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1
Laelasari, Eva, Dewi Kristanti, and Basuki Rahmat. "PENGGUNAAN LEM SEPATU DAN GANGGUAN KESEHATAN PEKERJA INDUSTRI SEPATU DI CIOMAS, BOGOR." JURNAL EKOLOGI KESEHATAN 17, no. 2 (October 16, 2018): 85–95. http://dx.doi.org/10.22435/jek.17.2.150.85-95.
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ABSTRACT
The use of glue in shoe manufactures may cause health impacts among workers due to hazardous chemical exposure in glue such as benzene and toluene. The government has issued policies to prevent the workers from occupational illness by reducing the hazardous chemical exposure in the workplace. This study was conducted to find out health impacts due to benzenae and toluene exposure from the use of glue in the workplace of shoe manufactures in Ciomas, Bogor in 2017. Design of the study was cross sectional with variables of benzene and toluene content in indoor workspace, consentration of urinary S-PMA, and perceived health symptoms of workers. Samples of 34 respondents were obtained from 5 selected workshop. Analysis of the data was carried out descriptively. It was found that the content of benzene and toluene in glue are 0.1% and 55% respectively, indoor benzene vapor was below detection limit of the instrument (undetected), and concentration of urinary S-PMA was 0.24 µg/g creatinine. There was no benzene exposure to the workers in this study. High percentage of worker risk behavior were smoking, the use of PPE, and hand washing. Perceived symptoms of workers (more than 60%) were fatigue, headache, tingling. It is necessary to improve workplace with healthier and more conducive environment, and educate workers to use the PPE.
Keywords: Shoe glue, benzene, toluene, exposure, small scale shoe manufacture
ABSTRAK
Penggunaan lem pada industri sepatu kemungkinan memberikan dampak kesehatan terhadap pekerja karena lem biasanya mengandung bahan berbahaya, seperti benzena dan toluena. Pemerintah sudah berupaya membuat kebijakan untuk mengendalikan penyakit akibat kerja, salah satunya adalah mengurangi pajanan bahan kimia berbahaya. Penelitian ini bertujuan untuk mengetahui dampak kesehatan akibat pajanan benzena dan toluena yang berasal dari penggunaan lem di tempat kerja di sentra industri sepatu Ciomas, Bogor pada tahun 2017. Desain penelitian adalah potong lintang dengan variabel kandungan benzena dan toluena di udara ruang kerja, kandungan S-PMA dalam urin, dan gangguan kesehatan yang dialami oleh pekerja. Jumlah sampel pekerja sebanyak 34 orang yang berasal dari 5 bengkel kerja. Analisis data dilakukan secara deskriptif. Hasil penelitian menunjukkan bahwa kadar benzena dan toluena dalam lem masing-masing adalah 0,1% dan 55%, kadar uap benzena di udara ruang kerja berada di bawah limit deteksi alat (tidak terdeteksi), dan rerata kandungan S-PMA dalam urin adalah 0,24 µg/g kreatinin. Tidak terjadi pajanan benzena terhadap pekerja industri sepatu di lokasi penelitian. Perilaku berisiko pekerja dengan persentase cukup tinggi adalah merokok, penggunaan APD, dan cuci tangan. Keluhan/gangguan kesehatan yang dirasakan (lebih dari 60%) adalah cepat lelah, sakit kepala, kesemutan. Perlu perbaikan lingkungan kerja yang lebih sehat dan nyaman, dan mengedukasi pekerja untuk menggunakan APD.
Kata kunci: Lem sepatu, benzena, toluena, pajanan, industri sepatu rumahan
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HUFF, J. E., W. EASTIN, J. ROYCROFT, S. L. EUSTIS, and J. K. HASEMAN. "Carcinogenesis Studies of Benzene, Methyl Benzene, and Dimethyl Benzenes." Annals of the New York Academy of Sciences 534, no. 1 Living in a C (June 1988): 427–40. http://dx.doi.org/10.1111/j.1749-6632.1988.tb30132.x.
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Maraval, Valérie, Remi Chauvin, Kévin Cocq, Cécile Barthes, and Arnaud Rives. "Synthesis of Functional Carbo-benzenes with Functional Properties: The C2 Tether Key." Synlett 30, no. 01 (October 12, 2018): 30–43. http://dx.doi.org/10.1055/s-0037-1610269.
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Beyond demonstration of conceptual relevance and synthetic feasibility of aryl/alkyl-substituted representatives, carbo-benzene molecules started to gain prospects of broader impact through the emergence of alkynyl derivatives. This is first illustrated by examples of di- and hexaalkynyl-carbo-benzenes, a carbo-naphthalene, a carbo-biphenyl, and two carbo-terphenyls. A focus is then given to dialkynyl derivatives by reference to the peripherally C2-extruded parents. In the centrosymmetric quadrupolar series, the C2 expansion or ethynylogation effect is more particularly considered for 9H-fluoren-2-yl, tris(O-n-alkyl)pyrogallyl, indol-3-yl, 4-anilinyl, and tetraphenyl-carbo-phenyl substituents on the following respective properties: two-photon absorption, chemical stability, columnar mesogenicity, on-surface photoinduced charge separation vs single-molecule conductance, and reduction potential. Topical results and prospects of application are discussed on the basis of crystallographic, spectroscopic, and electrochemical analyses vs DFT-calculated nuclear and electronic structures. For the sake of the discussion consistency, complementary experimental and computational results are disclosed in the dianilinyl series. Overall, it is shown that combined advances in strategy, protocols, and substrate scope of acetylenic synthesis remain crucial for the development of yet poorly explored but promising types of molecular materials.1 Introduction2 Hexaalkynyl-carbo-benzene3 ortho-Dialkynyl-carbo-benzene4 para-Dialkynyl-carbo-benzenes4.1 Bistrimethylsilylethynyl-carbo-benzene4.2 Bisfluorenylethynyl-carbo-benzene4.3 Bistrialkoxyarylethynyl-carbo-benzenes4.4 Bisindolylethynyl-carbo-benzene4.5 Bisanilinylethynyl-carbo-benzene5 Carbo-oligo(phenyleneethynylene)s6 Conclusions
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Li, Jiayue. "Overview of benzene and exploration of benzene structure." Theoretical and Natural Science 21, no. 1 (December 20, 2023): 245–52. http://dx.doi.org/10.54254/2753-8818/21/20230889.
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Benzene is a hydrocarbon the simplest aromatics. But the search for benzenes structure has been tortuous. This article mainly introduces the basic properties of benzene. From the physical properties of benzene to the chemical properties of benzene to the uses of benzene. In this work, we also summarize the process of scientists exploration of benzene structure and introduce the background of benzene. Of all the structures of benzene, the Kekule structure is the most recognized structure. We have proved the correctness of the Kekule structure by the product of the ozonation decomposition reaction of o-xylene. However, the Kekule structure has some limitations, the search for benzene structure is still ongoing, and we are still trying to find ways to better describe the structure of benzene. So we also sum up some modern theories about the structure of benzene. In addition, benzene is a very common chemical raw material. The article also lists some chemical products made from benzene.
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Holle, Rizky B., Audy D. Wuntu, and Meiske S. Sangi. "Kinetika Adsorpsi Gas Benzena Pada Karbon Aktif Tempurung Kelapa." Jurnal MIPA 2, no. 2 (July 8, 2013): 100. http://dx.doi.org/10.35799/jm.2.2.2013.2997.
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Telah diteliti kinetika adsorpsi gas benzena pada karbon aktif tempurung kelapa yang diaktivasi dengan NaCl dengan tujuan menentukan model kinetika yang dapat diaplikasikan untuk adsorpsi gas benzena pada karbon aktif tempurung kelapa. Data adsorpsi dianalisis dengan menggunakan empat model persamaan laju adsorpsi yaitu (1) persamaan laju order pertama pseudo Lagergren, (2) persamaan laju order kedua pseudo Ho, (3) persamaan Elovich, dan (4) persamaan Ritchie. Hasil kajian menunjukkan bahwa model kinetika dengan persamaan laju order ke-2 pseudo Ho adalah yang paling sesuai diaplikasikan untuk adsorpsi gas benzena pada karbon aktif tempurung kelapa. Dari model kinetika order ke-2 pseudo Ho diperoleh konstanta adsorpsi benzena sebesar 1,63x10-4 g mg-1 min-1. Nilai energi adsorpsi menunjukkan bahwa benzena teradsorpsi secara fisik pada adsorben.Kinetics of gaseous benzene adsorption on coconut shell NaCl-activated carbon had been studied. The research was aimed to determine the appropriate kinetic model applied to gaseous benzene adsorption on the adsorbent. Adsorption data was analyzed using four kinetic models of adsorption rate equation, which were (1) Lagergren’s pseudo first order rate equation, (2) Ho’s pseudo second order rate equation, (3) Elovich‘s equation, and (4) Ritchie’s equation. The results showed that the Ho’s pseudo second order rate equation was best applied to gaseous benzene adsorption on coconut shell activated carbon. The second order rate constant for benzene adsorption was 1.63x10-4 g mg-1 min-1. The value of adsorption energy showed that benzene was physically adsorbed on the adsorbent.
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Cao, Chuan-Wang, Fang Niu, Xiao-Peng Li, Shi-Lin Ge, and Zhi-Ying Wang. "Acute and joint toxicity of twelve substituted benzene compounds to Propsilocerus akamusi Tokunaga." Open Life Sciences 9, no. 5 (May 1, 2014): 550–58. http://dx.doi.org/10.2478/s11535-014-0289-y.
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AbstractThis study investigated the toxic effects of 12 substituted benzenes exposed to Propsilocerus akamusi larvae singly and as mixtures. Their toxicities were quantified in terms of median effective concentration (EC50) killing 50% of the larvae. For individual substituted benzenes to 4th-instar P. akamusi larvae, the toxicity was in decreasing order of p-chlorophenol > nitrobenzene > phenol > 1,2-dimethylbenzene > 1,3-dimethylbenzene > chlorobenzene > p-phenylenediamine > 1,4-dimethylbenzene > m-phenylenediamine > methylbenzene > benzene > aniline. The order of toxicity among three isomers of dimethylbenzene was 1,2-dimethylbenzene > 1,3-dimethylbenzene > 1,4-dimethylbenzene while p-phenylenediamine > m-phenylenediamine. The binary substituted benzene compounds’ toxicities were evaluated by toxic unit (TU), additive index (AI), mixture toxicity index (MTI) and similarity parameter index (λ). The evaluation results of TU and MTI for 9 substituted benzene compounds were completely consistent while the results of AI were the same as the results of λ based on 24 h EC50 of binary substituted benzenes. The evaluation results of 10 substituted benzene compounds were consistent using TU, MTI, AI and λ evaluation methods. 52.63% and 47.37% of binary substituted benzene tests on P. akamusi larvae showed synergism and partial addition/antagonism, respectively, under mixtures of equal proportions. These results suggest that substituted benzenes indicate acute and binary joint toxicity to P. akamusi.
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Ajenjo, Javier, Martin Greenhall, Camillo Zarantonello, and Petr Beier. "Synthesis and nucleophilic aromatic substitution of 3-fluoro-5-nitro-1-(pentafluorosulfanyl)benzene." Beilstein Journal of Organic Chemistry 12 (February 3, 2016): 192–97. http://dx.doi.org/10.3762/bjoc.12.21.
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3-Fluoro-5-nitro-1-(pentafluorosulfanyl)benzene was prepared by three different ways: as a byproduct of direct fluorination of 1,2-bis(3-nitrophenyl)disulfane, by direct fluorination of 4-nitro-1-(pentafluorosulfanyl)benzene, and by fluorodenitration of 3,5-dinitro-1-(pentafluorosulfanyl)benzene. The title compound was subjected to a nucleophilic aromatic substitution of the fluorine atom with oxygen, sulfur and nitrogen nucleophiles affording novel (pentafluorosulfanyl)benzenes with 3,5-disubstitution pattern. Vicarious nucleophilic substitution of the title compound with carbon, oxygen, and nitrogen nucleophiles provided 3-fluoro-5-nitro-1-(pentafluorosulfanyl)benzenes substituted in position four.
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Hocek, Michal, Irena G. Stará, Ivo Starý, and Hana Dvořáková. "Covalent Analogues of DNA Base-Pairs and Triplets IV. Synthesis of Trisubstituted Benzenes Bearing Purine and/or Pyrimidine Rings by Cyclotrimerization of 6-Ethynylpurines and/or 5-Ethynyl-1,3-dimethyluracil." Collection of Czechoslovak Chemical Communications 67, no. 8 (2002): 1223–35. http://dx.doi.org/10.1135/cccc20021223.
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Ni-Catalyzed cyclotrimerizations of 6-ethynylpurines 3 or 5-ethynyl-1,3-dimethyluracil (4) afforded the 1,2,4-tris(purin-6-yl)benzenes 7 or 1,2,4-tris(1,3-dimetyhyluracil-5-yl)benzene (9), respectively. The symmetrical 1,3,5-tris(purin-6-yl)benzenes 8 were also formed as minor products in very low yields. Co-cyclotrimerization of 9-benzyl-6-ethynylpurine (3a) with 4 afforded the tris(purinyl)benzene 7a as a major product along with 1,2-bis(9-benzylpurin-6-yl)-4-(1,3-dimethyluracil-5-yl)benzene (10) and a complex mixture of other derivatives and isomers. Compounds 7-10 are analogues of Hoogsteen base-triplets.
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Streitwieser, Andrew, and Erich R. Vorpagel. "Electron density analysis of substituent effects in substituted benzenes." Collection of Czechoslovak Chemical Communications 53, no. 9 (1988): 1961–80. http://dx.doi.org/10.1135/cccc19881961.
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Electron projection functions and the corresponding difference functions relative to benzene are computed for π and σ electronic systems of several substituted benzenes, fluorobenzene, toluene and anilinium cation, and idealized model substituents, benzene with an external point positive charge and benzene with an external dipole. The results are plotted and integrated difference populations are compared with Mulliken populations. The later give good agreement, especially for π-systems, but obscure the underlying polarization especially evident in σ systems.
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Aroney, MJ, E. Patsalides, and RK Pierens. "Malononitrile in Aromatic Solvents—Geometry of Solvation." Australian Journal of Chemistry 38, no. 3 (1985): 507. http://dx.doi.org/10.1071/ch9850507.
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Polarization and electric birefringence measurements are reported for malononitrile in dioxan , benzene and hexafluorobenzene solutions. These data, together with 1H n.m.r .shifts, are used to explore solute-solvent interactions. Changes in the proton shifts of CH2(CN)2 are studied with replacement of benzene solvent by fluorinated benzenes.
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Shu, Kunxian, Jie Zhao, Shuai Yuan, Yusheng Dou, and Glenn V. Lo. "Mechanisms of Laser-Induced Reactions of Stacked Benzene Molecules: A Semiclassical Dynamics Simulation and CASSCF Calculation." International Journal of Photoenergy 2014 (2014): 1–11. http://dx.doi.org/10.1155/2014/874102.
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The response to ultrashort laser pulses of two stacked benzene molecules has been studied by semiclassical dynamics simulation; two typical pathways were found following excitation of one of the benzene molecules by a 25 fs (FWHM), 4.7 eV photon. With a fluence of 40.49 J/m2, the stacked molecules form a cyclobutane benzene dimer; the formation of the two covalent bonds linking two benzenes occurs asynchronously after the excimer decays to electronic ground state. With a fluence of 43.26 J/m2, only one bond is formed, which breaks about 50 fs after formation, followed by separation into the two molecules. The deformation of benzene ring is found to play an important role in the bond cleavage.
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Stanger, Amnon. "Is (benzene)Cr(CO)3 really more aromatic than benzene?" Canadian Journal of Chemistry 95, no. 3 (March 2017): 263–70. http://dx.doi.org/10.1139/cjc-2016-0334.
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(benzene)Cr(CO)3 was claimed to be more aromatic than benzene, based on the central 1H Me chemical shifts in dimethyldihydropyrene annulated to it. In this paper, several dihydropyrenes are computationally investigated. NICS-scan methods are used to assess the ring current properties, and NMR calculations are used for obtaining NMR chemical shifts. The parent and four benz-annulated dihydropyrenes show excellent agreement with the experimental results, reported by R. Mitchell in several papers. The effect of annulating the antiaromatic cyclobutadiene was shown to be larger than that of benzene and to change the type of ring currents; while benz-annulated dihydropyrenes maintain local 14-annulene and local benzenic ring currents, the cyclobutadiene-annulated dihydropyrenes show global (and local) ring currents. A NICS-scan study of (benzene)Cr(CO)3 and a NICS-XY-scan study of the (CO)3Cr(C6H4)-annulated to dihydropyrene show that the benzene in the Cr complex is at most aromatic as benzene, probably somewhat less. A detailed study of the 1H chemical shifts suggests that the experimental results were somewhat misinterpreted, and that (benzene)Cr(CO)3 is at most as aromatic as benzene.
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Jones, Peter G., and Piotr Kuś. "Secondary Interactions in Bromomethyl-substituted Benzenes: Crystal Structures of Three α,α′-Bis-bromoxylenes, 1,2,3,5-Tetrakis(bromomethyl)benzene, and 1,2,4,5-Tetrakis(bromomethyl)benzene." Zeitschrift für Naturforschung B 62, no. 5 (May 1, 2007): 725–31. http://dx.doi.org/10.1515/znb-2007-0517.
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Abstract X-Ray structure determinations of all three isomers of bis(bromomethyl)benzene and of two isomeric tetrakis(bromomethyl)benzenes show that the packing of the molecules is determined principally by interactions of the bromomethyl groups (C-H· · ·Br and Br· · ·Br), except for ortho-bis (bromomethyl)benzene, in which C-H· · ·π interactions play a major role.
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ZUO, TIANMING, and THOMAS HUANG. "AN MMX STUDY OF BENZENE ISOMERS AND THE HYDROGENATION PRODUCTS OF BENZENE." Journal of Theoretical and Computational Chemistry 03, no. 01 (March 2004): 23–30. http://dx.doi.org/10.1142/s0219633604000830.
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We have calculated the structures, the heats of hydrogenation and the resonance energies of benzene isomers. All structures and energies were calculated by using the MMX force fields. Using PC model, the calculated structure parameters of benzene's 8 isomers are generally in good agreements with the experimental data. The heats of hydrogenation and resonance energy of benzene isomers are parallel to those experimental data and need a systematic adjustment of 4.5 kJ/mol.
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Ali, Md Eaqub, Md Motiar Rahman, and Sharifah Bee Abd Hamid. "Nanoclustered Gold: A Promising Green Catalysts for the Oxidation of Alkyl Substituted Benzenes." Advanced Materials Research 925 (April 2014): 38–42. http://dx.doi.org/10.4028/www.scientific.net/amr.925.38.
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Catalytic oxidation of alkyl substituted benzenes is an essential route for the synthesis of a number of important chemicals, perfumes, drugs and pharmaceuticals. The oxidation products of ethyl benzene are important precursors for a wide range of pharmaceuticals and synthetic materials. Acetophenone and 1-phenylethanol are two oxidation products of ethyl benzene which are the precursors of optically active alcohol, benzalacetophanones, hydrazones and so on. However, the oxidations of alkyl substituted benzenes have been remaining a challenging task. This is because of the limitations of an appropriate catalyst and requirement of corrosive chemical treatments (potassium permanganate/dichromate and ammonium cerium nitrate) which are hazardous and environmentally unfriendly. The current industrial practice in the oxidation of ethyl benzene unfortunately involves high temperature thermal autoxidation in the absence of catalysts. Although few catalysts have been tested for the oxidation of ethyl benzene, many of them found to be inefficient. For example, cobalt (II) oxide-immobilized on mesoporous silica (Co/SBA-15) was used to catalyze oxidation of alkyl benzene at high temperature (125-150°C) but only 70% conversion was obtained after prolong treatment at 150°C. Additionally, the catalyst formed mixed uncontrolled oxidation products like 1-phenylethyl hydro peroxide, benzoic acid, acetophenone and phenyl ethanol. Carbon/silica/metal oxide supported nanoporous gold is a promising green catalyst for heterogenous molecular transformation. This is because of their three dimensional open pore network structures, high surface to volume ratio, high reusability, distinct optolectronic and physio-chemical properties. Mesoporous carbon/silica/metal oxide thin film supports provide increase dispersion of metal nanocatalysts and facilitate transport of molecules, ions or electrons through the nanopores/nanochannels, enhancing product yields with minimum cost and time. This paper has reviewed various gold-skeleton green catalysts and their preparation and mechanistic schemes for the selective oxidation of alkyl substituted benzenes.
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Ikeda, Toshiaki, Tetsuya Masuda, Midori Takayama, Hiroaki Adachi, and Takeharu Haino. "Solvent-induced emission of organogels based on tris(phenylisoxazolyl)benzene." Organic & Biomolecular Chemistry 14, no. 1 (2016): 36–39. http://dx.doi.org/10.1039/c5ob01898f.
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Schmidt, Lisa, Danny Wagner, Martin Nieger, and Stefan Bräse. "Functionalized C3-Symmetric Building Blocks—The Chemistry of Triaminotrimesic Acid." Molecules 27, no. 14 (July 7, 2022): 4369. http://dx.doi.org/10.3390/molecules27144369.
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A series of C3-symmetric fully substituted benzenes were prepared based on alkyl triamino-benzene-tricarboxylates. Starting with a one step-synthesis, the alkyl triamino-benzene-tricarboxylates were synthesized using the corresponding cyanoacetates. The reactivity of these electronically sophisticated compounds was investigated by the formation of azides, the click reaction of the azides and a Sandmeyer-like reaction. Caused by the low stability of triaminobenzenes, direct N-alkylation was rarely reported. The use of the stable alkyl triamino-benzene-tricarboxylates allowed us total N-alkylation under standard alkylation conditions. The molecular structures of the C3-symmetric structures have been corroborated by an X-ray analysis.
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Hartshorn, CM, and PJ Steel. "Poly(pyrazol-1-ylmethyl)Benzenes: New Multidentate Ligands." Australian Journal of Chemistry 48, no. 9 (1995): 1587. http://dx.doi.org/10.1071/ch9951587.
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Twelve new multidentate poly(pyrazol-1-ylmethyl)benzene ligands , (5)-(16), have been synthesized by phase-transfer-catalysed alkylations of pyrazoles with poly( bromomethyl )benzenes, and their 1H and 13C n.m.r. spectra have been fully assigned. X-Ray crystal structure determinations have been carried out on the tetrachloropalladate salt of the diprotonated form of 1,4-bis(3,5-dimethylpyrazol-1-ylmethyl)-2,3,5,6-tetramethylbenzene and on hexakis (pyrazol-1-ylmethyl)benzene.
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Tualeka, Abdul Rohim, Mohd Yusmaidie Aziz, Velu Perumal, Tamilanban Thamaraikani, Roslan Rosnon, Salsabila Novianti, Pudji Rahmawati, and Ahsan Ahsan. "Relationship between benzene concentration, MDA levels and kidney function in car painting workshops in Surabaya: A cross-sectional observational study." F1000Research 12 (June 5, 2024): 1419. http://dx.doi.org/10.12688/f1000research.140287.2.
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Background Car painting workers are at risk because of the use of solvents containing benzene as the main ingredient in the car painting process. One of the clinical effects of systemic benzene is kidney disorders. Therefore, the purpose of this study is to analyze the relationship between benzene and Risk Quotient (RQ) benzene concentrations with Malondialdehyde (MDA), Blood Urea Nitrogen (BUN), and creatinine levels in workers exposed to benzene in car painting workshops in Surabaya. Methods This study used an observational design with a cross-sectional method conducted at two car paint workshops in Surabaya. The study population was all workers exposed to benzene in the two car paint workshops, aged between 20-65 years in 2019. The sample was taken using an accidental sampling method, involving 30 respondents. Inclusion criteria included workers exposed to benzene and willing to participate, while exclusion criteria included workers with a liver or kidney disease history. The variables studied included benzene concentration, benzene RQ (benzene metabolite), malondialdehyde (MDA) levels as a marker of oxidative stress, and indicators of kidney function (BUN and creatinine levels). Data were analyzed using descriptive and bivariate analysis with Pearson correlation test. Results There was no significant relationship between concentrations, RQ benzene, and MDA levels in workers in painting in Surabaya (p> 0.05). There was no significant relationship between benzene concentration, BUN levels, and creatinine levels in paint workers in Surabaya (p> 0.05). There was no significant relationship between benzene RQ and BUN and creatinine levels in paint workers in Surabaya (p> 0.05). Conclusions This study's results indicate that benzene's effects do not lead to impaired kidney function. The benzene RQ variable in this study did not become a determining factor in BUN and creatinine levels in workers.
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Iakobson, George, Junyi Du, Alexandra M. Z. Slawin, and Petr Beier. "Pyridine-promoted dediazoniation of aryldiazonium tetrafluoroborates: Application to the synthesis of SF5-substituted phenylboronic esters and iodobenzenes." Beilstein Journal of Organic Chemistry 11 (August 26, 2015): 1494–502. http://dx.doi.org/10.3762/bjoc.11.162.
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Pyridine promotes dediazoniation of aryldiazonium tetrafluoroborates. The formed aryl radicals were trapped with B2pin2, iodine, or tetrahydrofuran to afford boronic esters, iodobenzenes and benzenes, respectively. The application to the synthesis of (pentafluorosulfanyl)phenylboronic esters, iodo(pentafluorosulfanyl)benzenes and (pentafluorosulfanyl)benzene is shown.
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Nguyen Nhu, Thuong, Thuy Le Thi, Phuong Thao Nguyen Thi, Binh Vu Ngan, Anh Huong Nguyen Thi, Son Tran Cao, and Trang Vu Thi. "Development of GC-MS for determination of benzene content in food products containing benzoate salts and ascorbic acid." Heavy metals and arsenic concentrations in water, agricultural soil, and rice in Ngan Son district, Bac Kan province, Vietnam 5, no. 3 (October 2, 2022): 422–32. http://dx.doi.org/10.47866/2615-9252/vjfc.3961.
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Food products containing simultaneously benzoate salts and ascorbic acid have a risk of benzene formation. This study has developed gas chromatography-mass spectrometry method GC-MS to determine the benzene content in foods containing benzoate salts and ascorbic acid simultaneously. The analyte sample was distilled to recover benzene and analyzed on GC-MS using a purge and trap injector, the analysis was controlled by benzened6 internal standard. The method has been validated for the parameters specified by AOAC. The method detection limit was 0.05 µg/kg, the method quantification limit was 0.15 µg/kg, the recovery ranged from 86.6 to 110.9%, Repeatability, RSDr in the range of 4.0 - 7.2%. The method has been applied to analyze the benzene content in 120 food samples including: soft drinks, fruit nectar, chili sauce and jam. Results of detecting benzene in 33 samples out of 120 surveyed samples, benzene content ranged from 0 to 109.7 µg/kg.
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Li, Bo, Yangqiu Li, Shaohua Chen, Lijian Yang, Wei Yu, Weiwei Liu, and Jiayu Chen. "CD3-Zeta Gene Expression in Workers Benzene-Exposed and Benzene- Poisoned Workers." Blood 112, no. 11 (November 16, 2008): 4925. http://dx.doi.org/10.1182/blood.v112.11.4925.4925.
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Abstract Benzene is an industrial chemical and component of cigarette smoke, gasoline, and automobile emissions. Benzene’s toxic effects on the blood and bone marrow can induce aplastic anemia and leukemia. Benzene is known to be highly toxic to a variety of cell types including lymphocytes. Our previous study showed that skewed distribution and clonal expansion of TCR Vα subfamily T cells had been found in benzene-exposed workers, indicating that the disorder of T cell immune function might relate to benzene-exposed. The TCR expressed on the surface of T cells is associated with an invariant structure-CD3 and composed the TCR/CD3 complex. The CD3ζ chain plays an important role in the complex which involved in signal transduction. Little is known about the feature of CD3 ζ chain expression in benzene-exposed workers. To further identify the expression level of CD3 ζ gene in benzene-exposed workers, real-time PCR with SYBR Green±technique was used for detecting CD3 ζ gene expression level in peripheral blood mononuclear cells from 29 benzene-exposed workers, 42 benzene-poisoned workers and 20 normal individuals. β2- microglobulin gene (β2M) was used as an endogenous reference. Relative changes in CD3 ζ gene expression level was used by the 2−ΔCt×100% method (ΔCt=Ct(ζ) −Ct(β2M) ). CD3ζ gene could be detected in all of normal individuals, however, only 21 out of 29 benzeneexposed workers could be detected the CD3ζ gene with a mean expression level of 15.0 ±24.9, and in 33 of all 45 benzene-poisoned workers with mean value of 19.8 ±29.7. The detectable CD3 ζ gene expression level in both benzene-exposed and benzene-poisoned groups increased significantly compared with that in normal individuals (3.00±2.11, P< 0.05). This is, to our knowledge, the first description of the effect of benzene-exposed on the expression of the CD3 ζ gene. The abnormality expression of CD3 ζ gene might lead to immune dysfunction in benzene-exposed and benzene-poisoned workers. In addition, CD3ζ gene could not be detected in a part of samples, whether the absence of CD3ζ gene might related to dysfunction of T cells in workers with benzene-exposed and benzenepoisoned, it remains an open question.
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Takriti, Salaheddin. "Radiation-Induced Degradation and the Effect of Scavengers on Benzene, Monochlorobenzene and 1,2-Dichlorobenzene in Aqueous Solutions." Water Quality Research Journal 39, no. 3 (August 1, 2004): 245–51. http://dx.doi.org/10.2166/wqrj.2004.034.
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Abstract The degradation of benzene, monochlorobenzene and 1,2-dichlorobenzene in aqueous solution by gamma irradiation was investigated. The effect of the irradiated solution composition was studied. The results showed that benzene is more resistant to destruction than chlorinated benzenes. The presence of oxidizing and reducing reactive species and the rapid reaction rates with halogenated benzenes increased the degradation rate of the pollutants. Dechlorination of CB and 1,2-DCB was observed. High performance liquid chromatography (HPLC) and spectroscopy (UV-Vis) were used to monitor changes in the radiation solutions. The final aqueous irradiation products were shown to be a complex mixture of by-products. The addition of scavengers such as methanol and ethanol required larger doses to decompose the pollutants when compared to those solutions with no additives.
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Sahri, Moch, Gilang Nugraha, Abraham Ahmad Ali Firdaus, Rizka Wahyu Safitri, and Nur Muhamad Nuzulul Syufi. "Pemeriksaan Profil Darah Pada Pekerja Sebagai Upaya Deteksi Dini Gangguan Kesehatan Akibat Paparan Uap Benzene di Industri Percetakan." JURNAL KREATIVITAS PENGABDIAN KEPADA MASYARAKAT (PKM) 4, no. 6 (December 1, 2021): 1338–42. http://dx.doi.org/10.33024/jkpm.v4i6.4355.
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ABSTRAK Berdasarkan penelitain sebelumnya diketahui bahwa lokasi kegiatan pengabdian masyarakat, didapatkan hasil pengukuran kadar uap benzene dilingkungan kerja dengan kisaran 0,3-1,5 ppm. Anemia aplastik yang disebabkan oleh penekanan sumsum tulang adalah penyebab klasik kematian akibat keracunan benzena kronis. Tujuan dari kegiatan ini adalaha untuk melakukan pemeriksaan profil darah pekerja yang terpapar benzene dilingkungan kerjanya sebagai upaya antisipasi dan deteksi dini penyakit akibat paparan benzene. Kegiatan pemeriksaan profil darah dilakukan dengan menerapkan protokol Kesehatan. Pengambilan dan anlisa profil darah dilakukan oleh laboratorium yang kompeten. Jumlah pekerja yang terlibat dalam kegiatan ini sebanyak 10 pekerja dengan jenis kelamin laki-laki dengan kriteria pekerja yang terpapar langsung dengan uap benzene dilingkungan kerjanya. Hasil dari pemeriksaan 10 orang pekerja didapatkan hasil leukosit 6,97 ± 0,8, hemoglobin 15,3 ± 0,92 dan trombonist 212,1 ± 25,07. Kegiatan pengabdian masayarakat berjalan sesuai dengan jadwal yang telah direncanakan. Hasil pemeriksaan profil darah pada 10 pekerja masih dalam batas nilai rujukan. Kata Kunci : benzene, profil darah, industri percetakan ABSTRACT Based on previous research, it is known that the location of community service activities, the results of measurements of benzene vapor levels in the work environment are in the range of 0.3-1.5 ppm. Aplastic anemia caused by bone marrow compression is the classic cause of death from chronic benzene poisoning. The purpose of this activity is to examine the blood profile of workers exposed to benzene in their work environment to anticipate and detect diseases due to benzene exposure. Blood profile examination activities were carried out by applying the Covid Health protocol 19. Blood profile collection and analysis were carried out by a competent laboratory. The number of workers involved in this activity was 10 workers of the male gender with the criteria that workers were directly exposed to benzene vapor in their work environment. The results of the examination of 10 workers showed leukocytes 6.97 ± 0.8, hemoglobin 15.3 ± 0.92, and trombone 212.1 ± 25.07. Community service activities go according to the planned schedule. The results of blood profile examinations on 10 workers are still within the reference value limit. Keywords: benzene, blood profile, printing industry
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Schraml, Jan, Robert Brežný, Jan Čermák, and Václav Chvalovský. "29Si and 13C NMR spectra of some substituted bis(trimethylsiloxy)benzenes." Collection of Czechoslovak Chemical Communications 55, no. 8 (1990): 2033–37. http://dx.doi.org/10.1135/cccc19902033.
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NMR spectra of a few 4-substituted 1,2-bis(trimethylsiloxy)benzenes and positional isomers of bis(trimethylsiloxy)benzene were measured under standard conditions that approach those of infinite dilution. Under these conditions somewhat smaller values of steric or proximity deshielding effects on 29Si chemical shifts are found but the trends established earlier are confirmed; the deshielding effect of the ìsecondî ortho positioned trimethylsiloxy group in a tris(trimethylsiloxy)benzene derivative on 29Si chemical shifts is somewhat smaller. Also, overcrowding of three trimethylsiloxy groups probably drives the outer groups to assume, at least for a part of their time, coplanar conformation which is not encountered in bis(trimethylsiloxy) derivatives. The sensitivity of 29Si chemical shifts to para substitution is in 1,2-bis(trimethylsiloxy)benzenes equal to that in 2-methoxytrimethylsiloxybenzenes.
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Nasa, Yola Noveraz, Nugraha Sutadipura, and Santun Bhekti Rahimah. "Scoping Review: Pengaruh Bensin terhadap Peningkatan Kadar LDL pada Plasma Darah Tikus." Jurnal Integrasi Kesehatan & Sains 3, no. 1 (March 24, 2021): 104–9. http://dx.doi.org/10.29313/jiks.v3i1.7382.
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Konsumsi bensin sejak tahun 2000 sampai 2014 meningkat seiring dengan peningkatan jumlah kendaraan bermotor setiap tahun. Bensin memiliki dampak negatif terhadap lingkungan berupa polusi dan terhadap kesehatan seperti gangguan paru, ginjal, penyakit kulit, serta perubahan profil lipid berupa peningkatan kadar low-density lipoprotein (LDL) yang dapat meningkatkan angka kejadian penyakit jantung koroner dan sindrom metabolik. Tujuan penelitian mengetahui pengaruh paparan bensin terhadap kadar LDL pada plasma darah manusia yang dimulai dengan kajian terhadap hewan coba. Metode penelitian yang digunakan yaitu deskriptif dengan prosedur scoping review dengan cara mengidentifikasi, menganalisis dan mengevaluasi karya ilmiah sesuai dengan kriteria inklusi dan eksklusi serta diskrining menggunakan kriteria kelayakan (Eligibility criteria). Hasil penelitian didapatkan sepuluh artikel dari jumlah awal 10.486 artikel yang ditemukan dari kata kunci. Sepuluh artikel yang sesuai dengan PICO (Population: tikus; Intervention: bensin, lead atau benzene; Comparison: tikus yang tidak dipaparkan bensin, lead atau benzene; Outcome: kadar LDL pada plasma darah) menunjukkan peningkatan kadar LDL plasma pada kelompok tikus yang diberi paparan bensin, timbal atau benzena daripada kelompok kontrol. Hal tersebut diakibatkan stres oksidatif dari induksi lead atau benzene yang menekan aktivitas antioksidan dan meningkatkan reactive oxygen species di tubuh sehingga terjadi cidera hepar dan metabolisme lipoproteinpun terganggu. Pada akhirnya bensin yang memiliki komponen benzene atau lead mengakibatkan peningkatan kadar LDL plasma. Kesimpulan penelitian terdapat pengaruh bensin terhadap kadar LDL pada plasma darah tikus dan beberapa komponen bensin yang berperan, yaitu timbal dan benzena. Scoping Review: Effect of Gasoline on Increasing Blood Plasma LDL Levels in Rats Gasoline consumption from 2000 to 2014 increased along with the increase in the number of motorized vehicles each year. Gasoline harms the environment in the form of pollution and on the health of lung, kidney, skin diseases, and changes in the lipid profile in the form of increased levels of low-density lipoprotein (LDL) which can increase the incidence of coronary and metabolic heart disease. This study aimed to determine the effect of gasoline exposure on LDL levels in human blood plasma starting with a study of experimental animals. The research method used is descriptive with a scoping review procedure by identifying, analyzing, and evaluating scientific papers according to inclusion and exclusion criteria and screening using eligibility criteria. The research results obtained ten articles from the initial number of 10,486 articles found from keywords. Ten PICO-compliant articles (Population: rats; Intervention: gasoline, lead or benzene; Comparison: rats not exposed to gasoline, lead or benzene; Results: LDL levels in blood plasma) showed increased plasma LDL levels in the group of rats exposed to gasoline, lead or benzene control group. This is due to oxidative stress from lead or benzene induction which suppresses antioxidant activity and increases reactive oxygen species in the body, resulting in liver injury, impaired lipoprotein metabolism. In the end, gasoline which has benzene or lead component causes an increase in plasma LDL levels. This study concludes that there is an effect of gasoline on LDL levels in rat blood plasma, and several components of gasoline that play a role, namely lead and benzene.
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Roesyadi, A. "Hidrogenasi Benzen." REAKTOR 8, no. 1 (June 19, 2017): 22. http://dx.doi.org/10.14710/reaktor.8.1.22-28.
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Penelitian ini bertujuan mempelajari unjuk kerja katalis ruthenium dan rhodium yang disupport dengan karbon aktif pada reaksi hidrogenasi benzene pada fasa cair dengan pelarut asam asetat. Percobaan dilakukan dalam reaktor bertekanan yang dilengkapi dengan pengaduk mekanis, indicator tekanan, termokopel dan jaket pemanas. Variabel penelitian adalah temperatur yaitu pada 30 0C, 50 0C, 75 0C, 100 0C, 125 0C dan 150 0C. sedangkan tekanan dilakukan pada 9 atm dan persentase katalis Metal C sebesar 5%. Analisa hasil dilakukan dengan Gas Chromatographi dengan memakai standar intern Toluen yang terpisah secara baik dengan benzen maupun sikloheksana sebagai produk reaksi hidrogenasi. Dari hasil penelitian didapat bahwa reaksi hidrogenasi benzen menjadi sikloheksana dengan katalis 5% Ruthenium yang disupport dengan karbon aktif memerlukan energy aktivasi sebesar 1416, 73 kal/mol, sedangkan dengan katalis Rhodium sebesar 110,202 kal/mol.energi aktivasi yang rendah, menunjukkan bahwa reaksi hidrogenasi benzene menjadi sikloheksana dikontrol oleh transfer massa. Hasil sikloheksana bias dianalisis secara kualitatif mulai pada suhu 30 0C. sikloheksana yang terbanyak diperoleh pada suhu 150 0C. Dengan menganggap bahwa konsentrasi H2 dalam larutan selalu konstan , reaksi ini mengikuti orde nol terhadap benzene.Kata kunci : hidrogenasi, reaktor batch, benzene
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Prince Junior Asilevi, Daniel Akambawe, Chengwu Yu, Jue Li, Patrick Boakye, Sampson Oduro-Kwarteng, and Muhammad Imran Nawaz. "Research on the electrical characteristics of atmospheric strong ionization dielectric barrier discharge for air pollution control." Maejo International Journal of Energy and Environmental Communication 2, no. 1 (April 20, 2020): 50–59. http://dx.doi.org/10.54279/mijeec.v2i1.244953.
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The specific input energy (SIE), current density, and discharge power of homemade strong ionization dielectric barrier discharge (DBD) were studied to suppress gas-phase benzene at atmospheric pressure efficiently. Findings indicate that for 300 ppm of benzene at 3.5 kJ/L SIE, benzene's removal efficiency reached 96%. The decline in current density by 66.48% and 43.7% for an initial benzene concentration of 300 ppm was due to increased oxygen content (from 2.4% to 20.9%) and relative humidity (from 18.9% to 90%), respectively, thus reducing electron concentration and consequentially enhanced the removal efficiency over 93%.Furthermore, the decomposition law's beta parameter decreased from 3.1 kJ/L at 300 ppm to 1.6 kJ/L at 100 ppm, indicating that •O and •OH radicals are key species for the decomposition of benzene and electron dissociation reactions largely control the process. The Maxwell– Boltzmann electron energy distribution function was solved using the average energy of the strong ionization discharge reactor (~10 eV), showing that approximately 84.8 % of high energy electrons possess enough energy to cause the benzene ring cleavage and free radical production. The study results show that the strong ionization DBD plasma reactor is highly efficient in removing benzene from industrial waste air, hence air pollution control.
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Resdwivani, Diva Madya. "Air Benzene’s Concentration, Urine Trans,Trans-Muconic Acid’s Concentration and Health Disturbance of X’s Fuel Station Employee in South Jakarta." JURNAL KESEHATAN LINGKUNGAN 10, no. 2 (December 4, 2018): 159. http://dx.doi.org/10.20473/jkl.v10i2.2018.159-164.
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Benzene is an aromatic compound which is easy to evaporate that is found in fuel oil. Benzene in the air can affect to human’s health if inhaled because benzene can be metabolized in the body. The aim of this research was analyze benzene’s concentration in air on X’s fuel station in South Jakarta, urine trans,trans-muconic acid’s concentration, and health disturbance of fuel station’s employee. This research was a descriptive with cross-sectional study. There were 8 respondents in this research with defined criteria. X’s fuel station air benzene’s concentration be measured in 3 points (2 points in filling area and 1 point in office area) on 2 different times (in the morning and in the afternoon). The result of this research, X’s fuel station air benzene’s concentration were 0,025–0,233 ppm and there was no air benzene’s concentration more than the threshold values (0,5 ppm) in filling area or administration area. There were 3 of 8 respondents had trans,trans-muconic acid’s levels that is more than 500 μg/g creatinin. Health disturbance that experienced by workers were nervous system disorders (62%) and kidney disturbance (50%). Therefore, workers should use PPE such as respirator mask and company should do rotation for workers.
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Shimizu, Tomoe, Takayuki Maeda, Katsuhiro Hida, and Takehiko Yamato. "Synthesis and conformational studies of 9-methoxy- and 9-methyl-2,11-dithia[3.3]metacyclophanes." Journal of Chemical Research 2009, no. 8 (August 2009): 515–19. http://dx.doi.org/10.3184/030823409x12474221035244.
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A series of 9-methoxy- and 9-methyl-2,11-dithia[3.3]metacyclophanes are obtained by the coupling reaction of the corresponding 1,3-bis(bromomethyl)benzenes and bis(sulfanylmethyl)benzenes in ethanol under the high dilution conditions. The conformational studies of 2,11-dithia[3.3]metacyclophanes as well as the ring current interactions derived from benzene ring are also described.
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Zou, Chunhai, Christine Lepetit, Yannick Coppel, and Remi Chauvin. "Ring carbo-mers: From questionable homoaromaticity to bench aromaticity." Pure and Applied Chemistry 78, no. 4 (January 1, 2006): 791–811. http://dx.doi.org/10.1351/pac200678040791.
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The title journey is undertaken at the levels of both theory and experiment. Since 1983, homoaromaticity has been shown to play at most a minor role in the stability of Scott's [N]pericyclyne hydrocarbons - the first ring carbo-mers of cycloalkanes. This statement has been systematically refined for N = 3-6 by using both classical theoretical tools and newly designed tools based on electron localization function (ELF) analysis. The compatibility of the [5]- and [6]-pericyclyne cores with vertex functionalities was established by the synthesis of 20 oxy (carbo-cyclitol) derivatives. The stereoisomeric resolution of two of them has been achieved. Hexaoxy-[6]pericyclynes are actually potential precursors of the carbo-benzenes. Criteria based on density functional theory (DFT) calculations (magnetic, energetic, structural/"electronic") show that the aromaticity of carbo-[N]annulenic species is comparable to that of their parent molecule. This has been challenged by the synthesis of several novel carbo-benzenic molecules with various substitution patterns. The theory-experiment interplay is pursued by considering ring carbo-mers of other conjugated ring systems such as radialenes. The second carbo-mers (butadiyndiyl-expanded rings) of [3]radialene and benzene are also envisioned. Hexaphenyl-carbo2-benzene has been observed by 1H and UV-vis spectroscopy.
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Agustriyanto, Rudy, Lanny Sapei, Endang Srihari Mochni, and Puguh Setyopratomo. "Process Design of Benzene Nitrification." Keluwih: Jurnal Sains dan Teknologi 4, no. 1 (March 23, 2023): 13–20. http://dx.doi.org/10.24123/saintek.v4i1.5391.
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Abstract—Aspen HYSYS was used to investigate several aspects of process design for benzene nitration. In this study, the frequency factor (ko) and the activation energy (Ea) for benzene nitration were given from the literature. Calculations of chemical and physical properties were performed automatically on Hysys using the NRTL and UNIQUAC Thermodynamic models. Some aspects of process design were studied, namely: (1) the effect of temperature on the conversion of reactions, (2) the effect of the ratio of sulphuric acid to nitric acid on the synthesis of nitrobenzen in the reactor, and (3) the effect of reactor arrangements ( parallel and series) on reaction conversion. The results showed that the peak of conversion that could be achieved on a single reactor was 96.9% at a ratio of sulfuric acid: nitric acid = 3.5 and a temperature of 50ºC. However, based on this study, it is suggested that the most favorable conditions for nitation of benzene in an isothermal reactor are 50°C and a sulfuric acid:nitric acid ratio of about 2.5 to 3.
Abstrak—Aspen HYSYS digunakan untuk menginvestigasi beberapa aspek perancangan proses pada nitrasi benzen. Energi aktivasi (Ea) dan faktor frekwensi (ko) untuk reaksi ini diperoleh dari literature. Perhitungan sifat-sifat fisis dan kimia dilakukan secara otomatis pada Hysys dengan menggunakan model Termodinamik NRTL dan UNIQUAC. Beberapa aspek perancangan proses dipelajari dengan simulasi, yaitu: pengaruh suhu pada konversi reaksi, pengaruh rasio asam sulfat terhadap asam nitrat pada sintesa nitrobenzen dalam CSTR (reaktor berpengaduk kontinyu), dan pengaruh susunan reaktor baik seri maupun parallel terhadap konversi reaksi. Hasil penelitian menunjukkan bahwa konversi tertinggi yang dapat dicapai pada CSTR tunggal adalah 96,9 % pada rasio asam sulfat: asam nitrat = 3,5 dan suhu 50ºC. Namun demikian, berdasarkan penelitian ini, disarankan bahwa kondisi yang paling disukai untuk nitasi benzen dalam CSTR isotermal adalah 50ºC dan rasio asam sulfat:asam nitrat sekitar 2,5 sampai 3.
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Agustriyanto, Rudy, Lanny Sapei, Endang Srihari Mochni, and Puguh Setyopratomo. "Process Design of Benzene Nitrification." Keluwih: Jurnal Sains dan Teknologi 4, no. 1 (March 23, 2023): 13–20. http://dx.doi.org/10.24123/saintek.v3i2.5391.
Full textAbstract:
Abstract—Aspen HYSYS was used to investigate several aspects of process design for benzene nitration. In this study, the frequency factor (ko) and the activation energy (Ea) for benzene nitration were given from the literature. Calculations of chemical and physical properties were performed automatically on Hysys using the NRTL and UNIQUAC Thermodynamic models. Some aspects of process design were studied, namely: (1) the effect of temperature on the conversion of reactions, (2) the effect of the ratio of sulphuric acid to nitric acid on the synthesis of nitrobenzen in the reactor, and (3) the effect of reactor arrangements ( parallel and series) on reaction conversion. The results showed that the peak of conversion that could be achieved on a single reactor was 96.9% at a ratio of sulfuric acid: nitric acid = 3.5 and a temperature of 50ºC. However, based on this study, it is suggested that the most favorable conditions for nitation of benzene in an isothermal reactor are 50°C and a sulfuric acid:nitric acid ratio of about 2.5 to 3.
Abstrak—Aspen HYSYS digunakan untuk menginvestigasi beberapa aspek perancangan proses pada nitrasi benzen. Energi aktivasi (Ea) dan faktor frekwensi (ko) untuk reaksi ini diperoleh dari literature. Perhitungan sifat-sifat fisis dan kimia dilakukan secara otomatis pada Hysys dengan menggunakan model Termodinamik NRTL dan UNIQUAC. Beberapa aspek perancangan proses dipelajari dengan simulasi, yaitu: pengaruh suhu pada konversi reaksi, pengaruh rasio asam sulfat terhadap asam nitrat pada sintesa nitrobenzen dalam CSTR (reaktor berpengaduk kontinyu), dan pengaruh susunan reaktor baik seri maupun parallel terhadap konversi reaksi. Hasil penelitian menunjukkan bahwa konversi tertinggi yang dapat dicapai pada CSTR tunggal adalah 96,9 % pada rasio asam sulfat: asam nitrat = 3,5 dan suhu 50ºC. Namun demikian, berdasarkan penelitian ini, disarankan bahwa kondisi yang paling disukai untuk nitasi benzen dalam CSTR isotermal adalah 50ºC dan rasio asam sulfat:asam nitrat sekitar 2,5 sampai 3.
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Panggabean, Aman Sentosa, Tika Widyastuti, and Noor Hindryawati. "Validasi Metode Penentuan Benzena, Toluena dan Xilena pada Sampel Udara dan Tanah Menggunakan Kromatografi Gas." ALCHEMY Jurnal Penelitian Kimia 15, no. 1 (March 1, 2019): 177. http://dx.doi.org/10.20961/alchemy.15.1.25522.177-189.
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<p>Penelitian tentang validasi metode penentuan kadar benzena, toluena dan xilena pada sampel udara dan tanah dengan menggunakan kromatografi gas telah dilakukan. Untuk mendapatkan hasil pengukuran yang valid, beberapa parameter penting yang berpengaruh dalam validasi metode telah ditentukan. Beberapa parameter penting yang dilakukan adalah penentuan besaran dasar kromatografi yang meliputi: waktu retensi, kapasitas (k’), faktor selektivitas (α) dan kinerja analitik yang meliputi: penentuan linearitas (r), limit deteksi (LOD), limit kuantitasi (LOQ), presisi dan akurasi. Hasil penelitian penentuan kinerja analitik sangat baik ditunjukkan oleh nilai presisi sebagai % KV < 2/3 nilai KV Horwitz, LOD untuk masing-masing senyawa benzena, toluena dan xilena adalah 0,02 mg/L; 0,59 mg/L dan 0,08 mg/L serta LOQ untuk masing-masing senyawa benzena, toluena dan xilena adalah 0,07 mg/L; 1,99 mg/L dan 0,27 mg/L. Akurasi metode ini sangat baik ditunjukkan dengan nilai presentase perolehan kembali masing-masing senyawa benzena, toluena dan xilena untuk sampel tanah sebesar 102,61 ± 4,61%; 101,65 ± 7,41%; 102,15 ± 4,15%, dan untuk sampel udara masing-masing senyawa sebesar 101,69 ± 5,77%; 102,08 ± 5,43% dan 98,55 ± 5,11%. Berdasarkan hasil penelitian ini, metode kromatografi gas dapat digunakan dalam penentuan benzena, toluena dan xilena pada sampel udara dan tanah dengan memberikan hasil yang valid.</p><p><strong>Validation Method </strong><strong>o</strong><strong>n The Determination </strong><strong>o</strong><strong>f Benzene, Toluene </strong><strong>a</strong><strong>nd Xylene </strong><strong>i</strong><strong>n Air </strong><strong>a</strong><strong>nd Soil Samples Using Gas Chromatography. </strong>The present study investigated the method for the determination of the content of benzene, toluene, and xylene in air and soil samples using gas chromatography. To obtain a valid measurement result, several important parameters that influence the method validation have been determined. The several important parameters carried out are the determination of the basic chromatographic such as retention time, capacity factor (k'), selectivity (α) and analytical performance measurement includes: the determination of linearity (r), limit of detection (LOD), limit of quantitation (LOQ), precision and accuracy. The result of analytical performance of the research are well verified, in which the value of precision was % CV < 2/3 CV Horwitz value, LOD for benzene, toluene, and xylene compound were 0.02 mg/L, 0.59 mg/L, 0.08 mg/L, respectively, and LOQ for benzene, toluene and xylene compounds was 0.07 mg/L, 1.99 mg/L and 0.27 mg/L respectively. This method achieved high accuration, indicated by a percentage of recovery value of benzene, toluene, and xylene for soil samples of 102.61 ± 4.61%; 101.65 ± 7.41%; 102.15 ± 4.15%, and for air samples was 101.69 ± 5.77%, 102.08 ± 5.43%, and 98.55 ± 5.11% respectively. Based on the results of this research, the method presented in this study can be applied for the determination of benzene, toluene, and xylene using gas chromatography in air and soil samples with valid results.</p>
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Suhartono, S., Herri Susanto, Dwiwahju Sasongko, and Azis Trianto. "Pengukuran konstanta henry toluen dan benzen dalam minyak dan air dengan kolom gelembung." Jurnal Teknik Kimia Indonesia 9, no. 2 (October 2, 2018): 49. http://dx.doi.org/10.5614/jtki.2010.9.2.2.
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Determination of Henry’s constant for toluene and benzene in oils and water were carried out in a bubbling bottle with diameter of 3 cm. Air containing toluene vapour or benzene vapour was bubbled through 50 mL absorbing liquid. The gas flow rate was 13.6 mL/min. By measuring the concentration of toluene or benzene in the inlet and outlet gas stream, we were able to calculate their concentrations in absorbing liquid. We found that the value of Henry’s constant of toluene in lubrication oil and palm oil at 30 oC were 155 and 145 respectively (H= CG/CL, with CG in mol/L and CL in mol/L). We also found that the absorption capacities were in the order (from the highest) of: lubrication oil, palm oil, and sunflower oil. Henry’s constant of toluene in water was at about 4 which was much lower than those of oils.Keyword: absorption, Henry’s constant, toluene, benzene, producer gas AbstrakPengukuran konstanta Henry sistem toluen dan benzen dalam minyak dan air dilakukan melalui percobaan absorpsi di dalam sebuah kolom gelembung dengan diameter 3 cm. Minyak sawit, minyak bunga matahari, minyak pelumas dan air digunakan sebagai absorben. Toluen dan benzen dipilih sebagai tar model. Gas model yang tersusun dari udara dan uap toluen atau benzen digelembungkan ke dalam absorben 50 mL. Absorpsi dilakukan pada suhu 30 dan 60 oC dan laju alir gas model 13,6 mL/min. Analisa dilakukan terhadap konsentrasi aliran gas model sebelum dan sesudah absorpsi. Analisa tersebut dilakukan dengan kromatografi gas Shimadzu GC-8APF. Konstanta Henry dihitung sebagai H=CG/CL dan H=P/CL. Nilai 1/H sistem toluen-minyak pelumas dan toluen-minyak sawit pada suhu 30 oC dan laju alir gas 13,6 mL/min berturut-turut adalah 155 dan 145 (untuk CG dalam mol/L dan CL dalam mol/L). Merujuk pada nilai-nilai konstanta Henry hasil percobaan, minyak pelumas dan minyak sawit merupakan cairan penyerap yang paling cocok untuk toluen dan benzen sebagai representasi tar dalam gas hasil gasifikasi. Urutan besarnya kapasitas absorpsi cairan penyerap terhadap toluen dan benzen adalah sebagai berikut (berturut-turut dari yang besar): minyak pelumas, minyak sawit, minyak bunga matahari dan air. Konstanta Henry toluen dalam air berada pada kisaran 4, yang menunjukkan bahwa kapasitas absorpsi toluen dalam air lebih rendah dibandingkan kapasitas absorpsi toluen dalam minyak.Kata Kunci: absorpsi, konstanta Henry, toluen, benzen, gas produser
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Chow, Yuan L., and Xinxin Ouyang. "The photoaddition of 1,3-diketonatoboron difluorides with benzene derivatives." Canadian Journal of Chemistry 69, no. 3 (March 1, 1991): 423–31. http://dx.doi.org/10.1139/v91-064.
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The boron difluoride complexes of 2-acetylcyclohexanone, 2-acetylcyclopentanone, and acetylacetone (abbreviated as ACHBF2, ACPBF2, and AABF2) were irradiated in the presence of benzene to give the 1:1 adducts as the primary photoadducts; for certain BF2 complexes, toluene, chlorobenzene, benzonitrile, and methyl benzoate were also used as substrates. The 1,5-diketone photoadducts were assumed to form by a [2+2] photocycloaddition followed by cyclobutane opening and hydrolysis to give 1,2 adducts. They undergo a variety of secondary thermal reactions, probably acid catalyzed, to give enol ethers, enol acetates, acetophenones, and ketonylacetophenones. The efficiency of these secondary reactions determines the final products. Photoaddition with a monosubstituted benzene preferentially occurs at the 3,4 bond without regioselectivity. Under oxygen, ACHBF2 photolytically reacts with benzene to give a secondary oxidation product of a 10-membered cyclic alkylphe-none, which is proven by X-ray crystallographic analysis to have the benzene ring and carbonyl group in orthogonal orientation. It is shown that the singlet excited state ACHBF2 initiates the photoaddition, probably through the formation of the benzene exciplex, which could be detected by its emission. While the Stern–Volmer rates are small, the quantum yield of photoaddition products is as high as 0.12–0.19 under limiting conditions. Key words: [2+2] photocycloaddition, non-planar alkanophenone, macrocyclic alkanophenone, boron difluoride complexes, photoaddition to benzenes.
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Wu, Yuezhengfei. "Comprehensive Analysis of Benzene: Synthesis, Applications, and Environmental Impacts." Highlights in Science, Engineering and Technology 83 (February 27, 2024): 181–87. http://dx.doi.org/10.54097/5z3hze71.
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As a cornerstone in producing fuels, plastics, pharmaceuticals, and other commodities, benzene catalyzes innovation and modern convenience. However, its simultaneous classification as a Group 1 carcinogen necessitates a nuanced understanding of its potential detriments alongside its benefits. This concise but comprehensive paper explores the complex characteristics and pervasive influence of benzene, a compound integral to numerous industries and facets of daily life. This study meticulously delineates the adverse health implications of benzene exposure, with a particular focus on its role in the onset of various leukemias. Moreover, the research scrutinizes the environmental repercussions of benzene dissemination through industrial emissions, vehicular exhaust, and other prevalent sources, elucidating its detrimental impact on air, water, soil, and broader ecosystems. In light of these pressing concerns, the paper highlights ongoing initiatives striving to curtail benzene-induced pollution and enhance air quality. These efforts encompass the implementation of stringent regulatory frameworks, the development of cleaner fuel alternatives, and the advancement of emission control technologies. As people navigate towards a future that is both sustainable and health-conscious, the imperative lies in fostering a symbiotic relationship between leveraging benzene's utilities and minimizing its potential hazards to both human health and the environment.
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Jabbar, Baneen Hayder, Ibtisam A. Al-Ali, and Khalid Ali Hussein. "Effect of Spanish Black Radish Extract Against Benzyne Induced Toxicity in Rats." IOP Conference Series: Earth and Environmental Science 1215, no. 1 (July 1, 2023): 012060. http://dx.doi.org/10.1088/1755-1315/1215/1/012060.
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Abstract Benzene is one of the main products of the petrochemical industry worldwide, which causes aplastic anemia and leukemia in both people and animals. This study was designed to examine the modulatory effects of black radish on Benzene-induced toxicity in male rats. Thirty-five rats were divided into 7 groups (5 rats in each group), G1 negative control group; G2 positive control group (benzene treated group); G3 and G4 were treated after development of leukemia with Black radish aqueous extract (100mg/kg and 200 mg/kg respectively), while G5 and G6 were treated with Black radish ethanolic extract (100mg/kg and 200 mg/kg and G7 was treated with cyclophosphamide. Significant pathological variations in the liver, kidney and spleen tissues were detected in all experimental groups except for the control group. Our results indicate that benzyne induces irreversible adverse effects on the livers, kidneys, and spleen of rats.
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Boinski, Tomasz, and Agnieszka Szumna. "Hybrid[4]arenes with anthracene units and tuneable cavities." New Journal of Chemistry 41, no. 9 (2017): 3387–91. http://dx.doi.org/10.1039/c7nj00039a.
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Acid catalyzed condensation between tetramethoxyanthracenes and formaldehyde in the presence of additional benzene-based building blocks leads to hybrid macrocyclic products that are further modified by the Diels–Alder reaction with benzyne to obtain macrocycles with expanded cavities.
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Baum, Jeremy, Leonor Cruzeiro-Hansson, and John Finney. "Electron-Benzene and Benzene-Benzene Potentials for Simulation of an Excess Electron in Liquid Benzene." Physica Scripta T33 (January 1, 1990): 71–76. http://dx.doi.org/10.1088/0031-8949/1990/t33/011.
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Petersen, Dirk, Martina Lemmrich, Matthias Altrogge, and Jürgen Voss. "Notizen: Elektroreduktion organischer Verbindungen, XV [1] / Electroreduction of Organic Compounds, XV [1]." Zeitschrift für Naturforschung B 45, no. 7 (July 1, 1990): 1105–7. http://dx.doi.org/10.1515/znb-1990-0736.
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The twelve possible chlorinated benzenes and the three isomeric monochlorobiphenyls are electrochemically reduced in a divided cell in methanol at a lead cathode. Chlorobenzene and benzene or biphenyl, respectively, are formed with acceptable current yields and very good chemical yields.
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Ariobimo, Mumammad Pasha, Adyati Pradini Yudison, and Moh Irsyad. "Identifikasi Senyawa Benzena pada Kabin Mobil." Jurnal Ilmu Lingkungan 21, no. 1 (October 3, 2022): 15–21. http://dx.doi.org/10.14710/jil.21.1.15-21.
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Interior mobil yang pada umumnya terbuat dari bahan-bahan sintetis yang dapat mengemisikan Volatile Organic Compound (VOC) apabila berada pada suhu yang tinggi, salah satunya adalah senyawa benzene. Selain berasal dari emisi bahan-bahan yang digunakan pada interior mobil, konsentrasi senyawa benzena dapat pula dipengaruhi oleh hal lain, diantaranya: kondisi udara ambien, kebocoran gas dari tangki bahan bakar dan tabung penghantar bahan bakar, infiltrasi emisi kendaraan lain di tempat parkir, dan lain sebagainya. Pada penelitian ini akan dibandingkan konsentrasi benzene di dalam kabin mobil pada 3 kondisi berbeda, yaitu berdasarkan durasi penjemuran mobil 2 jam, 4 jam, dan 6 jam secara active sampling dan dianalisis menggunakan gas kromatografi-spektrometer massa (GC-MS). Sebagai pembanding, akan diukur pula konsentrasi benzena pada mobil yang ditempatkan di dalam garasi tanpa terpapar sinar matahari secara langsung. Hasil penelitian terukur keberadaan benzena di dalam kabin mobil pada kondisi tanpa ventilasi dan pendingin dengan konsentrasi antara 0.77 – 1.36 mg/m³. Konsentrasi tersebut berkorelasi signifikan secara statistik dengan temperatur dalam kabin sehingga semakin tinggi temperatur akan semakin tinggi pula konsentrasi benzena di dalam kabin mobil. Terdapat pula kemungkinan infiltrasi benzena dari lingkungan luar mobil. Hasil penelitian ini meningkatkan kesadaran pengguna mobil mengenai adanya pencemar udara berbahaya pada kabin mobil saat sedang tidak dipergunakan terutama apabila berada pada tempat dengan temperatur tinggi dan terdapat sumber pencemar benzenekabin mobil, benzena, GC-MS , VOC
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Kitamura, Tsugio, Rin Yamada, Keisuke Gondo, Nobuo Eguchi, and Juzo Oyamada. "Copper-Free Double Silylation of 1,2-Dibromobenzenes Using a Mg/LiCl/DMI System." Synthesis 49, no. 11 (February 22, 2017): 2495–500. http://dx.doi.org/10.1055/s-0036-1588726.
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The reaction of 1,2-dibromobenzenes with chlorotrimethylsilane efficiently proceeded in the presence of Mg and LiCl in DMI under mild conditions, giving 1,2-bis(trimethylsilyl)benzenes in good to high yields. The reaction of 1,2-dibromobenzenes with chlorodimethylsilane under the same conditions afforded the corresponding 1,2-bis(dimethylsilyl)benzenes in high yields. Functional group transformations of 1,2-bis(trimethylsilyl)benzene were conducted to demonstrate the synthetic utility.
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Brownstein, Sydney, Anne Morrison, and Liang K. Tan. "Ternary charge transfer complexes. II. Complexes with Group III and IV elements in the anion." Canadian Journal of Chemistry 64, no. 2 (February 1, 1986): 265–69. http://dx.doi.org/10.1139/v86-045.
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Intensely colored charge transfer complexes are formed from NOMX4 (M = B,Al,Ga,Tl; X = Cl,F) and benzene or methyl substituted benzenes. (NO)2MX6 (M = Si,Ge,Sn,Tl; X = Cl,F) also form complexes with methyl substituted benzenes. Magnetic resonance and optical spectroscopic parameters are presented. NOMX4 forms stronger complexes than (NO)2MX6 and complexes containing fluorine are stronger than those with chlorine.
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Abasov, S. I., S. B. Agaeva, M. T. Mamedova, Y. S. Isaeva, A. A. Iskenderova, and D. B. Tagiyev. "EFFECT OF AN ALKYL SUBSTITUTE ON HYDROCONVERSION OF INDIVIDUAL AROMATIC HYDROCARBONS ON Co/HZSM-5/SO42-–ZrO2 COMPOSITE CATALYST." Azerbaijan Chemical Journal, no. 2 (May 7, 2024): 36–43. http://dx.doi.org/10.32737/0005-2531-2024-2-36-43.
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A systematic study of the hydrogenation of individual aromatic hydrocarbons (benzene, toluene, xylene) and their mixtures was carried out at 1800C, H2/Ar=7, WHSV = 2h-1 and atmospheric pressure on a composite catalyst 0.4%Co/HZSM-5/SO42-(2.0%)–ZrO2. It has been established that the developed catalyst has a high hydrogenating ability with respect to aromatic hydrocarbons at low hydrogen pressures. Alkyl-substituted benzenes turned out to be more active. It was found that alkyl substituents increase the activity of hydrogenation of the benzene ring of an aromatic hydrocarbon. According to their conversion, benzene, toluene and xylene form the following sequence: benzene<toluene<xylene. It was found that the optimal temperature for the process of hydroconversion of aromatic hydrocarbons on a composite catalyst is 1800C. The influence of the concentration of the hydrogenating component of the catalyst – Co on the hydroconversion was also investigated. It was found that the optimal concentration of Co is 0.4wt %. It has been established that in a benzene:toluene:xylene mixture, the conversion of benzene in comparison with its separate hydroconversion increases by more than 10%. The hydroconversion of aromatic hydrocarbons is accompanied by the formation of high-octane naphthenic hydrocarbons - cyclohexane, methylcyclohexane and methylcyclopentane. The antibatic change in the yield of CH and MCP with the duration of the experiment shows that the hydrogenation of the aromatic ring is primary and the isomerization of C6H10 to MCP is secondary, i.e. MCP is the result of a sequential transformation. The absence of dimethylcyclohexane (DMCH) in the benzene:toluene:xylene mixture conversion products suggests that the benzene and xylene conversions additionally involve transalkylation
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Knežević, Nikola Ž., Sladjana B. Novaković, and Goran A. Bogdanović. "Monomolecular sheets of propeller-shaped triethyl 4,4′,4′′-[benzene-1,3,5-triyltris(ethyne-2,1-diyl)]tribenzoate deuterochloroform monosolvate." Acta Crystallographica Section C Structural Chemistry 70, no. 10 (September 4, 2014): 937–40. http://dx.doi.org/10.1107/s2053229614019147.
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The title compound, C39H30O6·CDCl3, has a chemical threefold axis and an approximately planar structure, with an ethoxycarbonyl substituent on each of the terminal benzenes oriented in the same direction, thus forming a propeller-shaped molecule. This molecule is of particular interest in the field of metal–organic frameworks (MOFs), where its hydrolyzed analogue forms MOF structures with high surface areas. The benzene ring which occupies the centre of the molecule forms π–π interactions to the equivalent benzene ring at a perpendicular distance of 3.32 (1) Å. Centrosymmetric dimers formed in this way are interconnected by intermolecular C—H...π interactions with a rather short H...CgAdistance of 2.51 Å (CgAis the centroid of the central benzene ring). The molecules are arranged in regular parallel sheets. Within a sheet, molecules are interconnectedviaC—H...O interactions where all carbonyl O atoms participate in weak hydrogen bonds as hydrogen-bond acceptors. Neighbouring sheets are connected through the above-mentioned π–π and C—H...π interactions.
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Kim, Namhyung, Junwhan Ahn, Kiyoung Choi, Daniel Sanchez, Donghoon Yoo, and Soojung Ryu. "Benzene." ACM Transactions on Architecture and Code Optimization 15, no. 1 (April 2, 2018): 1–23. http://dx.doi.org/10.1145/3177963.
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Young, Jay A. "Benzene." Journal of Chemical Education 82, no. 12 (December 2005): 1769. http://dx.doi.org/10.1021/ed082p1769.
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Luttrell, William E., and Nicholas L. Conley. "Benzene." Journal of Chemical Health and Safety 18, no. 4 (July 2011): 32–33. http://dx.doi.org/10.1016/j.jchas.2011.05.005.
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Mbuvi, Harun M., and L. Keith Woo. "Addition of carbenes derived from aryldiazoacetates to arenes using chloro(tetraphenylporphyrinato)iron as catalyst." Journal of Porphyrins and Phthalocyanines 13, no. 01 (January 2009): 136–52. http://dx.doi.org/10.1142/s1088424609000036.
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Chloro(tetraphenylporphyrinato)iron, Fe ( TPP ) Cl , is an active catalyst for the Büchner addition of para-substituted methyl 2-phenyldiazoacetates, 1a–d, to substituted benzenes. Yields greater than 70% have been achieved at temperatures ranging from 60–100°C. Reactions of substituted methyl 2-phenyldiazoacetates with benzene gave rapidly equilibrating mixtures of norcaradienecycloheptatriene valence isomers, 2a–d/2′a–d, in yields over 70%. Treatment of chlorobenzene with methyl 2-phenyldiazoacetate produced a regio-isomeric mixture of 7-carbomethoxy-2-chloro-7-phenylnorcaradiene/7-carbomethoxy-2-chloro-7-phenylcycloheptatriene, 3a/3′a, and 7-carbomethoxy-3-chloro-7-phenylnorcaradiene/7-carbomethoxy-3-chloro-7-phenylcycloheptatriene, 4a/4′a. When p-methylanisole was treated with methyl 2-phenyldiazoacetate at 80°C, a product that largely favored a fused cyclopropane structure, 7-carbomethoxy-2-methoxy-5-methyl-7-phenylnorcaradiene, 12a, was obtained along with the benzylic C–H insertion product methyl 3-(p-methoxyphenyl)-2-phenylpropionate, 13a. Heating the norcaradiene product 12a at 110°C yielded the ring-opened diarylacetate, 14a. The diene forms of the fluxional norcaradiene-cycloheptatriene systems were trapped with benzyne to give one stereoisomer of 3,3-disubstituted benzhomobarralenes, 18a–d. The norcaradiene-cycloheptatriene valence isomers were quantitatively converted into ring-opened diaryl acetate products upon acidification in acetonitrile. Rates for the addition of methyl (p-chlorophenyl)diazoacetate to benzene were first order with respect to the diazo reagent. A concerted mechanism involing an iron carbene complex is proposed for these iron porphyrin-catalyzed Büchner reactions.