DOCSLIB.ORG

2,5,8-Trihydrazino-S-Heptazine

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
2,5,8-Trihydrazino-S-Heptazine 2,5,8-Trihydrazino-s-heptazine: a precursor for heptazine-based iminophosphoranes Edwin Kroke, Tatyana Saplinova, Vadym Bakumov, Tobias Gmeiner, Jörg Wagler, Marcus Schwarz To cite this version: Edwin Kroke, Tatyana Saplinova, Vadym Bakumov, Tobias Gmeiner, Jörg Wagler, et al.. 2,5,8- Trihydrazino-s-heptazine: a precursor for heptazine-based iminophosphoranes. Journal of Inorganic and General Chemistry / Zeitschrift für anorganische und allgemeine Chemie, Wiley-VCH Verlag, 2009, 10.1002/zaac.200900311. hal-00518304 HAL Id: hal-00518304 https://hal.archives-ouvertes.fr/hal-00518304 Submitted on 17 Sep 2010 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. ZAAC 2,5,8-Trihydrazino-s-heptazine: a precursor for heptazine- based iminophosphoranes Journal: Zeitschrift für Anorganische und Allgemeine Chemie Manuscript ID: zaac.200900311.R1 Wiley - Manuscript type: Article Date Submitted by the 17-Jul-2009 Author: Complete List of Authors: Kroke, Edwin; TU Bergakademie Freiberg, Institut fuer Anorganische Chemie Saplinova, Tatyana; TU Bergakademie Freiberg, Institut fuer Anorganische Chemie Bakumov, Vadym; Swiss Federal Laboratories for Materials Testing and Research, Laboratory for High Performance Ceramics Gmeiner, Tobias; Universität Konstanz, FB Chemie Wagler, Jörg; TU Bergakademie Freiberg, Institut fuer Anorganische Chemie Schwarz, Marcus; TU Bergakademie Freiberg, Institut fuer Anorganische Chemie Keywords: Heterocycle, Tri-s-triazine , Hydrazine, Azide, Phosphazene Wiley-VCH Page 1 of 21 ZAAC 1 2 3 4 2,5,8-Trihydrazino-s-heptazine: a precursor for heptazine-based 5 6 iminophosphoranes 7 8 9 10 11 Tatyana Saplinova, [a] Vadym Bakumov,[b] Tobias Gmeiner,[c] Jörg Wagler,[a] Marcus 12 [a] [a] 13 Schwarz, Edwin Kroke* 14 15 16 17 Keywords : Heterocycle; s-Heptazine; Hydrazine; Azide; Phosphazenes; Crystal structure 18 19 20 21 Abstract: The title compound 1 C 6N7(NHNH 2)3 was obtained from melem C 6N7(NH 2)3 or 22 melon [C 6N7(NH 2)NH] n and hydrazine via an autoclave synthesis. Upon treatment with a 23 24 10 % HCl solution it is transformed into the trihydrochloride 2, [C6N7(NHNH 3)3]Cl 3. 25 Compounds 1 and 2 were analysed with 13 C NMR, 15 N NMR, FTIR- and Raman- 26 27 spectroscopy. Furthermore, the single crystal X-ray structure of the pentahydrate of 2 is 28 reported ( P-1, a = 674.96(3), b = 1214.17(6), c = 1272.15(6) pm, α = 66.288(2)°, 29 6 3 30 β = 75.153(2)°, γ = 80.420(2)°, V = 920.30(8) · 10 pm , Z = 2, T = 90(2) K). The thermal 31 decomposition of 1 and 2 was investigated with TG/DTA. Reaction of 1 with NaNO /HCl 32 2 n 33 yields triazido-s-heptazine, C 6N7(N 3)3 3. Tris(tri butylphosphinimino)-s-heptazine 4 was 34 13 31 1 35 synthesized from 3 and characterised by means of C, P, H NMR, FTIR and MALDI-TOF 36 spectroscopy. Similar to s-heptazine derivative 3, compounds 1 and 4 are precursors for 37 38 graphitic carbon nitrides, which have attracted considerable attention recently, and to various 39 potential applications, such as flame retardants and (photo)catalysis. 40 41 42 43 44 45 [a] T. Saplinova, Dr. J. Wagler, Dr. M. Schwarz, Prof. Dr. E. Kroke 46 Institut für Anorganische Chemie, TU Bergakademie Freiberg 47 Leipziger Strasse 29, D-09596 Freiberg (Germany) 48 Fax: (+49)3731-39-4058 49 E-mail: [email protected] 50 51 [b] V. Bakumov 52 Now with: EMPA Swiss Federal Laboratories for Materials Testing and Research 53 Laboratory for High Performance Ceramics 54 Ueberlandstrasse 129 55 CH-8600 Duebendorf (Switzerland) 56 57 [c] T. Gmeiner 58 FB Chemie, Universität Konstanz 59 D-78457 Konstanz (Germany) 60 1 Wiley-VCH ZAAC Page 2 of 21 1 2 3 Introduction 4 5 6 Within the last decade numerous publications addressed the preparation of carbon 7 nitride materials.[1] Binary compounds with C N stoichiometry and 3D structure are 8 3 4 9 postulated to exhibit very specific physicochemical properties, in particular their hardness is 10 11 expected to exceed that of diamond. [2] 12 [3] 13 Among potential precursors for graphitic CN x materials, s-heptazine based 14 [4,5] [6] [7] [1g,8] 15 compounds, such as trichloro-s-heptazine, triazido-s-heptazine, melem and melon 16 attracted considerable interest in recent years. Here we report on the melem-related nitrogen- 17 18 rich substance 2,5,8-trihydrazino-s-heptazine 1 (Scheme 1). Although the synthesis of 1 has 19 [9] 20 been described in a patent in 1965, its further characterization was missing yet. 21 22 23 24 25 NH NH2 26 27 N N 28 29 30 H2N NH N NH NH2 31 32 2,4,6-trihydrazino-s-triazine 33 34 35 NH NH2 3+ 36 NH NH3 37 N N 38 N N 39 - 40 N N N 3Cl 41 N N N 42 H2N NHN N NH NH2 43 H3N NHN N NH NH3 44 45 2,5,8-trihydrazino-s-heptazine, 1 2,5,8-trihydrazino-s-heptazine trihydrochloride, 2 46 47 48 Scheme 1. 49 50 51 52 53 This fact becomes especially intriguing, when compared to the s-triazine derivative the 2,4,6- 54 55 trihydrazino-s-triazine (Scheme 1). The latter is a well known substance (its crystal structure 56 [10] 57 has been determined already in 1976) which found broad application in synthetic and 58 59 coordination chemistry. For instance, a variety of compounds combining the triazine core and 60 [11] different functional groups, such as CN, COOR, CH 2OH, CONH 2, N=N–R (R = alkyl, aryl)[12,13] can be obtained from 2,4,6-trihydrazino-s-triazine. Furthermore, it can act as a 2 Wiley-VCH Page 3 of 21 ZAAC 1 2 3 poly-dentate ligand, giving complexes with transition metals, such as Co(II), Ni(II), Cu(I), 4 [14] 5 and Zn(II). Zn(II) complexes of C 3N3(NHN=C(CH 3)2)3 were investigated for their non- 6 [15] 7 linear optic (NLO) properties. The industrial application of 2,4,6-trihydrazino-s-triazine as 8 9 a blowing agent in polymer industry for producing plastic foams is a consequence of its 10 ability to produce gaseous products by thermal decomposition. [16] 11 12 Contrary to 2,4,6-trihydrazino-s-triazine, compound 1 exhibits poor solubility in water and 13 14 organic solvents (dmf, dmso). In addition, chemical inactivity of its hydrazine groups (see 15 16 Results and Discussion) and relatively low yield of the reported procedure (27 %) are the 17 18 possible reasons for scant knowledge about 1. 19 During our investigation we improved the synthesis procedure of 1 (yield 47 %). The 20 21 crystal structure of 2,5,8-trihydrazino-s-heptazine trihydrochloride pentahydrate 2 was 22 23 determined by X-ray single crystal diffraction. Furthermore, the 2,5,8-triazido-s-heptazine 3, 24 25 an important intermediate to CN x-compounds and chemically-interesting substance, was 26 obtained by reaction of 1 with sodium nitrite in HCl-solution. One of the applications of 3 is a 27 28 synthesis of heptazine-based iminophosphoranes via the Staudinger reaction; [17] the latter 29 [18,20] 30 were suggested as halogen-free flame retardants for plastics. In this context, compound 4, 31 n 32 tris(tri butylphosphinimino)-s-heptazine, was synthesized by the Staudinger reaction of 3 with 33 n 34 tri butylphosphine. 35 36 37 38 Results and Discussion 39 40 The 2,5,8-trihydrazino-s-heptazine 1 was synthesized analogously to the reported 41 procedure,[9] while the reaction conditions were slightly modified (see Experimental Section). 42 43 The reaction was carried out according to Scheme 2. Two types of heptazine-containing 44 45 starting materials, i. e. melem and melon, can be engaged. This variation of starting materials 46 47 does not have any influence on the purity and yield of product 1. 48 2,5,8-trihydrazino-s-heptazine is a yellowish solid, which decomposes (changes its 49 50 colour to dark-brown) without melting at about 300°C and proved soluble in diluted mineral 51 52 acids, such as HCl, H 3PO 4, H 2SO 4, HNO 3. Contrary to our expectations, the nucleophilicity of 53 54 the terminal amino groups of hydrazine substituents in 1 is somewhat lower than in melem. 55 56 Besides Uhl et al. have performed several attempts to investigate reactivity of 1 towards 57 aluminium alkyls, aiming for alkylaluminium hydrazides.[19] Unfortunately, all reactions to 58 59 yield the expected product failed. Furthermore, our attempt to perform the Kirsanov reaction 60 [18,20] between 1 and PCl 5 failed, whereas this reaction route proceeds perfectly with melem. 3 Wiley-VCH ZAAC Page 4 of 21 1 2 3 One possible explanation is an involvement of the amino groups of 1 into strong hydrogen 4 5 bonding. 6 7 8 NH2 9 10 N N 11 12 N N N 13 NH NH 14 2 15 H2N N N NH2 16 N N 17 3 N2H4 H2O 18 N N N autoclave 19 NH2 20 H2N NHN N NH NH2 21 N N 22 1 23 24 N N N 25 26 HN N N NH 27 28 29 30 Scheme 2.
Load more

Recommended publications
  • Facile Synthesis of Potassium Poly(Heptazine Imide) (PHIK)
    Subscriber access provided by CORNELL UNIVERSITY LIBRARY Article Facile synthesis of potassium poly(heptazine imide) (PHIK) / Ti-based Metal- Organic Framework (MIL-125-NH2) composites for photocatalytic applications Nicolás Artemio Rodríguez, Aleksandr Savateev, Maria Alejandra Grela, and Dariya Dontsova ACS Appl. Mater. Interfaces, Just Accepted Manuscript • Publication Date (Web): 13 Jun 2017 Downloaded from http://pubs.acs.org on June 14, 2017 Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.
    [Show full text]
  • Solar Energy Harvesting with Carbon Nitrides: Do We Understand The
    Solar energy harvesting with carbon nitrides: Do we understand the mechanism? Wolfgang Domcke1, Johannes Ehrmaier1 and Andrzej L. Sobolewski2 1 Department of Chemistry, Technical University of Munich, D-85747 Garching, Germany 2 Institute of Physics, Polish Academy of Sciences, 02-668 Warsaw, Poland Email: [email protected] (Wolfgang Domcke) Abstract The photocatalytic splitting of water into molecular hydrogen and molecular oxygen with sunlight is the dream reaction for solar energy conversion. Since decades, transition-metal- oxide semiconductors and supramolecular organometallic structures have been extensively explored as photocatalysts for solar water splitting. More recently, polymeric carbon nitride materials consisting of triazine or heptazine building blocks have attracted considerable attention as hydrogen-evolution photocatalysts. The mechanism of hydrogen evolution with polymeric carbon nitrides is discussed throughout the current literature in terms of the familiar concepts developed for photoelectrochemical water splitting with semiconductors since the 1970s. We discuss in this perspective an alternative mechanistic paradigm for photoinduced water splitting with carbon nitrides, which focusses on the specific features of the photochemistry of aromatic N-heterocycles in aqueous environments. It is shown that a water molecule which is hydrogen-bonded to an N-heterocycle can be decomposed into hydrogen and hydroxyl radicals by two simple sequential photochemical reactions. This concept is illustrated by first-principles calculations of excited-state reaction paths and their energy profiles for hydrogen-bonded complexes of pyridine, triazine and heptazine with a water molecule. It is shown that the excited-state hydrogen-transfer and hydrogen-detachment reactions are essentially barrierless, in sharp contrast to water oxidation in the electronic ground state, where high barriers prevail.
    [Show full text]
  • Photo-Induced Phenomena from the Quantum Chemist Point of View Tangui Le Bahers
    Photo-Induced Phenomena from the Quantum Chemist Point of View Tangui Le Bahers To cite this version: Tangui Le Bahers. Photo-Induced Phenomena from the Quantum Chemist Point of View. Theoretical and/or physical chemistry. Université Claude Bernard Lyon 1, 2018. tel-02073756 HAL Id: tel-02073756 https://hal.archives-ouvertes.fr/tel-02073756 Submitted on 22 Mar 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. MEMOIRE En vue de l’obtention du diplôme national de l’ Habilitation à diriger des recherches, délivré par l’Université Claude Bernard Lyon 1 Discipline : Chimie Laboratoire de Chimie de l’ENS Lyon Présenté publiquement le 14 Juin 2018 Par Monsieur Tangui LE BAHERS Photo-Induced Phenomena from the Quantum Chemist Point of View Devant le jury composé de : Dr. Valérie Keller CNRS / Université de Strasbourg Pr. Mario Barbatti Université d’Aix-Marseille Dr. Pascal Raybaud IFP Energies Nouvelles Dr. Filippo De Angelis CNR Perugia / Italy Pr. Christophe Morell Université Claude Bernard Lyon 1 Dr. Chantal Andraud CNRS / ENS Lyon Remerciements Voilà maintenant 7 ans que j’ai soutenu ma thèse. Ce manuscrit vient retracer les travaux scientifiques que j’ai réalisés depuis.
    [Show full text]
  • Melamine from China and Trinidad and Tobago
    Melamine from China and Trinidad and Tobago Investigation Nos. 701-TA-526-527 and 731-TA-1262-1263 (Final) Publication 4585 December 2015 U.S. International Trade Commission Washington, DC 20436 U.S. International Trade Commission COMMISSIONERS Meredith M. Broadbent, Chairman Dean A. Pinkert, Vice Chairman Irving A. Williamson David S. Johanson F. Scott Kieff Rhonda K. Schmidtlein Elizabeth Haines Acting Director of Operations Staff assigned Cynthia Trainor, Investigator Carolyn Carlson, Investigator Philip Stone, Industry Analyst Lauren Gamache, Economist Justin Jee, Accountant Mara Alexander, Statistician Russell Duncan, Statistician Carolyn Holmes, Statistical Assistant Nataline Viray-Fung, Attorney Jane Dempsey, Attorney James McClure, Supervisory Investigator Frederick Ruggles, Supervisory Investigator Address all communications to Secretary to the Commission United States International Trade Commission Washington, DC 20436 U.S. International Trade Commission Washington, DC 20436 www.usitc.gov Melamine from China and Trinidad and Tobago Investigation Nos. 701-TA-526-527 and 731-TA-1262-1263 (Final) Publication 4585 December 2015 CONTENTS Page Determinations ....................................................................................................................... 1 Views of the Commission ........................................................................................................ 3 Part I: Introduction ...............................................................................................................
    [Show full text]
  • From Triazine to Heptazine: Origin of Graphitic Carbon Nitride As A
    This is an open access article published under an ACS AuthorChoice License, which permits copying and redistribution of the article or any adaptations for non-commercial purposes. http://pubs.acs.org/journal/acsodf Article From Triazine to Heptazine: Origin of Graphitic Carbon Nitride as a Photocatalyst Nan Liu, Tong Li, Ziqiong Zhao, Jing Liu, Xiaoguang Luo, Xiaohong Yuan, Kun Luo, Julong He, Dongli Yu,* and Yuanchun Zhao* Cite This: ACS Omega 2020, 5, 12557−12567 Read Online ACCESS Metrics & More Article Recommendations *sı Supporting Information ABSTRACT: Graphitic carbon nitride (g-CN) has emerged as a promising metal-free photocatalyst, while the catalytic mechanism for the photoinduced redox processes is still under investigation. Interestingly, this heptazine-based polymer optically behaves as a “quasi-monomer”. In this work, we explore upstream from melem (the heptazine monomer) to the triazine-based melamine and melam and present several lines of theoretical/experimental evidence where the catalytic activity of g-CN originates from the electronic structure evolution of the C−N heterocyclic cores. Periodic density functional theory calculations reveal the strikingly different electronic structures of melem from its triazine-based counterparts. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy also provide consistent results in the structural and chemical bonding variations of these three relevant compounds. Both melam and melem were found to show stable photocatalytic activities, while the photocatalytic activity of melem is about 5.4 times higher than that of melam during the degradation of dyes under UV−visible light irradiation. In contrast to melamine and melam, the frontier electronic orbitals of the heptazine unit in melem are uniformly distributed and well complementary to each other, which further determine the terminal amines as primary reduction sites.
    [Show full text]
  • Graphitic Carbon Nitride (G-C3N4), an Organic Semiconductor That Proved a Suitable Photocatalyst for Hydrogen Production from Water
    METAL LOADED G-C₃N₄ FOR VISIBLE LIGHT-DRIVEN H₂ PRODUCTION Federica Fina A Thesis Submitted for the Degree of PhD at the University of St Andrews 2014 Full metadata for this item is available in St Andrews Research Repository at: http://research-repository.st-andrews.ac.uk/ Please use this identifier to cite or link to this item: http://hdl.handle.net/10023/6322 This item is protected by original copyright This item is licensed under a Creative Commons Licence Metal loaded g-C3N4 for visible light-driven H2 production by Federica Fina A thesis submitted in partial fulfilment for the degree of PhD at the University of St Andrews 2014 I, Federica Fina hereby certify that this thesis, which is approximately 50,000 words in length, has been written by me, and that it is the record of work carried out by me and that it has not been submitted in any previous application for a higher degree. I was admitted as a research student in January 2011 and as a candidate for the degree of Doctor of Philosophy in August 2014; the higher study for which this is a record was carried out in the University of St Andrews between 2011 and 2014. Date …………….………….. Signature of candidate …………….………….. I hereby certify that the candidate has fulfilled the conditions of the Resolution and Regulations appropriate for the degree of Doctor of Philosophy in the University of St Andrews and that the candidate is qualified to submit this thesis in application for that degree. Date …………….………….. Signature of supervisor …………….………….. In submitting this thesis to the University of St Andrews I understand that I am giving permission for it to be made available for use in accordance with the regulations of the University Library for the time being in force, subject to any copyright vested in the work not being affected thereby.
    [Show full text]
  • Ab-Initio Spectroscopic Characterization of Melem-Based Graphitic Carbon Nitride Polymorphs
    nanomaterials Article Ab-Initio Spectroscopic Characterization of Melem-Based Graphitic Carbon Nitride Polymorphs Aldo Ugolotti and Cristiana Di Valentin * Dipartimento di Scienza dei Materiali, Università degli Studi di Milano-Bicocca, Via Cozzi 55, 20125 Milano, Italy * Correspondence: [email protected] Abstract: Polymeric graphitic carbon nitride (gCN) compounds are promising materials in photoacti- vated electrocatalysis thanks to their peculiar structure of periodically spaced voids exposing reactive pyridinic N atoms. These are excellent sites for the adsorption of isolated transition metal atoms or small clusters that can highly enhance the catalytic properties. However, several polymorphs of gCN can be obtained during synthesis, differing for their structural and electronic properties that ultimately drive their potential as catalysts. The accurate characterization of the obtained material is critical for the correct rationalization of the catalytic results; however, an unambiguous experimental identification of the actual polymer is challenging, especially without any reference spectroscopic features for the assignment. In this work, we optimized several models of melem-based gCN, taking into account different degrees of polymerization and arrangement of the monomers, and we present a thorough computational characterization of their simulated XRD, XPS, and NEXAFS spectroscopic properties, based on state-of-the-art density functional theory calculations. Through this detailed study, we could identify the peculiar fingerprints of each model and correlate them with its structural and/or electronic properties. Theoretical predictions were compared with the experimental data Citation: Ugolotti, A.; Di Valentin, C. whenever they were available. Ab-Initio Spectroscopic Characterization of Melem-Based Keywords: graphitic carbon nitride; melon; melem polymerization; XPS; NEXAFS; XRD; DFT; Graphitic Carbon Nitride surface science Polymorphs.
    [Show full text]
  • BERM-14 Program with Abstracts
    14th14th InternationalInternational SymposiumSymposium onon BiologicalBiological andand EnvironmentalEnvironmental Reference Materials October 11-15, 2015 Gaylord National Resort & Convention Center National Harbor, Maryland 20745 USA Explore the New Analytical Standards Portal Our portfolio of over 16,000 products includes standards for environmental, petrochemical, pharmaceutical, clinical diagnostic and toxicology, forensic, food and beverage, GMO standards, cosmetic, veterinary and much more, as well as OEM and custom products and services. All standard manufacturing sites are, at a minimum, double accredited to ISO/IEC 17025 and ISO Guide 34, which is the highest achievable quality level for reference material producers. Visit: sigma-aldrich.com/standards 3 Table of Contents BERM History . 4 General Information . 7 Exhibitor Floor Plan . .10 Plenary Speakers . .11 Keynote Speakers . .14 Technical Sessions . 19 Oral Sessions . .23 Poster Sessions . .55 Partners and Exhibitors . .92 Certified Spiking Solutions® Certified Reference Materials Cerilliant.com © 2015 Cerilliant Corporation BERM 07/15 4 BERM History The Evolution of the BERM Series of Symposia (1983-2015) BERM: a symposium with its origins in Biological and Environmental samples and the associated analytical challenges. At BRM 3 the deci- chemical metrology has evolved and extended its reach over a 32- sion was taken to change the name of the series to BERM, the addition- year lifespan, and now touches almost every field of chemical mea- al “E” reflecting the rapid growth of interest in Environmental analysis. surement. Certified Reference Materials (CRMs) have always been at The responsibility for organizing BERM 4 fell back on Dr. Wolf and it the heart of the Symposium; in particular, their preparation, use and took place in Orlando, Florida, (USA), in February 1990.
    [Show full text]
  • Some Chemicals That Cause Tumours of the Urinary Tract in Rodents Some Chemicals That Cause Tumours of the Urinary Tract in Rodents Volume 119
    SOME CHEMICALS THAT CAUSE TUMOURS SOME CHEMICALS THAT OF THE URINARY TRACT IN RODENTS TRACT IN RODENTS OF THE URINARY SOME CHEMICALS THAT CAUSE TUMOURS OF THE URINARY TRACT IN RODENTS VOLUME 119 IARC MONOGRAPHS ON THE EVALUATION OF CARCINOGENIC RISKS TO HUMANS SOME CHEMICALS THAT CAUSE TUMOURS OF THE URINARY TRACT IN RODENTS VOLUME 119 This publication represents the views and expert opinions of an IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, which met in Lyon, 6–13 June 2017 LYON, FRANCE - 2019 IARC MONOGRAPHS ON THE EVALUATION OF CARCINOGENIC RISKS TO HUMANS IARC MONOGRAPHS In 1969, the International Agency for Research on Cancer (IARC) initiated a programme on the evaluation of the carcinogenic risk of chemicals to humans involving the production of critically evaluated monographs on individual chemicals. The programme was subsequently expanded to include evaluations of carcinogenic risks associated with exposures to complex mixtures, lifestyle factors and biological and physical agents, as well as those in specific occupations. The objective of the programme is to elaborate and publish in the form of monographs critical reviews of data on carcinogenicity for agents to which humans are known to be exposed and on specific exposure situations; to evaluate these data in terms of human risk with the help of international working groups of experts in carcinogenesis and related fields; and to indicate where additional research efforts are needed. The lists of IARC evaluations are regularly updated and are available on the Internet athttp:// monographs.iarc.fr/. This programme has been supported since 1982 by Cooperative Agreement U01 CA33193 with the United States National Cancer Institute, Department of Health and Human Services.
    [Show full text]
  • Triazine-Based Carbon Nitrides for Visible-Light-Driven Hydrogen Evolution
    Triazine-based Carbon Nitrides for Visible-Light-Driven Hydrogen Evolution K. Schwinghammer, B. Tuffy, M. B. Mesch, E. Wirnhier, C. Martineau, F. Taulelle, W. Schnick, J. Senker, and B. V. Lotsch The efficient conversion of solar energy into chemical energy is a major challenge of modern materials chemistry and energy research. One solution to the future’s energy demands will be the generation of hydrogen by photochemical water splitting as an environmentally clean energy carrier with a high energy density. So far the majority of photocatalysts are of an inorganic nature containing heavy metals which increase cost, impede scalability, and add complexity. Therefore, the development of efficient, stable, economically feasible, and environmentally friendly catalysts is required. For many years carbon nitrides (CxNyHz) were famed for their structural variety and potential as precursors for ultra-hard materials. The thermal condensation of simple carbon nitrides (CNs) can form several denser chemical species that differ with respect to their degree of condensation, hydrogen content, crystallinity and morphology. The discovery of extended carbon nitrides with semiconducting properties and band gaps < 3 eV makes them an attractive alternative to metal-rich semiconductors for photocatalysis. In 2009, Wang et al. investigated and determined for the first time the photocatalytic activity of polymeric melon-type CNs based on imide-bridged heptazine units (Fig. 1a).[1] Further publications focused on the modifications of those heptazine based carbon nitrides to improve their photocatalytic activity, e.g. by expanding their surface area, as well as by doping with heteroatoms and organic compounds, which gives rise to an enhanced absorption in the visible light range of the electromagnetic spectrum.
    [Show full text]
  • Heptazine Imide Salts Can Exchange Metal Cations in the Solid State
    MPIKG Public Access Author Manuscript Published in final edited form as: Savateev, A., Pronkin, S., Willinger, M. G., Antonietti, M., & Dontsova, D. (2017). Towards Organic Zeolites and Inclusion Catalysts: Heptazine Imide Salts Can Exchange Metal Cations in the Solid State. Chemistry – An Asian Journal, 12(13), 1517-1522. doi:10.1002/asia.201700209. Towards organic zeolites and inclusion catalysts: heptazine imide salts can exchange metal cations in the solid state Savateev, A., Pronkin, S., Willinger, M. G., Antonietti, M., & Dontsova, D. Worth its salt: A variety of heptazine imide salts and a free base can be easily prepared by a simple ion exchange starting from the synthesized potassium derivative. Thus, various mono- and bivalent cations can be incorporated in the structure that resembles the behavior of zeolites. The photocatalytic activity in visible-light-driven hydrogen evolution is shown to depend on the nature of the introduced cation and reaches its maximum in the case of the Mg-salt. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving. Towards organic zeolites and inclusion catalysts: heptazine ipt imide salts can exchange metal cations in the solid state Aleksandr Savateev1, Sergey Pronkin2, Marc Willinger1,3, Markus Antonietti1, and Dariya Manuscr 1* Dontsova Abstract. Highly crystalline potassium (heptazine imides) were preparations. In addition, intercalation of chloride and prepared by the thermal condensation of substituted 1,2,4- · Author · bromide changes the gallery heights of the graphitic triazoles in eutectic salt melts. These semiconducting salts are already known to be highly active photocatalysts, e.g.
    [Show full text]
  • Composite Salt of Polyphosphoric Acid with Melamine, Melam, and Melem and Process for Producing the Same
    Europäisches Patentamt (19) European Patent Office Office européen des brevets (11) EP 0 990 652 A1 (12) EUROPEAN PATENT APPLICATION published in accordance with Art. 158(3) EPC (43) Date of publication: (51) Int. Cl.7: C07D 251/54, C09K 21/12, 05.04.2000 Bulletin 2000/14 C08K 5/51 (21) Application number: 98905654.4 (86) International application number: (22) Date of filing: 26.02.1998 PCT/JP98/00777 (87) International publication number: WO 98/39306 (11.09.1998 Gazette 1998/36) (84) Designated Contracting States: • SHINDO, Masuo, AT BE CH DE ES FR GB IT LI NL SE Nissan Chemical Industries Ltd Nei-gun, Toyama 939-2792 (JP) (30) Priority: 04.03.1997 JP 4921197 • IIJIMA, Motoko, Nissan Chemical Industries, Ltd (71) Applicant: Funabashi-shi, Chiba 274-8507 (JP) Nissan Chemical Industries, Ltd. Chiyoda-ku, Tokyo 101-0054 (JP) (74) Representative: Hartz, Nikolai F., Dr. et al (72) Inventors: Wächtershäuser & Hartz, • SUZUKI, Keitaro, Patentanwälte, Nissan Chemical Industries, Ltd Tal 29 Funabashi-shi, Chiba 274-8507 (JP) 80331 München (DE) (54) COMPOSITE SALT OF POLYPHOSPHORIC ACID WITH MELAMINE, MELAM, AND MELEM AND PROCESS FOR PRODUCING THE SAME (57) A melaminegmelamgmelem double salt of a polyphosphoric acid, which has a solubility of from 0.01 to 0.10 g/100 ml in water (25°C), a pH of from 4.0 to 7.0 as a 10 wt% aqueous slurry (25°C), and a melamine content of from 0.05 to 1.00 mol, a melam content of from 0.30 to 0.60 mol and a melem content of from 0.05 to 0.80 mol, per mol of the phosphorous atom; and A process for producing the above mentioned mela- minegmelamgmelem double salt of a polyphosphoric acid, which comprises the following steps (a) and (b): (a) a step of obtaining a reaction product by mixing melamine and phosphoric acid at a temperature of from 0 to 330°C in such a ratio that the melamine is from 2.0 to 4.0 mols per mol of the phosphoric acid (as calculated as orthophosphoric acid content), and (b) a step of baking the reaction product obtained in step (a) at a temperature of from 340 to 450°C for from 0.1 to 30 hours.
    [Show full text]