers to form a novel asymmetric dyad 79. Chemical and physical properties are also outlined by utilising different methods such as UV-visible spectroscopy, fluorescence spectroscopy and cyclic voltammetry. These extended [pi]-conjugated molecules absorb light over a wide region of the UV-visible spectrum. Preliminary fluorescence testing of these compounds suggests that electron and/or energy transfer processes take place from the TTF unit as a donor to the porphyrin moiety as an acceptor. Also, cyclic voltametric studies allow the differentiate between the TTF and porphyrin sites with respect to the multiple redox processes occurring within these compounds. X-ray crystallography was used to characterise compound 79, adding to the structural information gained through other characterisation techniques.Chapter 4 investigates the synthesis of a new naphthalene diimide 104, in which a TTF donor has been attached to the naphthalene diimide core via a rigid bridge. The electronic properties of 104 are studied in detail. A strong electronic absorption profile extends far into the visible spectral region, which originates from its inherent electronic donor-acceptor nature. Also, the presence of a strong absorption at 1270 nm upon chemical oxidation, confirms significant [pi]-[pi] interactions in the compound due to aggregation.The work presented in Chapter 5 focused on synthesising of a novel 2,3-dipyrrol-2'-yl-TTF-quinoxaline 123, which is highly selective and sensitive for F- with detection possible by both colorimetric and fluorometric analyses. The target compound 123 was obtained via the direct condensation reaction of 78 with the 2,3-dipyrrol-2'-yl ethanedione 121 in good yield, and then characterized by various methods including X-ray crystallography. The UV-visible spectrum of 123 in DCM shows three strong absorption bands, which change after the addition of fluoride ion. Compound 123 also shows an emission intensity enhancement with slight red shift upon addition of F-, while no significant changes in the spectra of 123 was observed upon addition of AcO-, H2PO4-, Cl-, Br- and HSO4- in the same solvent. Chapter 6 reflects on the work undertaken in Chapters 2-5 and comments on future directions. It also describes some ancillary works to the main themes of this thesis. Synthesis of the NDI-TTF annulated compounds 126 and 127 under mild conditions are detailed, as well as dimer 128, which might have interesting photophysical properties. A new trimer 130 was also synthesised.

Book Organic Polymers

    Organic Polymers

    Book Details:
  • Author : Arpit Sand
  • Publisher : BoD – Books on Demand
  • Release : 2020-03-11
  • ISBN : 1789845734
  • Pages : 148 pages

Download or read book Organic Polymers written by Arpit Sand and published by BoD – Books on Demand. This book was released on 2020-03-11 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book, Organic Polymers, covers aspects that are of immediate concern to a new entrant to the field of polymers. Taken as a whole, these eight chapters aim to help the readers easily assimilate other specialized and exhaustive treatises on the subject. Topics dealing with the chemistry and technology of polymers are presented in a careful and logical manner so as to provide an easy and enjoyable read. Several examples and analogies are included so to make the main concepts easy to follow and tables and figures are included so that the book can serve, to a limited extent, as a hand book dealing with polysaccharides with different parameters. This book is meant for students studying polysaccharides and those working on graft copolymers and other allied polymer industries but without a formal educational background in organic polymers.

Book Rational Design and Synthesis of Sequence Defined Donor Acceptor Poly arylenevinylene s as Singlet Fission Materials

Download or read book Rational Design and Synthesis of Sequence Defined Donor Acceptor Poly arylenevinylene s as Singlet Fission Materials written by Stephen Koehler and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Donor-Acceptor poly(p-arylenevinylenes) (DA PAVs) are an untapped class of materials owing largely to their challenging synthesis. The Elacqua group recently reported the synthesis of such polymers by Ring-Opening Metathesis Polymerization (ROMP). The newly synthesized monomer polymerized with good control over molecular weight and was able to form block copolymers with poly(norbornene). In Chapter 2, the inherent steric and electronic bias of ROMP is leveraged within the same monomer scaffold to study how to monitor and influence polymer sequence. A combination of monomer steric bulk, reaction solvent, and temperature are all variables that can influence the sequence. While further study is needed, non-symmetric substitution of alkyl chains appears to be important in achieving controlled polymerizations. This comes with many limitations, namely a challenging monomer synthesis, for which we provide some perspective and insight to overcome this deficit. Given the remaining synthetic challenges, computational chemistry will be a particularly powerful tool to deliberately identify synthetic targets. Simulating polymer properties is a difficult task in itself; in Chapter 3, a high throughput screening method which is both more accurate and an order of magnitude faster than leading quantum mechanical methods was developed. Preliminary data supports a size-parameter relationship between monomers, which could be leveraged to further enhance the accuracy, and potentially used in simulating higher-dimensional conjugated structures like covalent organic frameworks. Circling back to screening-driven polymer design, Chapter 4 presents time-dependent density functional theory calculations that identify DA PAVs as a promising class of materials for singlet fission. This is due, in part to the planarization afforded by the vinyl-spacer. This is observed both when replicating reported methods, as well as when applying the high throughput screening capabilities developed in Chapter 3. Chapter 5 looks toward multifunctional devices or stimuli responsive organic electronics, wherein the synthesis of thiophene-appended spiropyran oligomers which can reversibly change their band gap energy are presented. The observed band gap energies agree well with DFT calculations, suggesting more diverse spiropyran-oligomers could be explored. However, fast isomerization with oligomer-appended spiropyran was not observed, though it is hypothesized that spirothiopyran could be an effective tool to overcome this. Overall, this work demonstrates progress in both synthetic and computational methodology to advance the development and discovery of organic electronic materials.

Book Molecular Design and Synthesis of a Donor acceptor Polymer

Download or read book Molecular Design and Synthesis of a Donor acceptor Polymer written by Nikolaj Klit and published by . This book was released on 2006 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book The Design and Synthesis of Organic Chromophores for Faraday Rotation and Photoluminescence

Download or read book The Design and Synthesis of Organic Chromophores for Faraday Rotation and Photoluminescence written by Zachary Nelson and published by . This book was released on 2021 with total page 229 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis summarizes the design, synthesis, and application of novel small-molecule and polymeric materials, with emphasis on understanding and tuning the chromophore electronic structure to maximize properties including Faraday rotation and delayed fluorescence. In Chapter 1, we introduce the magneto-optical property Faraday rotation. The current frontiers in performance, applications, and mechanistic understanding of Faraday rotation in organic-chromophore thin-films is discussed. Faraday rotation measurements of several novel materials are introduced in context. In Chapter 2, we evaluate the Faraday rotation in thin films of several phthalocyanine and porphyrin derivatives, and observe maximum Verdet constants greater than those found in competing inorganic materials. The effect of chemical modifications, including the introduction of paramagnetic and chiral centers, is discussed. In Chapter 3, we evaluate the Faraday rotation in thin films of pi-conjugated polymers when influenced by chiral moieties. We demonstrate the key role chirality serves in the magneto-optical properties of these materials, the influence of structural order and film thickness on Faraday rotation, and report among the largest Verdet constants observed to date in organic thin films. In Chapter 4, we develop the polymerization for and evaluate the properties of a new class of polyarylene chalcogenides. We utilized dynamic covalent SNAr behavior to demonstrate selective depolymerization. In addition, we studied the mechanism of the bright photoemission, ascribing it to delayed fluorescence enabled by the presence of sulfur atoms. In Chapter 5, we discuss the synthesis and properties of two classes of solution-processable materials: M(III) and Au(I) arylthiolate coordination polymers. We demonstrate the presence of strong metal-metal interactions between M(III) centers along the polymer backbone. Further, we discuss the strong phosphorescence and dynamic supramolecular coordination in the solution phase of the Au(I) coordination polymers.

Book Thiophene Based Conjugated Polymers for Optoelectronic Applications

Download or read book Thiophene Based Conjugated Polymers for Optoelectronic Applications written by Udaya Kumar Dalimba and published by LAP Lambert Academic Publishing. This book was released on 2012 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the last three decades, conjugated polymers have attracted much attention as active materials for optoelectronic applications, such as PLEDs, field-effect transistors, photovoltaic cells, optical switching devices, data storage devices etc. However, design and synthesis of -conjugated polymers with low oxidation potential, broad absorption spectrum, low band gap, efficient photoinduced charge transfer and separation, and ambipolar charge transport with high mobilities, effective -electron delocalization are crucial for the fabrication of the devices. In particular, tuning of the HOMO/LUMO energy levels of these polymers is of great importance for directing material properties towards the desired applications. A deeper understanding of structure-property relationship would help in designing new organic conjugated molecules by the judicious choice of functional substituents, and thus to tune their optical properties for applications in optoelectronic devices. In this context a series of donor-acceptor conjugated polymers are designed and are synthesized in this work. These polymers with good material properties are potential candidates for optoelectronic device applications."