Download or read book Synthesis and Photophysical Characterization of Porphyrin containing Supramolecular Systems written by Shana A. Garrison and published by . This book was released on 2005 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 Design Synthesis And Photophysical Properties Of Novel C60 Porphyrin Supramolecular Systems to 25 Pages 26 to 50 Pages 51 to 75 Pages 76 to 100 Pages 101 to 125 Pages 126 to 150 Pages 151 to 175 Pages 176 to 200 Pages 201 to 225 Pages 226 to 250 Pages 251 to 270 written by Ke Li and published by . This book was released on 2003 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photochemistry and Photophysical Characterization of Porphyrin N confused Porphyrin Dyads written by Elvin A. Alemán and published by . This book was released on 2006 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to understand and mimic the processes that occur in photosynthesis, the photophysical properties of a series of porphyrinic molecules have been investigated. This work is divided into five projects involving the study of three different porphyrins and porphyrinoids: 1) free base N-confused tetraphenylporphyrin and various substituted derivatives, 2) free base N-confused porphyrin-zinc porphyrin, N-confused porphyrinpyromellitimide and N-confused porphyrin-pyrene arrays, 3) free base tetraphenylcorroles, 4) a series of porphyrin-quinone arrays to probe porphyrin excited state structure and 5) a series of porphyrin-naphthalenediimide arrays to explore energy and electron transfer as a function of linker/bridge dendron type. N-Confused tetraphenylporphyrin (NCTPP) differs from tetraphenylporphyrin (H2TPP) by having one of the pyrrolic nitrogens inverted and facing outside the macrocycle, with a C-H group inside. The inverted pyrrole ring in NCTPP results in a change in the [pi]-system of the macrocycle, leading to photophysical properties that are different than those of H2TPP. The first project was intended to investigate the photophysical properties of the two NCTPP tautomers, as well as several substituted (di- and tetra-) NCTPP derivatives using several spectroscopic techniques, including steady-state absorption and emission spectroscopy, time-correlated single photon counting, femtosecond transient absorption and nanosecond transient absorption spectroscopy. The second project consisted of the studies the photophysical characterization of pentameric N-confused porphyrin-zinc tetraphenylporphyrin artificial light-harvesting array (NCP-ZnP4), the photophysical properties of an N-confused-pyromellitimide array (NCP-Pym4), and the photophysical characterization of an N-confused porphyrin-pyrene donor-acceptor dyad (NCP-Pyr). The supramolecular systems NCP-ZnP4, NCP-Pym4 and NCP-Pyr represent the first structures where an N-confused porphyrin has been covalently incorporated into an array designed to involve highly efficient photoinduced energy and electron transfer processes. Free base corroles differ from free base porphyrin by having one of meso methine carbons replaced by a direct pyrrole-pyrrole linkage. The fourth project in this dissertation involved the photophysical characterization of four free base triphenylcorroles using steady state absorption and emission spectroscopy, and time correlated single photon counting experiments. The photophysical results indicate that similar to NCTPP, there is noticeable solvent dependence on the corrole photophysical properties. It is postulated that these differences result from the presence of two (or more) different tautomers. Although regular tetraphenylporphyrins such as H2TPP and Zntetraphenylporphyrin (ZnTPP) have been extensively used in different artificial photosynthetic systems, their incorporation into arrays presents characterization challenges, and energy and electron transfer mechanisms differ from array to array. The fifth project presented here involved an investigation into the effects of donor-acceptor orientation on the electron transfer (ET) and charge recombination (CR) rate constants. In a series of porphyrin-benzoquinone (PBQ) dyads, methyl groups on the meso phenyl groups were used to control the orientation between the donor and acceptor groups. The rate constants for ET and CR in these compounds are discussed, as well as the ramifications of these results on porphyrin photophysics. The final project in this dissertation involved the study of the photophysical properties of a series of triads, where two ZnTPP electron donor groups were linked, using a flexible dendritic spacer, to a naphthalenediimide acceptor group. The flexibility in these triads permitted the formation of several conformers, which were investigated using steady state and time-resolved spectroscopic techniques as well as semi-empirical molecular orbital calculations.
Download or read book Handbook Of Porphyrin Science With Applications To Chemistry Physics Materials Science Engineering Biology And Medicine Volumes 1 5 written by Karl M Kadish and published by World Scientific. This book was released on 2010-03-16 with total page 2438 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 The Porphyrin Handbook written by Karl Kadish and published by Academic Press. This book was released on 2000 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Porphyrin Handbook, Volume 18: Multiporphyrins, Multiphthalocyanines and Arrays provides information pertinent to every aspect of the chemistry, synthesis, spectroscopy, and structure of phthalocyanines. This book examines the biology and medical implications of porphyrin systems. Organized into five chapters, this volume begins with an overview of the results obtained in the research concerning the properties and formation of a class of metal phthalocyanine derivatives containing of two macrocyclic units. This text then examines the luminescence and photophysical data of multiporphyrin systems in which the chromophore centers are held together by weak, medium, or strong bonding interactions. Other chapters consider the intensive electronic absorption and circular dichroism properties of chiral phthalocyanines. This book discusses as well the chemistry porphyrin and corrin systems. The final chapter deals with geoporphyrins or sedimentary porphyrins, which are the most abundant porphyrin derivatives on earth. This book is a valuable resource for research scientists, engineers, and clinicians.
Download or read book Handbook Of Carbon Nano Materials Volume 1 Synthesis And Supramolecular Systems Volume 2 Electron Transfer And Applications written by Karl M Kadish and published by World Scientific. This book was released on 2011-01-31 with total page 980 pages. Available in PDF, EPUB and Kindle. Book excerpt: A hands on reference guide for scientists working in the fields of chemistry, physics, materials science, polymer science, solid-state physics, devices, nanotechnology or supramolecular science of carbon nanomaterials. In-depth and comprehensive coverage of topics combined with the perspectives for future research by the contributing authors. An invaluable reference source essential for both beginning and advanced researchers in the field.
Download or read book Synthesis Of Porphyrin Containing Molecular Dyads For Radical Cation Generation written by Edgardo Manuel Hernandez-Alvarado and published by . This book was released on 2014 with total page 215 pages. Available in PDF, EPUB and Kindle. Book excerpt: The overall efficiency of photovoltaics is dictated by processes occurring within it. These processes include exciton formation, diffusion, dissociation and charge collection. This dissertation will focus around the fundamental issue of charge collection. In organic photovoltaics (OPVs) the rate of charge injection is dominated by the interaction between dissimilar materials, usually organic compound interacting with inorganic ones. In order to improve this rate of injection and, by direct consequence the efficiency of this process, fundamental knowledge of this organic-inorganic interface must be gained. In this work the focus will reside solely on creating molecules capable of probing the interface between the indium tin oxide (ITO) and the donor layer. At this interface, the usual charge transfer being transferred is the hole. Chapters 2 and 3 detail the synthesis and photophysical characterization of porphyrin-perylene diimide (Por-PDI) and porphyrin-fullerene (Por-C60) molecular dyads. The idea behind these moieties is that covalent attachment of these species to ITO should lead to a robust ohmic contact. Since these molecular dyads are capable of producing charge-separated states after photoexcitation, they should have the capacity to produce a radical-cation in close proximity to the ITO. This will translate to a capacity for probing the dynamics of the hole injection at this interface. Studies performed demonstrate that in fact these dyads are capable of producing a charge-separated state upon photo-excitation. The lifetimes of these states were determine to be 35 ps and 3 ns for the Por-PDI and Por-C60 respectively. Chapter 4 takes a different turn. It is focused on the application and extension of a solvent-free synthesis of metallated phthalocyanines (Pcs). Shown in chapter 4 is the synthesis of a series of metallated Pcs using various transition metals and group 3 elements. Photophysical and electrochemical investigation of these materials shows that they have near-infrared absorption and relative high HOMO levels making them potential candidates for OPV applications. In addition, they displayed non-linear optical behavior due to their highly polarizable pi-systems and the presence of axial susbtituents. Finally Chapter 5 describes the synthesis and characterization of porphyrin possessing rigid linkers. This chapter also shows the further directions in which the various ideas presented in this work could be driven.
Download or read book Functional Molecular Nanostructures written by Matthias Ballauff and published by Springer Science & Business Media. This book was released on 2005-02-14 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt: With contributions by numerous experts
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2007 with total page 1044 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Porphyrin Science written by and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume 1. Supramolecular chemistry -- Volume 2. Synthesis and coordination chemistry -- Volume 3. Synthetic methodology -- Volume 4. Phototherapy, radioimmunotherapy and imaging -- Volume 5. Heme proteins -- Volume 6. NMR and EPR techniques -- Volume 7. Physicochemical characterization -- Volume 8. Open-chain oligopyrrole systems -- Volume 9. Electronic absorption spectra - Phthalocyanines -- Volume 10. Catalysis and bio-inspired systems - Part I -- Volume 11. Catalysis and bio-inspired systems - Part II -- Volume 12. Applications -- Volume 13. Synthesis and structural studies -- Volume 14. Theoretical, electron transfer and physical studies -- Volume 15. Biochemistry of tetrapyrroles -- Volume 16. Synthetic developments - Part I -- Volume 17. Synthetic developments - Part II -- Volume 18. Applications and materials -- Volume 19. Biochemistry of tetrapyrroles - Part II -- Volume 20. Chlorophylls and related systems -- Volume 21. Catalysis -- Volume 22. Biophysical and physicochemical studies of tetrapyrroles -- Volume 23. Synthesis -- Volume 24. Coordination chemistry and materials -- Volume 25. Vitamin B12 and related systems -- Volume 26. Heme biochemistry -- Volume 27. Erythropoiesis, heme and applications to biomedicine -- Volume 28. Chlorophyll, photosynthesis and bio-inspired energy -- Volume 29. Porphyrias and sideroblastic anemias -- Volume 30. Heme proteins - Part II -- Volume 31. Synthesis - Part II -- Volume 32. Materials -- Volume 33. Applications - Part II -- Volume 34. Harnessing solar energy -- Volume 35. Cumulative index for volumes 1-34.
Download or read book Fundamentals of Porphyrin Chemistry written by Penelope J. Brothers and published by John Wiley & Sons. This book was released on 2022-06-20 with total page 887 pages. Available in PDF, EPUB and Kindle. Book excerpt: FUNDAMENTALS OF PORPHYRIN CHEMISTRY An indispensable and concise overview of the chemistry of porphyrins and related molecules In Fundamentals of Porphyrin Chemistry: A 21st Century Approach, a team of distinguished researchers delivers a compact and accessible introduction to the broad field of porphyrin chemistry. It discusses the basics of porphyrin synthesis and structure, as well as that of related molecules, and the current and future roles that porphyrins play in chemical transformations, materials design and synthesis, energy capture and transduction, human health, and the environment. This edited volume is a self-contained tutorial on concepts of critical importance to porphyrin chemistry and serves as the foundation for discussions about the applications of porphyrin-related compounds found in the second volume. This book contains: A thorough introduction to porphyrins, including their structure, nomenclature, naturally occurring porphyrins, synthetic porphyrins, and common families of porphyrin-related compounds Comprehensive explorations of chemical porphyrin synthesis, including how to synthesize porphyrins from simple, symmetric, and advanced ABCD-substituted porphyrins Practical discussions of the physical characteristics of porphyrins, including their structural features, electronic structure, spectroscopy, magnetism, electrochemistry, and electron transfer processes Perfect for experienced academic researchers in the field of porphyrin chemistry seeking a quick reference, Fundamentals of Porphyrin Chemistry: A 21st Century Approach is also an indispensable resource for researchers new to the field who need an overview directing them to literature in more focused areas.
Download or read book Expanded Contracted Isomeric Porphyrins written by J.L. Sessler and published by Elsevier. This book was released on 1997-08-21 with total page 533 pages. Available in PDF, EPUB and Kindle. Book excerpt: The porphyrins are a class of naturally-occurring macrocycles and are ubiquitous in our world. As such, they have been called the Pigments of Life. This auspicious designation reflects their importance in numerous biological functions. Indeed, life as we understand it relies on the full range of biological processes that are either performed by or catalyzed by porphyrin-containing proteins. Chlorophyll-containing photosynthetic reaction centers in plants, for instance, convert light energy into chemical energy while producing oxygen along the way. It is this oxygen, evolved from photosynthesis, that is transported, stored, and reduced by heme-containing proteins in many organisms, including mammals. Not surprisingly, therefore, these molecules remain of fundamental interest to chemists and biochemists. Indeed, they continue to be intensely investigated by researchers world-wide. Inspired by the importance of the porphyrins, a new research direction has emerged in recent years that is devoted to the preparation and study of non-porphyrin polypyrrole macrocycles. Here, the principal objectives have been to generate completely synthetic systems that bear some structural resemblance to naturally-occurring porphyrin derivatives while being quite different in their specific chemical makeup. Within this context, three different research directions have evolved, namely those involving the syntheses of contracted, isomeric, and expanded porphyrins, respectively. It is the chemistry of these systems that is the subject of this book. Because of the newness of the field, the emphasis of this book will be on synthesis and characterization (all work on porphyrin isomers and much of that associated with expanded porphyrins has only appeared in the last 10 years). One chapter on applications has, however, been included. Also, in the context of the preparative portions of the text, some efforts have been made to explain why various porphyrin analogue targets are of interest.
Download or read book Design Synthesis and Photophysical Properties of Novel C60porphyrin Supramolecular Systems written by Ke Li and published by . This book was released on 2004 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Porphyrin Science written by and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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, demonstrating 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. This 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 The Porphyrin Handbook written by Karl Kadish and published by Elsevier. This book was released on 2000 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Porphyrin Handbook, Volume 16: Phthalocyanines: Spectroscopic and Electrochemical Characterization provides information pertinent to every aspect of the chemistry, synthesis, spectroscopy, and structure of phthalocyanines. This book examines the biology and medical implications of porphyrin systems. Organized into five chapters, this volume begins with an overview of the photophysical properties of phthalocyanines that are important in relation to photosensitizers in photodynamic therapy, photoconductor, solar cells, and artificial photosynthesis. This text then describe how the data obtained from magnetic circular dichroism spectroscopy has provided the critical information required to describe the excited and ground state degeneracies of main group metallophthalocyanines complexes. Other chapters consider the electrocatalysis by electrodes modified with phthalocyanine sensors and complexes. This book discusses as well the properties of phthalocyanines and of their complexes. The final chapter deals with the experiments with organic pigment thin films. This book is a valuable resource for research scientists, engineers, and clinicians.
Download or read book Supramolecular Architectures Based on Porphyrin and Receptor Molecules written by Albertus Petrus Henricus Johannes Schenning and published by . This book was released on 1996 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:
