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Assembling Artificial Photosynthetic Models in Water Using β-Cyclodextrin-Conjugated Phthalocyanines as Building Blocks

Description: Article describes how two water-soluble zinc(II) phthalocyanines substituted with two or four permethylated β-cyclodextrin (β-CD) moieties at the α positions have been utilized as building blocks for the construction of artificial photosynthetic models in water. The hydrophilic and bulky β-CD moieties not only can increase the water solubility of the phthalocyanine core and prevent its stacking in water but can also bind with a tetrasulfonated zinc(II) porphyrin (ZnTPPS) and/or sodium 2-anthraq… more
Date: March 29, 2023
Creator: Chen, Xiao-Fei; Gobeze, Habtom B.; D'Souza, Francis & Ng, Dennis K. P.
Item Type: Refine your search to only Article
Partner: UNT College of Science
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Redox Reactions of Metalloporphyrins and their Role in Catalyzed Reduction of Carbon Dioxide

Description: Pulse radiolysis and laser photolysis are used to study redox processes of metalloporphyrins and related complexes in order to evaluate these light absorbing molecules as sensitizers and intermediates in solar energy conversion schemes. The main thrust of the current studies is to investigate the role of reduced metalloporphyrins as intermediates in the catalyzed reduction of carbon dioxide. Studies involve cobalt and iron porphyrins, phthalocyanines, corroles, and corrins as homogeneous cataly… more
Date: September 1, 2002
Creator: Neta, P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Donor-Acceptor Artificial Photosynthetic Systems: Ultrafast Energy and Electron Transfer

Description: Mother nature has laid out a beautiful blueprint to capture sunlight and convert to usable form of energy. Inspired by nature, donor-acceptor systems are predominantly studied for their light harvesting applications. This dissertation explores new donor-acceptor systems by studying their photochemical properties useful in building artificial photosynthetic systems. The systems studied are divided into phthalocyanine-porphyrin-fullerene-based, perylenediimide-based, and aluminum porphyrin-based … more
Date: December 2021
Creator: Seetharaman, Sairaman
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Formation and Photoinduced Electron Transfer in Porphyrin- and Phthalocyanine-Bearing N-Doped Graphene Hybrids Synthesized by Click Chemistry

Description: Article presents research where N-doped graphene (NG) has been covalently decorated with porphyrin and phthalocyanine moieties using click chemistry. Evidence of charge separation in these hybrids is secured from femtosecond transient absorption studies, acting NG as electron acceptor.
Date: March 7, 2022
Creator: Arellano, Luis M.; Gobeze, Habtom B.; Barrejón, Myriam; Parejo, Concepción; Álvarez, Julio C.; Gómez-Escalonilla, María J. et al.
Item Type: Refine your search to only Article
Partner: University of North Texas
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Multilayer self-assemblies as electronic and optical materials

Description: The layer-by-layer growth of film structures consisting of sequential depositions of oppositely charged polymers and macrocycles (ring-shaped molecules) have been constructed using molecular self-assembly techniques. These self-assembled thin films were characterized with X-ray reflectometry, which yielded (1) the average electron density, (2) the average thicknesses, and (3) the roughness of the growth surface of the self-assembled multilayer of macrocycles and polymers. These observations sug… more
Date: December 31, 1997
Creator: Li, DeQuan; Luett, M.; Shi, Xiaobo & Fitzsimmons, M. R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Structure-function relationships of second hyperpolarizabilities in two-dimensional molecules

Description: The enhancement of the third order susceptibilities X{sup (3)} and second order molecular hyperpolarizabilities <{gamma}> in a series of covalently stacked dimer and trimer macrocycles (SiPc and SiNc) was observed through the phase conjugated signals from DFWM measurements at both 1064 and 532 nm. The FWHM of the phase conjugated signals at 532 nm is much smaller than those at 1064 nm and those of the reference compound CS{sub 2}. The <{gamma}> values at both wavelengths as a function of number… more
Date: July 1, 1995
Creator: Chen, L. X.; Mandal, B. K. & Bihari, B.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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ELECTRICAL PROPERTIES OF ORGANIC SOLIDS. I. KINETICS AND MECHANISMOF CONDUCTIVITY OF METAL-FREE PHTHALOCYANINE

Description: Techniques involving the use of high-intensity short-duration light pulses have been applied t o the study of the kinetics of photoconductivity in films of metal-free phthalocyanine. These experiments, in conjunction with measurements of steady-state photoconductivity, are consistent with the following scheme. The principal route for the formation of charge carriers is via the first excited singlet state, although the lowest triplet state can, t o some extent, contribute to charge - carrier pro… more
Date: July 29, 1959
Creator: Tollin, Gordon; Kearns, David R. & Calvin, Melvin.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Solid State Division Quarterly Progress Report: August 1952

Description: This quarterly progress report discusses the ongoing work within the Solid State Division at the Oak Ridge National Laboratory for the period ending August 10, 1952. Projects discussed include radiation metallurgy, engineering properties, fused salts, crystal physics, and solid state reactions.
Date: January 30, 1959
Creator: Billington, D. S. (Douglas S.) & Howe, J. T.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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ELECTRICAL PROPERTIES OF ORGANIC SOLIDS. II: EFFECTS OF ADDEDELECTRON ACCEPTOR ON METAL-FREE PHTHALOCYANINE

Description: The addition of ortho-chloranil to the surface of films of metal-free phthalocyanine has been found (a) to increase the dark conductivity of such films by as much as 10{sup 7}, (b) to increase the steady-state photoconductivity by as much as 10{sup 5}, and (c) to result in the formation of unpaired electrons whose concentration decreases reversibly as a result of illumination. These systems exhibit a light-induced polarization, the phthalocyanine layer becoming more positive with respect t o th… more
Date: July 29, 1959
Creator: Kearns, David R.; Tollin, Gordon & Calvin, Melvin
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Electroreduction of nitrate ions in concentrated sodium hydroxide solutions at lead, zinc, nickel, and phthalocyanine-modified electrodes

Description: The electrochemical reduction of nitrate in strongly alkaline solution has been studied using nickel, lead, zinc, and iron cathodes. Intermediate formation of nitrate ion and ammonia product was observed for all electrode materials. Coating a nickel sponge electrode with phthalocyanine renders it less active toward nitrate reduction, while iron electrodes appear to be activated. Electrolysis between a lead cathode and a nickel anode is an efficient means of removing nitrate from strongly alkali… more
Date: December 31, 1987
Creator: Li, H.; Chambers, J. Q. & Hobbs, D. T.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Probing Properties of Glassy Water and Other Liquids with Site Selective Spectroscopies

Description: The standard non-photochemical hole burning (NPHB) mechanism, which involves phonon-assisted tunneling in the electronically excited state, was originally proposed to explain the light-induced frequency change of chemically stable molecules in glassy solids at liquid helium temperatures by this research group more than two decades ago. The NPHB mechanism was then further elucidated and the concept of intrinsic to glass configurational relaxation processes as pre-mediating step to the hole burni… more
Date: August 12, 2005
Creator: Dang, Nhan Chuong
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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Construction of artificial pigment-protein antennae

Description: Photosynthesis is a complex process which results in the conversion of solar radiation into chemical energy. This chemical energy is then used as the free energy source for all living organisms. In its basic form, photosynthesis can be described as the light-activated synthesis of carbohydrates from the simple molecules of water and carbon dioxide: 6H{sub 2}O + 6 CO{sub 2} light C{sub 6}H{sub 12}O{sub 6} + 6 O{sub 2} This basic mechanism actually requires numerous reaction steps. The two primar… more
Date: January 10, 1997
Creator: Sibbald, J.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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Method of solubilizing phthalocyanines and metallophthalocyanines

Description: A one-step method of manufacturing soluble phthalocyanines and metallophthalocyanines, like zinc phthalocyanine, by converting a phthalocyanine or a metallophthalocyanine to a trialkylsilyl-substituted derivative is disclosed. The phthalocyanine or metallophthalocyanine is converted to a soluble trialkylsilyl-substituted derivative by interacting the phthalocyanine or metallophthalocyanine with an active metal amide, like lithium 2,2,6, 6-tetra-methylpiperidide, and a halotrialkylsilane, like c… more
Date: June 1, 1990
Creator: Rathke, J. W.; Chen, M. J. & Fendrick, C. M.
Item Type: Refine your search to only Patent
Partner: UNT Libraries Government Documents Department
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Resonance Raman and photophysical studies of transition metal complexes in solution and entrapped in zeolites. Progress report, August 1, 1990--January 1993

Description: Area of most intense activity involves study of effects of entrapment of ruthenium(II)-polypyridyl complexes within the supercages of Y-zeolite. Results of initial studies document alterations in photophysical properties of entrapped complexes and provide insight into the factors responsible for these changes. A second major activity was to undertake an investigation of the feasibility of entrapment of metallophthalocyanines within the Y-zeolite supercages. Initial problems in preparative metho… more
Date: September 1, 1993
Creator: Kincaid, J. R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Electrocatalysts for Oxygen Electrodes. Final Report

Description: Object was to understand factors controlling the activity of O{sub 2} reduction and generation electrocatalysts, in order to attain higher activity and longer-term stability. Two broad classes of catalysts were developed: transition metal macrocycles in monomeric and polymeric forms, and transition metal oxides including perovskites and pyrochlores. 20 refs., 14 figs.
Date: February 1, 1993
Creator: Yeager, E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Development of inexpensive metal macrocyclic complexes for use in fuel cells

Description: Several metal macrocyclic complexes were synthesized for use as catalysts in fuel cells. An initial evaluation of their ability to catalyze the fuel cell reactions were completed. Based on this initial evaluation, one metal macrocyclic catalyst was selected and long-term stability testing in a fuel cell was initiated. The fuel cell employing this catalyst was operated continuously for one year with little signs of catalyst degradation. The effect of synthetic reformates on the performance of th… more
Date: January 1, 1998
Creator: Doddapaneni, N.; Ingersoll, D.; Kosek, J.A.; Cropley, C.C. & Hamdan, M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Direct catalytic conversion of methane and light hydrocarbon gases. Quarterly report No. 1, October 16, 1986--January 15, 1987

Description: The United States will need to be able to convert coal to liquid fuels should current supplies be interrupted. The indirect method for producing fuel liquids is the gasification of the coal to synthesis gas (syngas) followed by Fischer-Tropsch synthesis to convert syngas to hydrocarbons. However, both the gasifier and the FTS processes result in the production of methane and/or light hydrocarbon by-product that negatively affect the economics of the production of liquid fuel from coal. The goal… more
Date: February 23, 1987
Creator: Wilson, R. B., Jr. & Chan, Yee Wai
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Electrocatalysts for Oxygen Electrodes. Final Report

Description: The objectives of the research were: to develop further understanding of the factors controlling O{sub 2} reduction and generation on various electrocatalysts, including transition metal macrocycles and oxides: to use this understanding to identify and develop much higher activity catalysts, both monofunction and bifunction; and to establish how catalytic activity for a given O{sub 2} electrocatalyst depends on catalyst-support interactions and to identify stable catalyst supports for bifunctio… more
Date: October 1, 1991
Creator: Yeager, E. B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Advanced separation technology for flue gas cleanup. Quarterly technical report No. 1

Description: The objective of this work is to develop a novel system for regenerable SO{sub 2} and NO{sub x} scrubbing of flue gas that focuses on (a) a novel method for regeneration of spent SO{sub 2} scrubbing liquor and (b) novel chemistry for reversible absorption of NO{sub x}. In addition, high efficiency hollow fiber contactors (HFC) are proposed as the devices for scrubbing the SO{sub 2} and NO{sub x} from the flue gas. The major cost item in existing technology is capital investment. Therefore, our … more
Date: July 1, 1992
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Advanced separation technology for flue gas cleanup. Quarterly technical report No. 14

Description: The objective of this work is to develop a novel system for regenerable SO{sub 2} and NO{sub x} scrubbing of flue gas that focuses on (a) a novel method for regeneration of spent SO{sub 2} scrubbing liquor and (b) novel chemistry for reversible absorption of NO{sub x}. In addition, high efficiency hollow fiber contactors (HFC) are proposed as the devices for scrubbing the SO{sub 2} and NO{sub x} from the flue gas. The system will be designed to remove more than 95% of the SO{sub x} and more tha… more
Date: November 1, 1995
Creator: Bhown, A. S.; Pakala, N.; Riggs, T.; Tagg, T.; Kirkar, K. K.; Majumdar, S. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Advanced separation technology for flue gas cleanup: Quarterly technical report No. 16, January 1996--March 1996

Description: The objective of this work is to develop a novel system for regenerable SO{sub 2} and NO{sub x} scrubbing of flue gas that focuses on (a) a novel method for regeneration of spent SO{sub 2} scrubbing liquor and (b) novel chemistry for reversible absorption of NO{sub x}. In addition, high efficiency hollow fiber contactors (BFC) are proposed as the devices for scrubbing the SO{sub 2} and NO{sub x} from the flue gas. The system will be designed to remove more than 95% of the SO{sub x} and more tha… more
Date: June 1, 1996
Creator: Bhown, A. S.; Bahman, A.; Sirkar, K. K.; Majumdar, S. & Bhaumick, D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Direct catalytic conversion of methane and light hydrocarbon gases. Quarterly report No. 7, April 16, 1988--July 15, 1988

Description: The goal of this research is to develop catalysts that directly convert methane and light hydrocarbons to intermediates that later can be converted to either liquid fuels or value-added chemicals, as economics dictate. During this reporting period, much of our effort focused on investigating the stability of the methane reforming catalysts (Task 2) with respect to storage time. Many of these catalysts demonstrated lessened activity when they were reexamined up to 18 months after they ere first … more
Date: August 31, 1988
Creator: Wilson, R. B., Jr.; Chan, Yee Wai & Posin, B.M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Direct Catalytic Conversion of Methane and Light Hydrocarbon Gases Quarterly Report: Number 3

Description: The goal of this research is to develop catalysts that directly convert methane and light hydrocarbons to intermediates that can, as economics dictate, be subsequently converted either to liquid fuels or value-added chemicals. In this program we are exploring two approaches to developing such catalysts. The first approach consists of developing advanced catalysts for reforming methane. We will prepare the catalysts by reacting organometallic complexes of transition metals (Fe, Ru, Rh, and Re) w… more
Date: August 28, 1987
Creator: Wilson, Robert B., Jr. & Chan, Yee Wai
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Advanced separation technology for flue gas cleanup. Quarterly technical report No. 15

Description: The objective of this work is to develop a novel system for regenerable SO{sub 2} and NO{sub x} scrubbing of flue gas that focuses on (1) a novel method for regeneration of spent SO{sub 2} scrubbing liquor and (2) novel chemistry for reversible absorption of NO{sub x}. In addition, high efficiency hollow fiber contactors (HFC) are proposed as the devices for scrubbing the SO{sub 2} and NO{sub x} from the flue gas. The system will be designed to remove more than 95% of the SO{sub x} and more tha… more
Date: February 1, 1996
Creator: Bhown, A. S.; Pakala, N.; Riggs, T. & Tagg, T.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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