Download or read book Synthesis and Characterization of Electron Donor acceptor Subphthalocyanine Derivatives and Porphyrin Metal Complexes written by Lakshmi Chockalingam Kasi Viswanath and published by . This book was released on 2013 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multicomponent electron-donor acceptor systems incorporating supramolecules such as porphryins, phthalocyanines, subphthalocyanines, and perylenes have gained utmost importance in various fields of optoelectronics. Subphthalocyanines are unique, non-planar, aromatic supramolecules which have recently emerged as a platform for novel electron acceptors as they show great potential in photosynthetic systems. Subphthalocyanine is an excellent electron acceptor, when covalently linked to other electron donor species through the axial substitution and executes fast photoinduced electron transfer. The axial approach to a synthesis is advantageous in the sense that the electronic characteristics of the subphthalocyanine macrocyle are preserved. Subphthalocyanine derivatives prepared in this study are expected to have outstanding tunable properties for the development of artificial photosynthetic systems and various molecular electronic devices. This dissertation will center on the synthesis, characterization of various donor-acceptor conjugates of subphthalocyanine.
Download or read book From Porphyrins to Subphthalocyanines Characterization of Porphyrinoid Based Electron Donor Acceptor Conjugates written by Benedikt Platzer and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photophysical Characterization of a Series of Self assembled Donor acceptor Dyads Containing Porphyrin and N confused Porphyrin Electron Donors and Studies of the Tautomerization of N confused Porphyrins written by Jojo Joseph (Chemist) and published by . This book was released on 2013 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: Interactions such as pi-pi stacking in organic pi-systems, proton coupling, and hydrogen bonding can be utilized to prepare nanostructures with excellent mechanical and electronic properties. In particular, self-assembled donor-acceptor complexes have received much recent attention because of their potential applications in optoelectronics such as photovoltaic cells and organic light emitting diodes. Porphyrins and their derivatives have been extensively used as building blocks for nanomaterials because of their optical, electronic, catalytic and biochemical properties. The pi-pi stacking and metal coordination ability of porphyrins make them very suitable for the formation of self-assembled structures. The first part of this work involves the photophysical characterization of self-assembled donor-acceptor complexes, where porphyrin derivatives are used as electron donors together with electron acceptors such as naphthalene diimide, perylene diimide, or fullerenes. In the second part, the tautomerization of N-confused tetraphenylporphyrin in various solvents was probed using time-resolved fluorescence spectroscopy.The first part of the work described here is the photophysical characterization of a self-assembled chiral bolaamphiphiles comprised of central tetraphenylporphyrin (H2TPP) with naphthalenediimide (NDI)-lysine moieties flanked on both ends. The strong intermolecular pi-pi interactions between the H2TPP and NDI chromophores leads to the formation of monolayer rings which further stack to form self-assembled nanorods. The effect of local nanostructure of assemblies on the photophysical properties was probed using steady-state fluorescence, time-resolved fluorescence and femtosecond transient absorption spectroscopic studies. This work demonstrates the importance of controlling local nanostructure in modulating the photophysical properties of optoelectronic materials. The second project involves the photophysical characterization of self-assembled donor-acceptor complexes containing an H2TPP and NDI-lysine amphiphile. Strong intermolecular pi-pi interactions between the TPP and NDI chromophores, together with the proton transfer from the lysine head group to the porphyrin ring leads to self-assembly in chloroform. Photoinduced electron transfer in the nanorods was probed using steady state fluorescence, time-resolved fluorescence and femtosecond transient absorption spectroscopic studies. The third portion of this dissertation involves the photophysical characterization of donor-acceptor systems containing covalently bound porphyrin-fullerene dyads, where different numbers (1-4) of C60-fullerenes were attached to a porphyrin core to enhance electron transfer efficiency. In this work, the fluorescence quantum yield measurements, time-resolved fluorescence and femtosecond transient absorption spectroscopic studies were used to study electron-transfer from the porphyrin core to the fullerene group(s). The fourth project involved studies of the equilibrium of the two tautomers of N-confused tetraphenylporphyrins (NCTPP). The steady-state absorption and fluorescence spectra of NCTPP have been found to significantly depend on the nature of the solvent. The previously reported photophysical studies indicated that both NCTPP tautomers can coexist in certain solvents, presumably in equilibrium with one another, while other solvents exclusively prefer one tautomer or the other. In order to gain a better understanding of the NCTPP tautomerization, NCTPP was studied by time-resolved fluorescence spectroscopy in a series of solvents having different solvent parameters. Also examined in this work was the origin of a moderately strong excited state solvent isotope effect in both steady-state and dynamic measurements. In the final project, the spectroscopic properties of a novel self-assembled ZnNCTPP-PDI traid were examined. Donor-acceptor dyads using H2TPP have been examined for years, but studies of D-A dyads based on NCTPP have not been significantly explored. In this project a non-covalently linked D-A complex formed from a zinc N-confused tetraphenylporphyrin dimer [(ZnNCTPP)2] and a pyridyl substituted perylenediimide (Py-PDI-Py) were examined. The coordination of pyridyl group on the PDI with zinc results in the dissociation of the (ZnNCTPP)2 dimer and results in the formation of a ZnNCTPP-Py-PDI-Py-ZnNCTPP triad. Steady-state and time-resolved fluorescence measurements were performed to probe the formation of the triad as well as photoinduced electron transfer in this traid.
Download or read book Preparation and Characterization of Alkali Metal and Tin Porphyrin Compounds and the Synthesis and Reactivity of Tantalum V Porphyrin and Bis Benzamidinate Complexes written by Denisha Yolanda Dawson and published by . This book was released on 1998 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Pt II Complexes of Electron Donor and Acceptor Ligands written by Namrata Khanal and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Synthesis and Characterization of the Precursors and Metal Complexes of a Unique Non Charge Transfer Amino Substituted Porphyrin written by Paula Prayzner and published by . This book was released on 1994 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Synthesis of Subphthalocyanine Derivatives and the Immobilization of Porphyrin Complexes in Porous Organic Hosts written by Chris Zyskowski and published by . This book was released on 1999 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Long chained Porphyrin Derivatives and Their Cobalt Complexes written by Wootthiphan Jantayot and published by . This book was released on 2015 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis Characterization of New Amethyrin based Expanded Porphyrin Metal Complexes written by James Thomas Brewster (II) and published by . This book was released on 2017 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt: New expanded porphyrins are of interest in terms of understanding the electrochemical features of oligopyrroles and the determinants of aromaticity. They can also act as ligands to stabilize metal complexes whose structures can differ from those of the better-studied porphyrins and, separately, have been explored for use in photodynamic and radiation therapy, among other application areas. With these considerations in mind, Chapter 1 is designed to provide a brief introduction to expanded porphyrin chemistry. Chapter 2 serves to detail our work on an expanded porphyrin called dipyriamethyrin. The emphasis will be on its preparation and the synthesis of the uranyl complex. Chapter 3 furthers this discussion with the synthesis of a related system, naphtho-isoamethyrin, as well as its bis-copper and uranyl complex. All work not carried out by the author will be specified as to give credit to those who provided the much appreciated help and guidance. Furthermore, the author hopes to present the science in such a manner wherein both the novice and expert can appreciate and understand the beauty of the underlying science
Download or read book Preparation of Electron Donor and Acceptor Molecules for Porphyrin Derivatization written by Christoph Hoefler and published by . This book was released on 1992 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of a Porphyrin Dyad written by Dale A. Braden and published by . This book was released on 1995 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and characterization of porphyrin coumarin isonitrile metal complexes written by Armah M. Kpissay and published by . This book was released on 1995 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Photophysical Properties of Porphyrin containing Supramolecular Systems written by Rashid M. Altamimi and published by . This book was released on 2010 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: The self-assembly of organic molecules has attracted much interest because of the special properties and possible technological applications of the mesoscopic materials which are intermediate materials between molecules and solids.1 Structural and spectroscopic studies on J- and H-aggregates present valuable information for understanding interactions at the molecular level in aggregation processes, and may also provide understanding that leads to alternative molecular devices. The synthesis and preliminary photophysical properties of two generations (G1-G2) of glutamic acid-based peptide dendrimers containing free-base or zinc porphyrin at the cores were performed. In this work, steady-state absorption and fluorescence experiments for the free-base dendrimers 59 and 63 were observed to have similar spectra relative H2TPP in DMAc, while the absorption and fluorescence spectra of zinc porphyrin dendrimers 60 and 64 were almost identical to that of ZnTPP in DMAc. These dendrimers tend to not to aggregate in polar solvents like DMAc, therefore, other nonpolar solvents will be sought for self-assembly these dendrimers. Second, two electon donor (D)- acceptor (A) dyads are composed of free-base porphyrin (Fb) and perylene bisimide (PDI) groups that are linked by leucine (65) or polyleucine (n=2, the dyad 66) were prepared in this work. Fb and PDI were chosen because of the useful photophysical properties each exhibits that will enable us to perform both energy and electron transfer within each dyad. The absorption spectra of the dyads indicate a close match with the sum of the component spectra, indicating little or no electronic coupling occurs between porphyrin and PDI groups in the ground state. Due to the overlap of the emission bands of porphyrin and perylene, fluorescence quantum yield analysis could not be determined with any accuracy. Fluorescence excitation spectra will therefore be performed in the near future. Intramolecular FRET experiments will also be achieved on these two dyads, whereas these measurements will allow us to precisely determine the donor-acceptor distance at any given time. After we measure the distance between the donor-acceptor dyad, we will investigate how the rate of the electron transfer varies with the distance, and what effect the dyad structure has in controlling this rate constants. The photophysical and electrochemical properties of covalently-linked arrays of N-confused porphyrins (NCPs) are of interest to a variety of supramolecular and biomimicking materials. While differing from the parent porphyrins by inversion of only two atoms, NCPs exhibit physical and chemical properties different than normal porphyrins. The synthesis and preliminary photophysical properties of three dimeric and trimeric N-confused porphyrin (NCP) arrays (75, 77 and 80) are presented. The absorption and emission maxima for the NCP dimer (75) and trimers (77 and 80) in DMAc were found to be broader and red-shifted relative to that of NC-TPP. The fluorescence quantum yield [Phi]Fl calculated for these NCP arrays were found to be (~ 91-97%) smaller than the monomer NC-TPP. This fluorescence quenching can be attributed to energy-transfer between NCP units. Time-resolved fluorescence experiments will therefore be performed on these NCP arrays in the near future. Here, I also report the synthesis and preliminary characterization of a donor-acceptor triad containing zinc N-confused porphyrin dimer (ZnNCP) 87 and pyridine-appended PDI 95, to generate triad 89. The formation of triad 89 was monitored using UV-visible absorption and fluorescence spectroscopy upon titrating PDI 95 to the ZnNCP dimer 87 in CH2Cl2. The absorption intensity at 462 nm that is attribiuted to the free monomer ZnNCP reached a maximum with the addition of equal amounts of PDI 95 to ZnNCP 87. Further additions of PDI did not result in appreciable changes in the absorption intensity of the Soret and Q bands, confirming the complete dissociation of ZnNCP dimer and formation of the triad complex 88. The fluorescence intensity of ZnNCP monomer reached the maximum upon addition of one equivalent of the PDI 95. The intensity of ZnNCP emission was diminished with addition of access of PDI. The emission quenching with excess PDI addition can be attributed to formation of the penta-coordinate ZnNCP-PDI complex 88. This complex formation will further be investigated by means of time-resolved fluorescence spectroscopy as well as mass spectrometry.
Download or read book Supramolecular Photosensitive and Electroactive Materials written by Hari Singh Nalwa and published by Gulf Professional Publishing. This book was released on 2001-05-21 with total page 995 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the last decade, much progress has been made in these materials. This book presents a highly coherent coverage of supramolecular, photosensitive and electroactive materials, namely those that have been extensively investigated for applications in fields of electronic and photonic technologies. This extensive reference provides broad coverage of on different types of materials, their processing, spectroscopic characterization, physical properties and device applications.The implications reach from molecular recognition in synthetic and natural complexes to exciting new applications in chemical technologies, materials, nanostructures, functional materials, new generation catalysts, signal transducers, medical and biomedical applications and novel separation techniques. All these applications rely on supramolecular properties such as molecular recognition, molecular information, and tailored molecular assemblies.This book is aimed to present a highly coherent coverage of supramolecular, photosenstive and electroactive materials and their applications in electronic and photonic technologies. The research behind these materials constitute some of the most actively pursued fields of science. Key Features* Covers supramolecular photosensitive and electroactive materials* Provides recent developments on metallophthalocyanines and polydiacetylenes* Include various types of supramolecular materials, their processing, fabrication, physical properties and device applications* Role of polyimides in microelectronic and tribology* Describes Photosynthetic and respiratory proteins, Dendrimers* A very special topic presented in a timely manner and in a format
Download or read book Handbook of Porphyrin Science with Applications to Chemistry Physics Materials Science Engineering Biology and Medicine volume 5 written by Karl M. Kadish and published by World Scientific. This book was released on 2010 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first set of Handbook of Porphyrin Science.Porphyrins, phthalocyanines and their numerous analogues and derivatives are materials of tremendous importance in chemistry, materials science, physics, biology and medicine. They are the red color in blood (heme) and the green in leaves (chlorophyll); they are also excellent ligands that can coordinate with almost every metal in the Periodic Table. Grounded in natural systems, porphyrins are incredibly versatile and can be modified in many ways; each new modification yields derivatives demonstrated new chemistry, physics and biology, with a vast array of medicinal and technical applications.As porphyrins are currently employed as platforms for study of theoretical principles and applications in a wide variety of fields, the Handbook of Porphyrin Science represents a timely ongoing series dealing in detail with the synthesis, chemistry, physicochemical and medical properties and applications of polypyrrole macrocycles. Professors Karl Kadish, Kevin Smith and Roger Guilard are internationally recognized experts in the research field of porphyrins, each having his own separate area of expertise in the field. Between them, they have published over 1500 peer-reviewed papers and edited more than three dozen books on diverse topics of porphyrins and phthalocyanines. In assembling the new volumes of this unique Handbook, they have selected and attracted the very best scientists in each sub-discipline as contributing authors of the chaptersThis Handbook will prove to be a modern authoritative treatise on the subject as it is a collection of up-to-date works by world-renowned experts in the field. Complete with hundreds of figures, tables and structural formulas, and thousands of literature citations, all researchers and graduate students in this field will find the Handbook of Porphyrin Science an essential, major reference source for many years to come.
Download or read book Comprehensive Supramolecular Chemistry II written by George W. Gokel and published by Elsevier. This book was released on 2017-06-22 with total page 4627 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive Supramolecular Chemistry II, Second Edition, Nine Volume Set is a ‘one-stop shop’ that covers supramolecular chemistry, a field that originated from the work of researchers in organic, inorganic and physical chemistry, with some biological influence. The original edition was structured to reflect, in part, the origin of the field. However, in the past two decades, the field has changed a great deal as reflected in this new work that covers the general principles of supramolecular chemistry and molecular recognition, experimental and computational methods in supramolecular chemistry, supramolecular receptors, dynamic supramolecular chemistry, supramolecular engineering, crystallographic (engineered) assemblies, sensors, imaging agents, devices and the latest in nanotechnology. Each section begins with an introduction by an expert in the field, who offers an initial perspective on the development of the field. Each article begins with outlining basic concepts before moving on to more advanced material. Contains content that begins with the basics before moving on to more complex concepts, making it suitable for advanced undergraduates as well as academic researchers Focuses on application of the theory in practice, with particular focus on areas that have gained increasing importance in the 21st century, including nanomedicine, nanotechnology and medicinal chemistry Fully rewritten to make a completely up-to-date reference work that covers all the major advances that have taken place since the First Edition published in 1996
