Heavy Metal Containing Patents (Class 252/301.18)
  • Patent number: 11041119
    Abstract: A Europium beta-diketonate molecule comprises Europium with ligands dibenzoylmethane, 1,10-phenanthroline, and methoxide. The molecule is photoluminescent, absorbing light from the ultraviolet region through the blue region and emitting red light characteristic of trivalent europium. The molecule may be used, for example, as a phosphor in a phosphor-converted light-emitting diode.
    Type: Grant
    Filed: November 29, 2018
    Date of Patent: June 22, 2021
    Inventor: Jonathan Melman
  • Patent number: 10988494
    Abstract: To provide europium complexes having high photostability.
    Type: Grant
    Filed: November 27, 2018
    Date of Patent: April 27, 2021
    Assignees: TOSOH CORPORATION, SAGAMI CHEMICAL RESEARCH INSTITUTE
    Inventors: Keisuke Araki, Hiroya Honda, Naoyuki Koiso, Ryo Nakagame, Fumiaki Yoshitomi, Kohei Iwanaga, Taishi Furukawa
  • Patent number: 10364223
    Abstract: Provided is an organic compound, which is represented by the general formula (1): in the general formula (1), R1 and R2 are each independently selected from the group consisting of an alkyl group having 1 or more and 20 or less carbon atoms, an aryl group, an aralkyl group, and a heteroaryl group, R3 and R4 are each independently selected from an alkyl group having 1 or more and 10 or less carbon atoms, and an alkoxy group having 1 or more and 10 or less carbon atoms, and A1? and A2? each independently represent a monovalent anion.
    Type: Grant
    Filed: February 13, 2018
    Date of Patent: July 30, 2019
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Tetsuya Tamura, Satoshi Igawa
  • Patent number: 9966726
    Abstract: In various embodiments, an emission source may be provided. The emission source may also include a gain medium including a halide semiconductor material. The emission source may further include a pump source configured to provide energy to the gain medium.
    Type: Grant
    Filed: September 12, 2014
    Date of Patent: May 8, 2018
    Assignee: NANYANG TECHNOLOGICAL UNIVERSITY
    Inventors: Guichuan Xing, Nripan Mathews, Subodh Gautam Mhaisalkar, Tze Chien Sum
  • Patent number: 9499738
    Abstract: The invention relates to a solid organic scintillator comprising a polymeric matrix in which there are dispersed one or more fluorophore compounds and one or more chemical elements having an atomic number ranging from 40 to 83, characterized in that said scintillator has a weight content of said chemical elements of at least 5% by weight relative to the total weight of the scintillator, and in that the scintillator emits an emission spectrum comprising an emission peak at a wavelength of at least 550 nm.
    Type: Grant
    Filed: December 20, 2011
    Date of Patent: November 22, 2016
    Assignee: COMMISSARIAT A L'ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
    Inventors: Matthieu Hamel, Stephane Darbon, Stephane Normand, Gregory Turk
  • Patent number: 9496582
    Abstract: Various embodiments are directed to a flexible battery structure comprising patterned active layers. An example battery structure comprises a sheet of current collector material, first and second active layers, and a first electrolyte layer. The first active layer may be disposed on the sheet and may comprise a plurality of active material portions and a plurality of slots, where each of the plurality of slots separates a set of at least to adjacent active material portions.
    Type: Grant
    Filed: March 24, 2014
    Date of Patent: November 15, 2016
    Assignee: Amazon Technologies, Inc.
    Inventors: James Robert Lim, Yuting Yeh, Erik Avy Vaknine, David Wang
  • Patent number: 9296945
    Abstract: Compositions, methods, and systems related to plastic scintillating materials based on a polymer including an aromatic ring structure combined with an oxazole and a cross-linker are disclosed. The disclosed plastic scintillator materials may advantageously provide gamma-neutron pulse shape discrimination capabilities.
    Type: Grant
    Filed: April 11, 2014
    Date of Patent: March 29, 2016
    Assignee: Radiation Monitoring Devices, Inc.
    Inventors: Edgar V. Van Loef, Kanai S. Shah, Gary Markosyan
  • Publication number: 20140346400
    Abstract: A method for the synthesis and use of transparent bulk conjugated polymers prepared from liquid monomers via bulk polymerization. The liquid monomer contains pi-electron conjugated moieties and polymerizable moieties. The monomer solution may also have functionalizing additives such as a luminescence additive that includes organic dyes, luminescent molecules, fluorescent compounds, phosphorescent compounds, and luminescent quantum dots. The monomer solution may also have sensitizing additives such as high-energy photo sensitizing compounds, nanoparticles of compounds containing atoms with atomic numbers greater than 52 and neutron sensitizing additives. The monomer solution is polymerized by heating to an elevated temperature with or without addition of an initiator. Alternatively, the monomer is polymerized by photo-induced polymerization. A photoinitiator may be employed to initiate the photopolymerization. Scintillation materials with significant light yields are illustrated.
    Type: Application
    Filed: June 2, 2014
    Publication date: November 27, 2014
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Qibing Pei, Qi Chen
  • Patent number: 8698086
    Abstract: A scintillator material according to one embodiment includes a bismuth-loaded aromatic polymer having an energy resolution at 662 keV of less than about 10%. A scintillator material according to another embodiment includes a bismuth-loaded aromatic polymer having a fluor incorporated therewith and an energy resolution at 662 keV of less than about 10%. Additional systems and methods are also presented.
    Type: Grant
    Filed: June 16, 2011
    Date of Patent: April 15, 2014
    Assignee: Lawrence Livermore National Security, LLC
    Inventors: Nerine Jane Cherepy, Robert Dean Sanner, Stephen Anthony Payne, Benjamin Lee Rupert, Benjamin Walter Sturm
  • Patent number: 8663820
    Abstract: The invention relates to a printed document of value having at least one authenticity feature in the form of a luminescent substance based on doped host lattices. The host lattice has a strong crystal field and is doped with at least one chromophore with the electron configuration (3d)2.
    Type: Grant
    Filed: March 5, 2002
    Date of Patent: March 4, 2014
    Assignee: Giesecke & Devrient GmbH
    Inventors: Thomas Giering, Rainer Hoppe, Fritz Stahr
  • Publication number: 20130299742
    Abstract: The invention relates to a solid organic scintillator comprising a polymeric matrix in which there are dispersed one or more fluorophore compounds and one or more chemical elements having an atomic number ranging from 40 to 83, characterized in that said scintillator has a weight content of said chemical elements of at least 5% by weight relative to the total weight of the scintillator, and in that the scintillator emits an emission spectrum comprising an emission peak at a wavelength of at least 550 nm.
    Type: Application
    Filed: December 20, 2011
    Publication date: November 14, 2013
    Inventors: Matthieu Hamel, Stephane Darbon, Stephane Normand, Gregory Turk
  • Publication number: 20130299702
    Abstract: A scintillator material according to one embodiment includes a polymer matrix; a primary dye in the polymer matrix, the primary dye being a fluorescent dye, the primary dye being present in an amount of 3 wt % or more; and at least one component in the polymer matrix, the component being selected from a group consisting of B, Li, Gd, a B-containing compound, a Li-containing compound and a Gd-containing compound, wherein the scintillator material exhibits an optical response signature for thermal neutrons that is different than an optical response signature for fast neutrons and gamma rays. A system according to one embodiment includes a scintillator material as disclosed herein and a photodetector for detecting the response of the material to fast neutron, thermal neutron and gamma ray irradiation.
    Type: Application
    Filed: May 14, 2012
    Publication date: November 14, 2013
    Applicant: LAWRENCE LIVERMORE NATIONAL SECURITY, LLC
    Inventors: Natalia P. Zaitseva, M Leslie Carman, Michelle A. Faust, Andrew M. Glenn, H. Paul Martinez, Iwona A. Pawelczak, Stephen A. Payne, Keith E. Lewis
  • Patent number: 8530685
    Abstract: Monodentate gold ethynyl complexes having a gold-carbon bond and a gold-phosphorous bond, specifically, of formula I, may be useful in optoelectric devices, wherein Ar1 and Ar2 are independently monocyclic or polycyclic aryl, unsubstituted or substituted with one or more alkyl, alkenyl, alkoxy, aryl, aryloxy, fluoro, fluoroalkyl, or perfluoroalkyl; and R is substituted or unsubstituted aryl.
    Type: Grant
    Filed: July 30, 2012
    Date of Patent: September 10, 2013
    Assignee: General Electric Company
    Inventors: Srinivas Prasad Sista, Arunkumar Natarajan, Jie Jerry Liu, Patrick Joseph McCloskey, Joseph John Shiang
  • Publication number: 20120241630
    Abstract: Embodiments of the invention provide a scintillator material, a scintillator system, and/or a method of detecting incident radiation using a scintillator material, or scintillator system, comprising a polymer material that comprises chromophores. Additional embodiments provide a scintillator material, scintillator system, and/or a method of detecting incident radiation using a scintillator material, or scintillator system, comprising a polymer material having one, two, three, or more, organic dyes dissolved therein wherein the polymer material having the one, two, three, or more dyes dissolved therein comprises chromophores. At least one of the dyes, termed the base dye, has a concentration in the range 0.5 to 3.5 mol/L. In a specific embodiment, the base dye has a concentration in the range 1.0 to 3.0 mol/L. This base dye concentration is high enough to achieve a substantial triplet-triplet state annihilation rate despite the negligible diffusion of the dye in the rigid polymer matrix.
    Type: Application
    Filed: March 26, 2012
    Publication date: September 27, 2012
    Applicant: NANOPTICS, INCORPORATED
    Inventors: JAMES K. WALKER, YOUNGWOOK NOH, RICHARD T. FARLEY
  • Publication number: 20120235095
    Abstract: The present invention provides improved methods for preparing cetyltrimethylammonium bromide-capped gold nanoparticles through the use of hydroquinone as a reducing agent. Such methods generally comprise the steps of: (1) providing a seed solution comprising a gold nanoparticle; (2) providing an aqueous growth solution comprising: (i) cetyltrimethylammonium bromide, (ii) hydrogen tetrachloroaurate, and (iii) hydroquinone; and (3) adding a quantity of the seed solution to the aqueous growth solution.
    Type: Application
    Filed: March 15, 2012
    Publication date: September 20, 2012
    Inventors: Leonid Vigderman, Eugene R. Zubarev
  • Patent number: 8231969
    Abstract: The invention provides methods and compositions having at least one asymmetrically functionalized nanoparticle. An asymmetrically functionalized nanoparticle can comprise a nanoparticle core having an outer surface, a primary group of first ligands attached to a substantially continuous primary region of the outer surface, and a secondary group of second ligands attached to a substantially continuous secondary region of the outer surface, such that the primary group of first ligands and the secondary group of second ligands comprise a different ligand population.
    Type: Grant
    Filed: March 26, 2009
    Date of Patent: July 31, 2012
    Assignee: University of Utah Research Foundation
    Inventors: Jennifer S. Shumaker-Parry, Rajesh Sardar
  • Publication number: 20120080645
    Abstract: Disclosed are a method of growing a rare-earth oxyorthosilicate crystal and a crystal grown using the method. A melt is prepared by melting a first substance including at least one rare-earth element and a second substance including at least one element from group 7 of the periodic table. A seed crystal is brought into contact with the surface of the melt and withdrawn to grow the crystal.
    Type: Application
    Filed: September 30, 2010
    Publication date: April 5, 2012
    Applicant: SIEMENS MEDICAL SOLUTIONS USA, INC.
    Inventors: Mark S. Andreaco, A. Andrew Carey, Piotr Szupryczynski
  • Publication number: 20110315885
    Abstract: A scintillator material according to one embodiment includes a bismuth-loaded aromatic polymer having an energy resolution at 662 keV of less than about 10%. A scintillator material according to another embodiment includes a bismuth-loaded aromatic polymer having a fluor incorporated therewith and an energy resolution at 662 keV of less than about 10%. Additional systems and methods are also presented.
    Type: Application
    Filed: June 16, 2011
    Publication date: December 29, 2011
    Applicant: LAWRENCE LIVERMORE NATIONAL SECURITY, LLC
    Inventors: Nerine Jane Cherepy, Robert Dean Sanner, Stephen Anthony Payne, Benjamin Lee Rupert, Benjamin Walter Sturm
  • Patent number: 8048337
    Abstract: Disclosed are a composition comprising a mixture of at least one iridium organometallic compound and an electrically conductive polymer, an organic active layer comprising the same, an organic memory device comprising the organic active layer and methods for fabricating the same. The organic memory device may include a first electrode, a second electrode and the organic active layer between the first and second electrodes. The organic memory device possesses the advantages of rapid switching time, decreased operating voltage, decreased fabrication costs, increased reliability and improved non-volatility.
    Type: Grant
    Filed: April 6, 2007
    Date of Patent: November 1, 2011
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Kwang Hee Lee, Yi Yeol Lyu, Sang Kyun Lee
  • Patent number: 8039643
    Abstract: Disclosed are a composition comprising a mixture of at least one iridium organometallic compound and an electrically conductive polymer, an organic active layer comprising the same, an organic memory device comprising the organic active layer and methods for fabricating the same. The organic memory device may include a first electrode, a second electrode and the organic active layer between the first and second electrodes. The organic memory device possesses the advantages of rapid switching time, decreased operating voltage, decreased fabrication costs, increased reliability and improved non-volatility.
    Type: Grant
    Filed: July 30, 2010
    Date of Patent: October 18, 2011
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Kwang Hee Lee, Yi Yeol Lyu, Sang Kyun Lee
  • Patent number: 7857993
    Abstract: Applicant's present invention is a composite scintillator having enhanced transparency for detecting ionizing radiation comprising a material having optical transparency wherein said material comprises nano-sized objects having a size in at least one dimension that is less than the wavelength of light emitted by the composite scintillator wherein the composite scintillator is designed to have selected properties suitable for a particular application.
    Type: Grant
    Filed: September 14, 2004
    Date of Patent: December 28, 2010
    Assignees: UT-Battelle, LLC, BWXT Y-12, LLC
    Inventors: Sheng Dai, Andrew Curtis Stephan, Suree S. Brown, Steven A. Wallace, Adam J. Rondinone
  • Patent number: 7675039
    Abstract: A phosphor sheet 8 for a radiation detector used by being attached to a photoelectric conversion film 20 of a radiation detector 4 includes a sheet-shaped support 11, and a phosphor layer 12 provided thereon. The phosphor layer 12 contains a europium-activated rare earth oxysulfide phosphor having a europium concentration in a range of 0.01 to 3.5 mol %. The radiation detector 4 includes the phosphor sheet 8 being irradiated with radiation rays transmitted through a specimen and converting the radiation rays into light, a photoelectric conversion film 20 for converting the light from the phosphor sheet 8 into electric charges, and a charge information reading section 30 for reading out the charges generated on the photoelectric conversion film 20 for each of a plurality of pixels 31.
    Type: Grant
    Filed: September 25, 2003
    Date of Patent: March 9, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Eiji Oyaizu, Masami Okamura
  • Publication number: 20090256116
    Abstract: The invention provides methods and compositions having at least one asymmetrically functionalized nanoparticle. An asymmetrically functionalized nanoparticle can comprise a nanoparticle core having an outer surface, a primary group of first ligands attached to a substantially continuous primary region of the outer surface, and a secondary group of second ligands attached to a substantially continuous secondary region of the outer surface, such that the primary group of first ligands and the secondary group of second ligands comprise a different ligand population.
    Type: Application
    Filed: March 26, 2009
    Publication date: October 15, 2009
    Inventors: Jennifer S. Shumaker-Parry, Rajesh Sardar
  • Patent number: 7582363
    Abstract: The present invention provides an organic polymer light-emitting element material having a gold complex structure as a part of the side chain or crosslinking group as represented by formulae (5) and (8) and an organic polymer light-emitting element comprising layer(s) comprising the organic polymer light-emitting element material. The present invention provides a polymer-based phosphorescent material useful for a multicolor or white light-emitting organic EL device having high luminous efficiency and capable of large-area formation and mass production.
    Type: Grant
    Filed: April 28, 2004
    Date of Patent: September 1, 2009
    Assignee: Showa Denko K.K.
    Inventors: Yoshiaki Takahashi, Isamu Taguchi, Koro Shirane
  • Patent number: 7563898
    Abstract: Disclosed are iridium-based luminescent compounds having phenylpyridine moieties with an organosilicon group, and organic electroluminescence devices using the compounds as color-producing materials.
    Type: Grant
    Filed: October 3, 2005
    Date of Patent: July 21, 2009
    Assignee: LG Display Co., Ltd.
    Inventors: Jeong Dae Seo, Chun Gun Park, Soon Ki Kwon, Yun Hi Kim, Sung Ouk Jung, Jun Hwan Ahn, Hyung Sun Kim
  • Patent number: 7560046
    Abstract: A sintered, annealed scintillator composition, which, prior to annealing, has a formula of A3B2C3O12, where A is at least one member of the group consisting of Tb, Ce, and Lu, or combinations thereof, B is an octahedral site (Al), and C is a tetrahedral site (also Al). One or more substitutions are included. The substitutions may may be partial or, in some cases, complete, and can include Al with Sc at B, up to two atoms of oxygen with fluorine and the same number of Ca atoms at A, replacement at B with Mg and the same number of atoms of oxygen with fluorine, replacement at B with a combination of Mg/Si Mg/Zr, Mg/Ti, and/or Mg/Hf, replacement at B with a combination of Li/Nb and/or Li/Ta, and at A with Ca and replacement of an equal number of B or C with silicon.
    Type: Grant
    Filed: December 22, 2005
    Date of Patent: July 14, 2009
    Assignee: General Electric Company
    Inventors: Robert Joseph Lyons, Venkat Subramaniam Venkataramani, Anant Achyut Setlur
  • Publication number: 20080217582
    Abstract: A new class of luminescent iridium(III) complexes, luminescent material and organic electroluminescent device thereof had been disclosed. The novel luminescent iridium(III) complexes comprises the formula [(C?N)2Ir(P?O)] with 2-(diphenylphosphino)phenolate as the ancillary chelate. The iridium complexes of the present invention can be used as the red, blue or green-emitting dopants. These luminescent materials can be applied in the fabrication of light-emitting layer of organic electroluminescent devices and providing the high efficiently red, blue or green light organic electroluminescent devices of commercial pursuits.
    Type: Application
    Filed: March 8, 2007
    Publication date: September 11, 2008
    Inventors: Yun Chi, Pi-Tai Chou, Yi-Hwa Song, Yuan-Chieh Chiu, Chiung-Fang Chang
  • Publication number: 20080191168
    Abstract: An improved nanophosphor scintillator liquid comprises nanophosphor particles in a liquid matrix. The nanophosphor particles are optionally surface modified with an organic ligand. The surface modified nanophosphor particle is essentially surface charge neutral, thereby preventing agglomeration of the nanophosphor particles during dispersion in a liquid scintillator matrix. The improved nanophosphor scintillator liquid may be used in any conventional liquid scintillator application, including in a radiation detector.
    Type: Application
    Filed: October 25, 2007
    Publication date: August 14, 2008
    Applicant: LOS ALAMOS NATIONAL SECURITY, LLC
    Inventors: Edward Allen MCKIGNEY, Anthony Keiran Burrell, Bryan L. Bennett, David Wayne Cooke, Kevin Curtis Ott, Minesh Kantilal Bacrania, Rico Emilio Del Sesto, Robert David Gilbertson, Ross Edward Muenchausen, Thomas Mark McCleskey
  • Patent number: 7087904
    Abstract: This invention is a positron emission tomography (PET) device comprising as a scintillator a perovskite organic/inorganic hybrid compound selected from the group represented by the general formulae: (R1—NR113)2MX4 or (R2—NR12)2MX4, (NR133—R3—NR133)MX4, or (NR142?R4?NR142)MX4, or AMX3. When used as a scintillator, the perovskite organic/inorganic hybrid compound emits visible light with a very fast (subnanosecond order) response, allowing for improved resolution and time-of-flight PET methods.
    Type: Grant
    Filed: July 29, 2002
    Date of Patent: August 8, 2006
    Assignee: Japan Science and Technology Agency
    Inventors: Kengo Shibuya, Masanori Koshimizu, Keisuke Asai
  • Patent number: 6911251
    Abstract: An optically nonisotropic composite material. The composite material includes two materials, a transparent bulk optical material and radiation absorbing or reflecting fibers embedded within the bulk material. The fibers are substantially parallel to one another and tend to channel the radiation along the direction of the fibers. The bulk material may be a scintillator, in which case the fibers will tend to channel scintillating radiation along the direction of the fibers. The composite material may be used in a high spatial resolution x-ray device, such as a CT scanner. The composite material may also be used in an electromagnetic radiation detection device. Advantageously, the fibers tend to channel radiation along the fibers towards photodetector cells of the radiation detection device thereby increasing spatial resolution.
    Type: Grant
    Filed: March 15, 2002
    Date of Patent: June 28, 2005
    Assignee: General Electric Company
    Inventor: Steven Jude Duclos
  • Patent number: 6911551
    Abstract: The present invention relates to substituted boron or aluminum spiro compounds and their use in the electronic industry. The compounds of the invention are used as electron transport material, hole blocking material and/or as host material in organic electroluminescence and/or phosphorescence devices, as electron transport material in photocopiers, as electron acceptor or electron transport material in solar cells, as charge transport material in organic ICs (circuits) and in organic solid-state lasers or organic photodetectors.
    Type: Grant
    Filed: December 20, 2001
    Date of Patent: June 28, 2005
    Assignee: Covion Organic Semiconductors GmbH
    Inventors: Philipp Stössel, Hubert Spreitzer, Heinrich Becker, Jacqueline Drott
  • Publication number: 20040084654
    Abstract: This invention relates to a radiation detection device for detecting ionizing beam discharges such as gamma rays, x-rays, electron beams, charged particle beams and neutral particle beams. Specifically, it relates to a radiation detection device which can measure radiations which exist for a very short time (of the order of subnanoseconds or less) from the appearance of photoemission to extinction.
    Type: Application
    Filed: July 29, 2002
    Publication date: May 6, 2004
    Inventors: Kengo Shibuya, Masanori Koshimizu, Yuko Takeoka, Keisuke Asai
  • Patent number: 6544442
    Abstract: Disclosed is a composition of matter comprising a tributyl phosphate complex of a group 3, lanthanide, actinide, or group 13 salt in an organic carrier and a method of making the complex. These materials are suitable for use in solid or liquid organic scintillators, as in x-ray absorption standards, x-ray fluorescence standards, and neutron detector calibration standards.
    Type: Grant
    Filed: September 22, 1999
    Date of Patent: April 8, 2003
    Assignee: UT-Battelle, LLC
    Inventors: Zane W. Bell, Chuen Huei-Ho, Gilbert M. Brown, Charles Hurlbut
  • Patent number: 6471888
    Abstract: Simultaneous measurement of neutron flux and temperature is provided by a single sensor which includes a phosphor mixture having two principal constituents. The first constituent is a neutron sensitive Li6F and the second is a rare-earth activated Y2O3 thermophosphor. The mixture is coated on the end of a fiber optic, while the opposite end of the fiber optic is coupled to a light detector. The detected light scintillations are quantified for neutron flux determination, and the decay is measured for temperature determination.
    Type: Grant
    Filed: December 12, 1995
    Date of Patent: October 29, 2002
    Assignee: UT-Battelle, LLC
    Inventors: John T. Mihalczo, Marc L. Simpson, Stephanie A. McElhaney
  • Patent number: 6410766
    Abstract: A series of emitting materials used for organic EL based on tridentate ligands are characterized as Formula 1, Formula 2 and Formula 3, where: the group O-I-N is a bidentate ligand such as 8-hydroxyquinoline and 2-(o-hydroxyphenyl)-benzoxazole, II, III are unsubstituted or substituted aryl groups. The substituted groups can have 1-8 carbon atoms, halogen, cyano, amino, amido, sulfonyl, carbonyl, aryl, or heteroalkyl groups. The ligand including II and III is a tridentate ligand with three chelate atoms: two oxygen atoms and one nitrogen atom. The central metal atoms can be trivalent or tetravalent atoms such as Al, In, Ga, Tl, and Sn. These materials can be used as emitting materials or electronic transport materials in organic EL devices.
    Type: Grant
    Filed: January 5, 2001
    Date of Patent: June 25, 2002
    Assignee: Tsinghau University
    Inventors: Yong Qiu, Yan Shao
  • Patent number: 6288229
    Abstract: A ruthenium (II) complex having a dipyridophenazine or tetrapyridophenazine ligand and being represented by the formula (1) or (2) shown in the specification. Upon absorption of light, the complex emits fluorescence for a longer life time in a protic solvent as compared with known analogous compounds.
    Type: Grant
    Filed: March 27, 2000
    Date of Patent: September 11, 2001
    Assignee: Secretary of Agency of Industrial Science and Technology
    Inventors: Nobuko Komatsuzaki, Ryuzi Katoh, Yuichiro Himeda, Hideki Sugihara, Hironori Arakawa, Kazuyuki Kasuga