Phenanthrene

8 Key excerpts on "Phenanthrene"

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  Fundamentals of Sustainable Chemical Science

  • Stanley E. Manahan(Author)
  • 2009(Publication Date)
  • CRC Press

    (Publisher)

  As shown in Figure 9.8, some arenes, such as naphthalene and the polycyclic aromatic compound benzo[ and the polycyclic aromatic compound benzo[ a ]pyrene, contain fused rings. ]pyrene, contain fused rings. OH OH Cl 1 2 3 4 5 6 Naphthalene Phenol No H atoms 1 H atom Ortho Para Meta Benzo(a)pyrene 3-Chlorophenol or meta -chlorophenol Figure 9.8. Figure 9.8. Aromatic compounds containing fused rings (top) and showing the numbering of Aromatic compounds containing fused rings (top) and showing the numbering of carbon atoms for purposes of nomenclature. carbon atoms for purposes of nomenclature. 318 Fundamentals of Sustainable Chemical Science 318 Fundamentals of Sustainable Chemical Science Benzene and Naphthalene Benzene and Naphthalene Benzene is a volatile, colorless, highly flammable liquid used to manufacture Benzene is a volatile, colorless, highly flammable liquid used to manufacture phenolic and polyester resins, polystyrene plastics, alkylbenzene surfactants, chloro-phenolic and polyester resins, polystyrene plastics, alkylbenzene surfactants, chloro-benzenes, insecticides, and dyes. It is hazardous both for its ignitability and for benzenes, insecticides, and dyes. It is hazardous both for its ignitability and for its toxicity (exposure to benzene causes blood abnormalities that may develop into its toxicity (exposure to benzene causes blood abnormalities that may develop into leukemia). Naphthalene is the simplest member of a large number of polycyclic aro-leukemia). Naphthalene is the simplest member of a large number of polycyclic aro-matic hydrocarbons having two or more fused rings. It is a volatile white crystalline matic hydrocarbons having two or more fused rings. It is a volatile white crystalline solid with a characteristic odor and has been used to make mothballs. The most solid with a characteristic odor and has been used to make mothballs.

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  Conjugated Objects

  Developments, Synthesis, and Applications

  • Atsushi Nagai, Koji Takagi, Atsushi Nagai, Koji Takagi(Authors)
  • 2017(Publication Date)
  • Jenny Stanford Publishing

    (Publisher)

  2.1). The fusion of three benzene rings gives two isomers, depending on their connectivity. One is anthracene, which consists of three ortho -fused benzene rings in a linear arrangement. Another is Phenanthrene, in which naphthalene is fused with a benzene ring at the C1-C2 bond to form a bent structure. Further annelation of benzene ring(s) to anthracene in a linear manner gives the so-called [ n jacenes such as tetracene and pentacene. A zigzag annelation of benzene ring(s) to Phenanthrene affords [ n jphenacenes such as chrysene and picene. These [ n jacenes and [ n jphenacenes possess planar structures and demonstrate promising properties as organic semiconductors for OFETs. On the other hand, an angular annelation of benzene ring(s) to Phenanthrene gives [ n jhelicenes with nonplanar helical structures. [ n jHelicenes composed of six or more benzene rings exhibit stable helical chirality because of an intramolecular steric repulsion, which endows them with unique chiroptical properties. Heteroaromatic rings are also important modules for fused π-conjugated compounds since the introduction of heteroatom(s) into a π-conjugated framework is an effective way to control the electronic structure of them. In particular, thiophene-fused compounds have been well-studied in terms of synthesis and application as organic functional materials. For example, a series of thiophene-fused pentacyclic aromatic compounds were synthesized and found to demonstrate high semiconducting properties. Representative examples are shown in Fig. 2.2. In these compounds, benzene and/or thiophene rings are annelated in a linear fashion. Accordingly, these compounds are called as thienoacenes. Anthra[2,3- h :6,7- h ’]dithiophene (1) is apparently isoelectronic with pentacene, the corresponding pentacyclic hydrocarbon acene. However, compounds 2 and 3 should be considered not as [ n ]acenes but as [ n ]phenacenes in the sense of electronic structure

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  Air Pollution

  Health and Environmental Impacts

  • Bhola R. Gurjar, Luisa T. Molina, C.S. P. Ojha(Authors)
  • 2010(Publication Date)
  • CRC Press

    (Publisher)

  They are semivolatile compounds present in the atmosphere in both the vapor phase and the particulate phase as well as dissolved or suspended in precipitation. Most of the more potent carcinogens in this group have more than three rings, hence the name PAHs (or polynuclear aromatic hydrocarbons). 8.1.1 S TRUCTURE AND P ROPERTIES PAHs consist of two or more fused benzene rings in linear, angular, or cluster arrangements such as naphthalene, acenaphthene, anthracene, pyrene, chrysene, and benzo(a)pyrene (BaP) that are called alternant PAHs. They may also be composed of unsaturated four-, five-, and six-membered rings, referred to as nonalternant PAHs (Bostrom et al., 2002). The basic structural units are Phenanthrene, anthracene, and pyrene. Fusion of a benzene ring to face “a” of anthracene and pyrene gives rise to the most widely studied benz(a)anthracene and benz(a)pyrene. These compounds exist in many structural forms and also have a large number of isomers. The structures of PAHs and their structural interrelationships are depicted in Figure 8.1. The properties of PAHs are correlated to the number of rings, while minor differ-ences within each ring homologue can be attributed to the arrangement of rings. Table 8.1 lists the physical properties of PAH compounds commonly found in urban environmental samples. The general characteristics common to the class are high melting and boiling points and low vapor pressures. PAHs are sparingly soluble or practically insoluble in water. The solubility of BaP, for example, in water is of the Polycyclic Aromatic Hydrocarbons 231 order of 10 –8 to 10 –7 mol/L; surfactants such as detergents can substantially increase its solubility by formation of micelles. PAHs are soluble in many organic solvents: benzene, acetone, hexane, and tetrahydrofuran readily dissolve PAHs. They are also lipophilic; the lipophilicity increases with increasing complexity.

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  Synthesis of Aromatic Compounds

  • Kenneth E. Maly, Kenneth Maly(Authors)
  • 2022(Publication Date)
  • De Gruyter

    (Publisher)

  9  Fused aromatic rings – polycyclic aromatic hydrocarbons

  9.1  Introduction to polycyclic aromatic hydrocarbons

  Polycyclic aromatic hydrocarbons (PAHs) are a diverse class of organic molecules. They are found in fossil fuels such as crude oil, coal, and oil shale, and are also produced during incomplete combustion. PAHs also present environmental concerns and are known to be carcinogenic.

  The historical motivations for the synthesis of PAHs include the production of quinone dyes, fundamental studies on the nature of aromaticity, and to further understand the carcinogenic properties of these compounds. More recently, a renewed interest in the synthesis of PAHs stems from their potential utility as organic semiconductors or light-emitting materials. By virtue of molecular properties such as a low HOMO–LUMO gap and the ability to interact via π-stacking interactions, these compounds can often transport charge, thereby serving as a potential alternative to inorganic semiconductors. As such, there is a considerable effort to develop new synthetic methods for the preparation of PAHs. In this chapter, we will explore some of the general features of PAHs, including reactivity and stability. We will also explore some of the general approaches for the synthesis of PAHs, which will form the basis for the synthetic applications discussed in Chapters 10 and 11. For a more detailed discussion of the synthesis and reactivity of PAHs, Clar and Harvey each have books focused entirely on the synthesis of PAHs [1 , 2 ].

  9.1.1  Classification and nomenclature of PAHs

  PAHs are often classified based on how the rings are fused as cata-condensed systems, or as peri-condensed systems. Cata-condensed systems have ring fusions that only share two carbons (Figure 9.1 ). Peri-condensed systems have carbon atoms that serve as the fusion point for three rings (Figure 9.2 ).

  Figure 9.1:

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  Handbook of Water Analysis

  • Leo M.L. Nollet, Leen S. P. De Gelder, Leo M.L. Nollet, Leen S. P. De Gelder(Authors)
  • 2013(Publication Date)
  • CRC Press

    (Publisher)

  In addition, benzo[ c ]Phenanthrene and fluoro-anthene were suspected of being carcinogenic. The carcinogenicity of acenaphthene, acenaphthylene, benzo[ ghi ]fluoranthene, benzo[ a ]fluorene, benzo[ b ]fluorene, benzo[ e ]pyrene, coronene, naphthalene, Phenanthrene, and pyrene was considered questionable. Of these, naphthalene was considered to be noncarcinogenic due to its negative genotoxicity; the others were further evaluated. In its final evalua-tion, the IPCS found that next to naphthalene, anthracene, benzo[ ghi ]fluoranthene, benzo[ ghi ]perylene, fluorene, 1-methylPhenanthrene, perylene, and triphenylene should be considered noncarcinogenic [18]. The biological activities of a given PAH depends a lot on its structure. The PAHs have a wide variety of structures and these structural differences have a great effect on their reactivity and hence their bio-logical action. The ability of the compound to bind to the DNA molecule is directly proportional to its carcinogenicity [26]. The chemical structure plays a very important role in the binding of a given PAH to the aromatic hydrocarbon receptor (AhR). This is a helix–loop–helix transcription factor that is a member of the Per–Arnt–Sim family of transcription factors. PAHs with Phenanthrene structure fused to at least one benzo ring have been found to have the strongest DNA binding effect. The compounds that fall into this category can be divided into two classes, namely, those that possess a bay region and those that possess a fjord region. A good example of a PAH with a bay region is benzo[ a ]pyrene as shown in Figure 28.1, and a good example of fjord (or hindered bay) region compound is dibenzo[ a , l ]pyrene as shown in Figure 28.3. The bay region and the fjord region are the two structural attributes that effect positively the bind-ing of PAHs to the DNA and consequently increases the carcinogenicity of a given compound.

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  Food Contaminants and Residue Analysis

  • Yolanda Picó(Author)
  • 2008(Publication Date)
  • Elsevier Science

    (Publisher)

  Polycyclic aromatic hydrocarbons (PAHs) are a large class of well-known carcinogenic compounds. These compounds are mainly formed by pyrolytic processes, especially the incomplete combustion of organic matter through natural and anthropogenic processes, such as forest fires, processing of coal and crude oil, vehicle traffic, residential heating, industrial power generating, cooking, smoking and so on. Some PAHs are commercially used as intermediates in industrial manufacturing. Naphthalene (Naph), anthracene (An) and Phenanthrene (Phe) are used as raw materials in the production of dye, celluloid, lubricants, fibres, plastics and insecticides. However, the amounts of PAHs for commercial use are much less than those generated by incomplete combustion.

  Owing to their widespread distribution in the environment, PAHs have been detected in air [1 –5] , sediment [6 –9] , soil [10 –15] , indoor air [16 –18] and daily diet [19 –24] and almost everywhere in the environment.

  PAHs contain two or more fused aromatic rings in their chemical structures, and have several hundred structural isomers. A number of PAHs and their related compounds have been detected in the environment. Among them, PAHs containing 24 or fewer ring carbon atoms (e.g., benz[a ]anthracene, B[a ]A; benzo[a ]pyrene, B[a ]P; dibenzo[ah ]pyrene, DB[ah ]P) have been chosen as target compounds for environmental monitoring owing to their biological effects. As a number of PAHs have proved to be mutagenic and/or carcinogenic and are considered to be major potential causes of cancer in humans, the occurrence of PAHs in the environment is of concern for public health in general.

  The fact that cancer could be due to exogenous causes was brought to light in 1775 by Sir Percival Pott [25] . He found that scrotal cancer in his patients, chimneysweepers, might be induced by professional exposure to soot and tar. The first experimental proof in animals to support this clinical impression was achieved by Yamagiwa and Ichikawa [26] in 1915. They succeeded in inducing neoplastic changes by patient application of coal tar to the ears of rabbits. The fact that pure chemical compounds might induce cancer in mammals was first demonstrated by Kennaway in 1930 [27] , in seeking of carcinogens in high-boiling fractions of coal tar distillates. A few years later, Cook et al. [28] identified B[a

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  New Frontiers in Nanochemistry: Concepts, Theories, and Trends

  Volume 3: Sustainable Nanochemistry

  • Mihai V. Putz, Mihai V. Putz, Mihai Putz(Authors)
  • 2020(Publication Date)
  • Apple Academic Press

    (Publisher)

  CHAPTER 21 Polycyclic Aromatic Hydrocarbons (PAHs) MARINA A. TUDORAN, 1, 2 ANA-MARIA PUTZ, 1, 3 LAURA PITULICE, 1 and MIHAI V. PUTZ 1, 2 1 Laboratory of Structural and Computational Physical Chemistry for Nanosciences and QSAR, Biology-Chemistry Department, West University of Timisoara, Pestalozzi Street No. 44, Timisoara, RO–300115, Romania 2 Laboratory of Renewable Energies-Photovoltaics, R&D National Institute for Electrochemistry and Condensed Matter, Dr. A. Paunescu Podeanu Str. No. 144, Timisoara, RO–300569, Romania 3 Institute of Chemistry Timisoara of the Romanian Academy, 24 Mihai Viteazul Bld., Timisoara 300223, Romania 21.1 DEFINITION Polycyclic aromatic hydrocarbons (PAHs) represent a class of organic compounds with three or more fused benzene rings containing only carbon and hydrogen, produced by incomplete combustion or high-pressure processes, i.e., when complex organic substances are exposed to high temperatures or pressures. 21.2 HISTORICAL ORIGIN(S) PAHs represent a class of organic compounds, having two or more bonded benzene rings in one of the three forms (Arey and Atkinson, 2003; Di-Toro et al., 2000): linear, angular or cluster arrangements (see Figure 21.1). They have an interesting characteristic: they bond with hydrogen atoms and forms aromatic rings similar to graphite (Putz et al., 2013). As a mechanism of formation, PAHs have different sources, such as products of incomplete combustion from man-made combustion sources, natural combustion sources or biological processes (Abdel-Shafy and Mansour, 2016). They are solid compounds, white, and pale yellow or colorless, with low vapor pressure and high boiling and melting points (Masih et al., 2012)

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  Handbook of Food Analysis

  Volume 2: Residues and Other Food Component Analysis

  • Leo M.L. Nollet(Author)
  • 2004(Publication Date)
  • CRC Press

    (Publisher)

  38 Polycyclic Aromatic Hydrocarbons in Food Katsumi Tamakawa Sendai City Institute of Public Health, Sendai, Japan I. INTRODUCTION Polycyclic aromatic hydrocarbons (PAHs) are organic compounds containing two or more fused aromatic rings of carbon and hydrogen atoms. They are ubi-quitous environmental pollutants and are a major class of environmental hazardous compounds due to their known or suspected carcinogenicity and/or mutagenicity. PAHs are generally produced by incom-plete combustion of material such as the burning of fossil fuels, and other forms of organic matter. They are also diffused into the environment through natural and anthropogenic processes and have been detected in air (1–6), water (7–10), soil (11–17), indoor air (18–20), work places (21–23), food, and elsewhere. Although it was suggested that PAHs could be synthesized biolog-ically from bacteria, plants, and seaweed as their metabolites, this origin is not fully accepted, yet (24). Some PAHs are commercially used as intermediates in production processes. That is, Phenanthrene (Phe) for pesticides, acenaphthene (Ace) and pyrene (Py) for pigments, anthracene (An) and flouranthene (Flu) for dyes, and naphthalene (Naph) for plasticizer pro-duction. Considering their amount used for produc-tion, PAHs detected in the environment are mainly a result of incomplete combustion rather than from com-mercial use. Primary anthropogenic sources of PAHs include: motor vehicle exhaust, products from petro-leum refineries, industrial machinery manufactures, coke production, anode baking for aluminum, envi-ronmental tobacco smoke, barbecue smoke, etc. (25). The emissions of benzo[ a ]pyrene (B[ a ]P) into the air in the Federal Republic of Germany were estimated to be 18 tonnes. About 30% was caused by coke production, and 58% by heating with coal (26).

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