129-00-0

Basic information

• Product Name: Pyrene
• Synonyms: Pyrene (purity);Pyrenepract;PYRENE, FOR FLUORESCENCE;PYRENE, 1X1ML, CH2CL2, 200UG/ML;41164, Pyrene (purity);PYRENE, 5000MG, NEAT;PYRENE-D10, 25MG, NEAT;PYRENE, 1X1ML, MEOH, 1000UG/ML
• CAS NO: 129-00-0
• Molecular Formula: C₁₆H₁₀
• Molecular Weight: 202.25
• EINECS: 204-927-3
• Product Categories: Aromatic Compounds;Organics;Pyrenes;PAH
• Mol File: 129-00-0.mol
• Article Data: 140

Chemical Properties

• Melting Point: 148 °C
• Boiling Point: 393 °C
• Flash Point: 210 °C
• Appearance: Pale yellow to yellow-greenish/crystalline
• Density: 1.271
• Vapor Pressure: 2.28E-06mmHg at 25°C
• Refractive Index: 1.8520 (estimate)
• Storage Temp.: APPROX 4°C
• Solubility: ethanol: soluble
• PKA: >15 (Christensen et al., 1975)
• Water Solubility: almost insoluble
• Merck: 14,7963
• BRN: 1307225
• CAS DataBase Reference: Pyrene(CAS DataBase Reference)
• NIST Chemistry Reference: Pyrene(129-00-0)
• EPA Substance Registry System: Pyrene(129-00-0)

Safety Data

• Hazard Codes: N,T+,T,F,Xn
• Statements: 50/53-36/37/38-26-39/23/24/25-23/24/25-11-63-43-45-67-65-38-51/53-52/53-40
• Safety Statements: 60-61-45-36/37-28A-22-16-7-24/25-23-53-62-26
• RIDADR: UN 3077 9/PG 3
• WGK Germany: 2
• RTECS: UR2450000
• TSCA: Yes
• HazardClass: 6.1(b)
• PackingGroup: III
• Hazardous Substances Data: 129-00-0(Hazardous Substances Data)

Usage

Coal-tar chemical industrial products

Pyrene is one of the processing products of coal tar with the content in the coal tar being about 0.6 to 1.2% and is mainly concentrated in the anthracene oil fraction. Pyrene is a kind of solid aromatic compound with its molecule comprising of four benzene rings connected with each other. Pyrene has its molecular formula of C16H10, molecular weight of 202.26, melting point of 150 °C, boiling point of 393 °C and the density of 1.277g/cm3. Pyrene appears as pale yellow crystalline monoclinic tablets, insoluble in water and easily soluble in benzene, toluene, carbon disulfide, ether and other organic solvents. Pyrene is carcinogenic and can be converted to mutagenic 1-nitro-pyrene under the effect of nitrogen dioxide. The position 1 and position 6 of pyrene can easily react with electrophilic reagent as well as have oxidation and hydrogenation reaction. Pyrene can also have halogenation, nitration and sulfonation; mono-substitution occurs at the 3-position, di-substitution includes 3, 10 and 3, 8-position with 3, 10 being more frequent. Its oxidation can generate 3, 10-quinones and 3, 8-quinones which can further oxidized to generate 1, 4, 5, 8-naphthalene tetracarboxylic acid. Pyrene can be used in the production of dyes such as indanthrone dyes and anthraquinone vat dyes. The extraction method of is: take the residuum or bitumen distillate oil produced from the distillation of the anthracene fractions as the raw material, perform distillation under reduced pressure, take the 390~400 ℃ fraction which contains about 40% of pyrene fraction, then use 25% of the coal tar solvent oil and 75% ethanol mixed solvent (the volume of the solvent: pyrene fraction: 1:12), and recrystallized for several times until qualified products are obtained. Pyrene belongs to low toxicity compounds and has mild irritation effect on the skin, eyes and upper respiratory tract. Long-term inhalation can cause aglobulism and mild liver and kidney damage. Long-term exposure upon 3mg/m3~5mg/m3 can cause headaches, fatigue, loss of appetite, and being prone to excitable. The above information is edited by the lookchem of Dai Xiongfeng.

Probing agent for determination of the fluidity of membrane lipid

Pyrene is a commonly used probe for determination of the fluidity of the membrane lipid with high quantum yield but shorter excited lifetime than DPH (1, 6-diphenyl a 1, 3, 5-triene), so it is not sensitive enough for determination of the slight change in the lipid fluidity and is suitable for system of greater mobility. The excitation wavelength of pyrene is 342nm and the emission wavelength is 383nm with the excitation and emission spectra overlapping significantly with each other. Pyrene mainly bound to the hydrocarbon chain of the membrane lipid. Once a monomer formed via the binding between a pyrene molecule to lipid molecule had been excited by light, it move and be close to another pyrene molecule which has not been excited yet via lateral diffusion motion, forming collision compounds namely excitation dimer. The efficiency for the formation of the excitation dimer depends on the concentration of pyrene binding to the membrane lipid as well as the viscosity of the medium surrounding the pyrene. When the concentration and temperature of pyrene becomes stable, the ratio of the fluorescence intensity between monomer and dimer will decrease with the increasing viscosity of the medium surrounding the pyrene, namely pyrene, based on the ratio of the fluorescence of dimer to monomer, can reflect the lateral diffusion rate of the lipid molecule. High medium viscosity will cause small lateral diffusion rate and small liquidity. Reference: Editor: Huishan Liu, Binxue Liu & Zedai Fang; Reviwer: Shuyun Xu & Chuanggeng Ma; English-Chinese dictionary of pharmacology.

Chemical Properties

Different sources of media describe the Chemical Properties of 129-00-0 differently. You can refer to the following data:
1. It appears as light yellow monoclinic crystal. It is insoluble in water, easily soluble in ether, carbon disulfide, benzene and toluene.
2. pale yellow to yellow-greenish crystals or chunks
3. Pyrene is a colorless crystalline solid when pure or pale yellow plates (impure). Polycyclic aromatic hydrocarbons (PAHs) are compounds containing multiple benzene rings and are also called polynuclear aromatic hydrocarbons. Solids and solutions have a Blue fluores- cence (Merck Index).

Uses

Different sources of media describe the Uses of 129-00-0 differently. You can refer to the following data:
1. It can be used as raw material of organic synthesis. For example, it can be used for production of 1, 4, 5, 8-naphthalene tetracarboxylic acid via oxidation. It can be applied to dyes, synthetic resins and plastics; it can also be used for the manufacturing of vat dye Brilliant Orange GR and various kinds of other dyes. Moreover, it can also be used for the manufacturing of pesticides and plasticizers.
2. Pyrene occurs in coal tar. Also obtained by the destructive hydrogenation of hard coal. Found in wastewater in aquatic environments, and possesses genotoxic characteristics relating to estrogenic/andr ogenic, antiestrogenic and antiandrogenic activity.
3. Pyrene and its derivatives are used commercially to make?dyes?and dye precursors, for example?pyranine?and naphthalene-1,4,5,8-tetracarboxylic acid. It is used as a probe to determine solvent environments and fluorescence spectroscopy.
4. Pyrene may be used as an analytical reference standard for the quantification of the analyte in environmental tobacco smoke samples using high-performance liquid chromatography technique.

Production method

Pyrene is mainly presented in the distillates of coal tar pitch. Send the asphalt for vacuum distillation under medium temperature; at the same time, directly send a small amount of the overheated steam to the distillation vessel; take the narrow fraction of pyrene and then use the mixed solution of solvent oil and ethanol or a mixed solution of benzene and solvent oil for recrystallization to obtain industrial pyrene with purity of 95%.

Description

Pyrene is an organic compound with chemical formula C16H10, light yellow monoclinic crystal (pure product is colorless), aromatic, combustible[1], insoluble in water and soluble in ethanol and ether. It can carry out electrophilic substitution, such as halogenation, nitration, sulfonation and other reactions. Pyrene mainly exists in the distillate of coal tar pitch. Pyrene is an organic synthetic raw material, which can be oxidized to produce 1,4,5,8-naphthalene tetracarboxylic acid, which is used in dyes, synthetic resins, disperse dyes and engineering plastics; After acylation, the vat dye brilliant orange GR and other dyes can be prepared. It can also make pesticides, plasticizers, etc. On October 27, 2017, the list of carcinogens published by the international agency for research on cancer of the World Health Organization was preliminarily sorted out for reference. Pyrene was included in the list of three types of carcinogens.

Physical properties

Colorless solid (tetracene impurities impart a yellow color) or monoclinic prisms crystallized from alcohol. Solutions have a slight blue fluorescence.

Production Methods

There is no commercial production or known use for this compound. Pyrene has been used as starting material for the synthesis of benzo[a]pyrene.

Definition

Different sources of media describe the Definition of 129-00-0 differently. You can refer to the following data:
1. A condensed ring hydro- carbon.
2. A solid aromatic compound whose molecules consist of four benzene rings joined together. It is carcinogenic.

General Description

Colorless solid, solid and solutions have a slight blue fluorescence. Used in biochemical research.

Air & Water Reactions

Insoluble in water.

Reactivity Profile

Pyrene reacts with nitrogen oxides to form nitro derivatives. Pyrene also reacts with 70% nitric acid.

Hazard

A questionable carcinogen, absorbed by skin.

Health Hazard

Different sources of media describe the Health Hazard of 129-00-0 differently. You can refer to the following data:
1. Pyrene is a carcinogenic agent and is absorbed by the skin. It is a skin irritant, a suspected mutagen, and an equivocal tumor-causing agent. Workers exposed to 3 to 5 mg/m3 of Pyrene exhibited some teratogenic effects. Pyrene is a polycyclic aromatic hydrocarbon (PAH). The acute toxicity of pure PAHs appears low when administered orally or dermally to rats or mice. Human exposure to PAHs is almost exclusively via the gastrointestinal and respiratory tracts, and approximately 99 percent is ingested in the diet. Despite the high concentrations of Pyrene to which humans may be exposed through food, there is currently little information available to implicate diet-derived PAHs as the cause of serious health effects.
2. Inhalation of its vapors or ingestion causedirritation of the eyes, excitement, and musclecontraction in rats and mice. An oral LD50value in mice has been reported as 800 mg/kg.Studies on experimental animals do not giveevidence of carcinogenicity. Skin tumors,however, have been reported in mice (NIOSH1986). Pyrene tested negative to a histidinereversion–Ames test and other mutagenictests.

Fire Hazard

When heated to decomposition, Pyrene emits acrid smoke and fumes.

Safety Profile

Poison by inhalation. Moderately toxic by ingestion and intraperitoneal routes. A sh irritant. Questionable carcinogen with experimental tumorigenic data. Human mutation data reported. When heated to decomposition it emits acrid smoke and irritating fumes.

Synthesis

The content in high temperature tar is about 1.2% ~ 1.8%, which is prepared by separation and purification. Using anthracene oil as raw material, vacuum distillation, extraction, recrystallization and purification. The residue of distilled anthracene oil above 360 ℃ is used as raw material, the pyrene fraction is cut by distillation, benzene is used as solvent, washed with concentrated sulfuric acid, the base and unsaturated compounds are removed, and then the pure product is recrystallized with solvent oil. It can also be extracted from tobacco. Pyrene mainly exists in the distillate of coal tar pitch. The medium temperature asphalt is distilled under reduced pressure, and a small amount of direct superheated steam is introduced into the distillation kettle to cut the narrow fraction of pyrene, and then recrystallized with the mixed solution of solvent oil and ethanol or the mixed solution of benzene and solvent oil to obtain industrial pyrene with a purity of 95%.

Potential Exposure

Pyrene is used as an industrial chemi- cal and in biochemical research.

Carcinogenicity

Pyrene was inactive as a tumor initiator. Based on inadequate animal data and no human data, the IARC classified pyrene as group 3, not classifiable as to its carcinogenicity to humans, and IRIS classified pyrene as a class D compound. Pyrene is present as a major component of the total content of PAHs in the environment. Exposure occurs primarily through tobacco smoke, inhalation of polluted air, and by ingestion of food and water.

Source

Detected in groundwater beneath a former coal gasification plant in Seattle, WA at a concentration of 180 μg/L (ASTR, 1995). Detected in 8 diesel fuels at concentrations ranging from 0.16 to 24 mg/L with a mean value of 5.54 mg/L (Westerholm and Li, 1994). Identified in Kuwait and South Louisiana crude oils at concentrations of 4.5 and 3.5 ppm, respectively (Pancirov and Brown, 1975). Based on laboratory analysis of 7 coal tar samples, pyrene concentrations ranged from 900 to 18,000 ppm (EPRI, 1990). Detected in 1-yr aged coal tar film and bulk coal tar at concentrations of 2,700 and 2,900 mg/kg, respectively (Nelson et al., 1996). Lehmann et al. (1984) reported a pyrene concentration of 125 mg/g in a commercial anthracene oil. Identified in high-temperature coal tar pitches used in electrodes at concentrations ranging from 4,500 to 34,900 mg/kg (Arrendale and Rogers, 1981). Lee et al. (1992a) equilibrated eight coal tars with distilled water at 25 °C. The maximum concentration pyrene observed in the aqueous phase is 0.1 mg/L. Nine commercially available creosote samples contained pyrene at concentrations ranging from 31,000 to 100,000 mg/kg (Kohler et al., 2000). Also detected in asphalt fumes at an average concentration of 140.21 ng/m3 (Wang et al., 2001). Schauer et al. (1999) reported pyrene in diesel fuel at a concentration of 64 μg/g and in a dieselpowered medium-duty truck exhaust at an emission rate of 71.9 μg/km. California Phase II reformulated gasoline contained pyrene at a concentration of 3.38 g/kg. Gasphase tailpipe emission rates from gasoline-powered automobiles with and without catalytic converters were approximately 4.28 and 160 μg/km, respectively (Schauer et al., 2002). Schauer et al. (2001) measured organic compound emission rates for volatile organic compounds, gas-phase semi-volatile organic compounds, and particle-phase organic compounds from the residential (fireplace) combustion of pine, oak, and eucalyptus. The respective gas-phase and particle-phase emission rates of pyrene were 1.87 and 3.78 mg/kg of pine burned, 2.40 and 1.23 mg/kg of oak burned, and 2.70 and 0.585 mg/kg of eucalyptus burned. Under atmospheric conditions, a low rank coal (0.5–1 mm particle size) from Spain was burned in a fluidized bed reactor at seven different temperatures (50 °C increments) beginning at 650 °C. The combustion experiment was also conducted at different amounts of excess oxygen (5 to 40%) and different flow rates (700 to 1,100 L/h). At 20% excess oxygen and a flow rate of 860 L/h, the amount of pyrene emitted ranged from 29.9 ng/kg at 700 °C to 402.9 ng/kg at 750 °C. The greatest amount of PAHs emitted were observed at 750 °C (Mastral et al., 1999). Drinking water standard: No MCLGs or MCLs have been proposed by the U.S. EPA (2000).

Environmental fate

Biological. When pyrene was statically incubated in the dark at 25 °C with yeast extract and settled domestic wastewater inoculum, complete degradation was demonstrated at the 5 mg/L substrate concentration after 2 wk. At a substrate concentration of 10 mg/L, however, only 11 and 2% losses were observed after 7 and 14 d, respectively (Tabak et al., 1981). Soil. The reported half-lives for pyrene in a Kidman sandy loam and McLaurin sandy loam are 260 and 199 d, respectively (Park et al., 1990). Plant. Hückelhoven et al. (1997) studied the metabolism of pyrene by suspended plant cell cultures of soybean, wheat, jimsonweed, and purple foxglove. Soluble metabolites were only detected in foxglove and wheat. Approximately 90% of pyrene was transformed in wheat. In foxglove, 1-hydroxypyrene methyl ether was identified as the main metabolite but in wheat, the metabolites were identified as conjugates of 1-hydroxypyrene. Photolytic. Adsorption onto garden soil for 10 d at 32 °C and irradiated with UV light produced 1,1′- bipyrene, 1,6-pyrenedione, 1,8-pyrenedione, and three unidentified compounds (Fatiadi, 1967). Microbial degradation by Mycobacterium sp. yielded the following ring-fission products: 4-phenanthroic acid, 4-hydroxyperinaphthenone, cinnamic acid, and phthalic acid. The compounds pyrenol and the cis- and trans-4,5-dihydrodiols of pyrene were identified as ring-oxidation products (Heitkamp et al., 1988). Chemical/Physical. At room temperature, concentrated sulfuric acid will react with pyrene to form a mixture of disulfonic acids. In addition, an atmosphere containing 10% sulfur dioxide transformed pyrene into many sulfur compounds, including pyrene-1-sulfonic acid and pyrenedisulfonic acid (Nielsen et al., 1983).

Shipping

UN3077 Environmentally hazardous substances, solid, n.o.s., Hazard class: 9; Labels: 9-Miscellaneous haz- ardous material, Technical Name Required.

Purification Methods

Crystallise pyrene from EtOH, glacial acetic acid, *benzene or toluene. Purify it also by chromatography of CCl4 solutions on alumina, with *benzene or n-hexane as eluent. [Backer & Whitten J Phys Chem 91 865 1987.] It can also be zone refined and purified by sublimation. Marvel and Anderson [J Am Chem Soc 76 5434 1954] refluxed pyrene (35g) in toluene (400mL) with maleic anhydride (5g) for 4days, then added 150mL of aqueous 5% KOH and refluxed for 5hours with occasional shaking. The toluene layer was separated, washed thoroughly with H2O, concentrated to about 100mL and allowed to cool. Crystalline pyrene was filtered off and recrystallised three times from EtOH or acetonitrile. [Chu & Thomas J Am Chem Soc 108 6270 1986, Russell et al. Anal Chem 50 2961 1986.] The material is free from anthracene derivatives. Another purification step involves passage of pyrene in cyclohexane through a column of silica gel. It can be sublimed in a vacuum and zone refined. The picrate has m 224o. [Kano et al. J Phys Chem 89 3748 1985, Beilstein 5 IV 2467.]

Incompatibilities

Pyrene Dust may form explosive mixture with air. Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides. Pyrene reacts with nitrogen oxides to form nitro derivatives. It also reacts with 70% nitric acid

Waste Disposal

Dissolve or mix the material with a combustible solvent and burn in a chemical incinerator equipped with an afterburner and scrubber. All federal, state, and local environmental regulations must be observed .

InChI:InChI=1/C16H10/c1-3-11-7-9-13-5-2-6-14-10-8-12(4-1)15(11)16(13)14/h1-10H

Synthetic route

4-ethynyl-phenanthrene (69320-05-4) → pyrene (129-00-0)

Conditions	Yield
at 800℃; under 0.01 Torr; Product distribution; other temperatures;	100%

4,5,9,10-tetrahydropyrene (781-17-9) → pyrene (129-00-0)

Conditions	Yield
With 2,3-dicyano-5,6-dichloro-p-benzoquinone In benzene for 4h; Heating;	98%
With 2,3-dicyano-5,6-dichloro-p-benzoquinone In benzene for 48h; Ambient temperature;	80%
With triphenylmethyl perchlorate; acetic acid

1-bromopyrene (1714-29-0) → pyrene (129-00-0)

Conditions	Yield
With triethylamine In methanol; water at 4℃; for 0.25h; Irradiation; sensitizer: methylene blue;	98%
With tetraethylammonium perchlorate; triethylamine In ethanol; dimethyl sulfoxide at 20℃; for 12h; Electrolysis; Green chemistry;	92%
With tetrabutylammonium perchlorate In N,N-dimethyl-formamide at 22℃; Mechanism; electroreduction at Hg electrode, Pt counter electrode, current oscillations, other temperatures;
Multi-step reaction with 2 steps 1.1: n-butyllithium / tetrahydrofuran / 3 h / -78 °C 1.2: -78 - 20 °C 1.3: 1 h 2.1: caesium carbonate / 1-methyl-pyrrolidin-2-one; water / 10 h / 100 °C View Scheme

8-methoxy[2.2]metaparacyclophane-1,9-diene → pyrene (129-00-0)

Conditions	Yield
With titanium tetrachloride In dichloromethane at 0℃; for 0.0166667h;	95%

pyrene-1-aldehyde (3029-19-4) → pyrene (129-00-0)

Conditions	Yield
With palladium diacetate In cyclohexane at 140℃; for 24h; Molecular sieve; air;	95%
With palladium diacetate; potassium carbonate In ethyl acetate at 150℃; under 12929 Torr; for 0.833333h; Microwave irradiation; Molecular sieve;	95%

1-pyrenediazonium tetrafluoroborate → pyrene (129-00-0)

Conditions	Yield
With chloro-trimethyl-silane In tetrahydrofuran; N,N-dimethyl-formamide at 60℃; for 1h;	91%

2,7-di-tertbutylpyrene (24300-91-2) → pyrene (129-00-0)

Conditions	Yield
With Nafion-H In toluene for 24h; Heating;	90%

C17H15S2(1+)*BF4(1-) → pyrene (129-00-0)

Conditions	Yield
With potassium tert-butylate at -80℃;	90%
With potassium tert-butylate at -80℃; Mechanism; reaction with other sulfonium salt was investigated;	90%

1-pyrenemethanol (24463-15-8) → pyrene (129-00-0)

Conditions	Yield
With oxygen; palladium diacetate; sodium carbonate at 130℃; for 36h; Molecular sieve; Schlenk technique;	88%

4-bromopyrene (1732-26-9) → pyrene (129-00-0)

Conditions	Yield
With 4-methyl-morpholine; tetrahydroxydiboron; 5%-palladium/activated carbon In 1,2-dichloro-ethane at 50℃; for 3h;	86%

[2.2]Metacyclophan (51744-98-0, 2319-97-3, 96290-39-0) → pyrene (129-00-0) + 4,5-dihydropyrene (6628-98-4) + 4,5,9,10-tetrahydropyrene (781-17-9) + 1,2,3,3a,4,5,9,10-octahydropyrene (55775-16-1) + 1,2,3,3a,4,5-hexahydropyrene (5385-37-5) + 1,2,3,3a,4,5,9,10,10a,10b-decahydropyrene (53076-44-1, 55781-65-2, 55821-21-1, 102339-92-4, 126188-30-5)

Conditions	Yield
With hydrogenchloride; aluminium trichloride In carbon disulfide Product distribution; Heating;	A 3% B n/a C n/a D 12% E 84% F 1%

[2.2]Metacyclophan (51744-98-0, 2319-97-3, 96290-39-0) → pyrene (129-00-0) + 1,2,3,3a,4,5,9,10-octahydropyrene (55775-16-1) + 1,2,3,3a,4,5-hexahydropyrene (5385-37-5) + 1,2,3,3a,4,5,9,10,10a,10b-decahydropyrene (53076-44-1, 55781-65-2, 55821-21-1, 102339-92-4, 126188-30-5)

Conditions	Yield
With hydrogenchloride; aluminium trichloride In carbon disulfide Heating;	A 3% B 12% C 84% D 1%

C20H12N2O → pyrene (129-00-0)

Conditions	Yield
With bis(1,5-cyclooctadiene)nickel (0); ethyl-diphenyl-phosphane In toluene at 130℃; for 24h; Inert atmosphere;	84%
With bis(1,5-cyclooctadiene)nickel (0); 1,1,3,3-Tetramethyldisiloxane; ethyl-diphenyl-phosphane In toluene at 130℃; Inert atmosphere;	84%

4,4,5,5-tetramethyl-2-(pyren-4-yl)-1,3,2-dioxaborolane + N-(2,6-diisopropylphenyl)-4,5-dibromonaphthalene-1,8-dicarboximide (1246857-77-1) → pyrene (129-00-0) + C56H39NO2

Conditions	Yield
With dicyclohexyl-(2',6'-dimethoxybiphenyl-2-yl)-phosphane; caesium carbonate; bis(dibenzylideneacetone)-palladium(0) In water; toluene at 90℃; Suzuki-Miyaura Coupling;	A 76% B n/a

2,7-Di-tert-butyl-4-propyl-pyrene (129332-99-6) → pyrene (129-00-0) + 4-propyl-pyrene (74869-50-4)

Conditions	Yield
With Nafion-H In toluene for 24h; Heating;	A 8% B 72%

(E)-5-styrylphenanthrene-4-carbaldehyde → pyrene (129-00-0)

Conditions	Yield
With iron(III) chloride In 1,2-dichloro-ethane at 20℃; for 0.5h; regioselective reaction;	70%

diphenyl(1-pyrenyl)phosphorus oxide → pyrene (129-00-0) + diphenyl(pyren-2-yl)phosphine oxide

Conditions	Yield
With aluminum (III) chloride; sodium chloride at 160℃; for 1h; Temperature; Schlenk technique; Inert atmosphere; regioselective reaction;	A 7% B 70%

anti-8-fluoro-16-methyl-10-methylsulfanyl<22>metacyclophane-1-ene → pyrene (129-00-0) + 8-fluoro-16-methyl<22>metacyclophane

Conditions	Yield
With W-7 Raney Nickel In ethanol for 14h; Heating;	A 19% B 63%

1-chloropyrene (34244-14-9) → pyrene (129-00-0) + 4,5-dihydropyrene (6628-98-4)

Conditions	Yield
With sodium methylate In methanol for 3h; Irradiation;	A 57% B 31%

α,α,α',α'-tetrabromo-m-xylene (36323-28-1) → pyrene (129-00-0)

Conditions	Yield
With magnesium at 600℃;	54%

N-(2,6-diisopropylphenyl)-4,5-dibromonaphthalene-1,8-dicarboximide (1246857-77-1) + 1-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyrene (349666-24-6) → pyrene (129-00-0) + C56H39NO2 + N-(2,6-diisopropylphenyl)naphtho[8,1,2-bcd]perylene-9,10-dicarboximide

Conditions	Yield
With dicyclohexyl-(2',6'-dimethoxybiphenyl-2-yl)-phosphane; caesium carbonate; bis(dibenzylideneacetone)-palladium(0) In water; toluene at 90℃; Solvent; Reagent/catalyst; Suzuki-Miyaura Coupling;	A 50% B n/a C 50%

azupyrene (193-85-1) → pyrene (129-00-0)

Conditions	Yield
at 450 - 460℃; Mechanism; 5-6 h;	45%
at 500 - 510℃; under 0.0001 Torr; for 1h; Product distribution;	40%

2,6-bis[(trimethylsilyl)ethynyl]biphenyl (1293326-45-0) → pyrene (129-00-0)

Conditions	Yield
With [(t-BuXPhos)Au]NTf2 In para-xylene at 150℃; for 24h;	42%
Multi-step reaction with 2 steps 1: potassium carbonate / methanol / 20 °C 2: [(t-BuXPhos)Au]NTf2 / 1,2-dichloro-ethane / 24 h / 80 °C View Scheme

phenyldi(pyren-1-yl)phosphine oxide → pyrene (129-00-0) + phenyldi(pyren-2-yl)phosphine oxide

Conditions	Yield
With aluminum (III) chloride; sodium chloride at 160℃; for 1h; Schlenk technique; Inert atmosphere; regioselective reaction;	A 35% B 12%

2,6-diethynylbiphenyl (1293326-48-3) → pyrene (129-00-0)

Conditions	Yield
With [(t-BuXPhos)Au]NTf2 In 1,2-dichloro-ethane at 80℃; for 24h;	30%

3-(1-pyrenyl)propionic acid (61098-93-9) → pyrene (129-00-0) + 6H-benzopyrene (191-33-3) + 5-oxo-5H-benzo[cd]pyrene (4558-16-1) + naphthanthrone (3074-00-8) + 6H-benzo[cd]pyren-6-ol + 4,5-dihydro-3H-benzo[cd]pyrene (7130-15-6) + 7,8-dihydro-9H-cyclopentapyrene (82979-72-4)

Conditions	Yield
With polyphosphoric acid at 80℃; for 24h; Inert atmosphere;	A n/a B 26% C 30% D 29% E n/a F n/a G n/a

3-(4H-cyclopentaphenanthrylidene)-1,5-bis(trimethylsilyl)-1,4-pentadiyne (157729-37-8) → pyrene (129-00-0) + benzo[e]pyrene (192-97-2) + 4H-Cyclopenta[def]phenanthrene (203-64-5) + cyclopenta[c,d]pyrene (27208-37-3) + benzo[ghi]fluoranthene (203-12-3) + Coarannulen (5821-51-2)

Conditions	Yield
With hydrogen In gas at 900℃; Product distribution; electrically heated vertical laboratory tubular furnace;	A n/a B n/a C n/a D n/a E n/a F 15%

3-(4H-cyclopentaphenanthrylidene)-1,5-bis(trimethylsilyl)-1,4-pentadiyne (157729-37-8) → pyrene (129-00-0) + benzo[e]pyrene (192-97-2) + cyclopenta[c,d]pyrene (27208-37-3) + Coarannulen (5821-51-2)

Conditions	Yield
With hydrogen In gas at 900℃; electrically heated vertical laboratory tubular furnace; Further byproducts given;	A n/a B n/a C n/a D 15%

4,5-epoxy-4,5-dihydro-pyrene (37496-00-7) → pyrene (129-00-0)

Conditions	Yield
With tetraphenylporphinatoiron(II)(pyridine)2 for 30h; Ambient temperature;	12%

(E,E)-1,3-distyrylbenzene (1725-76-4) → pyrene (129-00-0) + benzo[c]chrysene (194-69-4) + (1α,2α,3β,4β)-1,3-Di-2-phenanthryl-2,4-diphenylcyclobutan (100603-86-9) + (1α,2α,3β,4β)-1,2-Di-2-phenanthryl-3,4-diphenylcyclobutan (100603-85-8) + 3,4,12,13-Tetraphenylpentacyclo<13.3.1.16,10.02,5.011,14>eicosa-1(19),6,8,10(20),15,17-hexaen (100758-80-3) + 3b,4,5,5a,8b,9,10,10a-Octahydro-4,5,9,10-tetraphenyldicyclobutapyren (100603-84-7) + phenanthrene, stilbenes, cyclobutapyrene

Conditions	Yield
With iodine In benzene for 1.5h; Product distribution; Mechanism; Irradiation; further without I2, var. conc.;	A 3% B 7% C 7% D 7% E n/a F n/a G n/a

pyrene (129-00-0) → 1-bromopyrene (1714-29-0)

Conditions	Yield
With N-Bromosuccinimide In dichloromethane for 2h;	100%
With hydrogen bromide; dihydrogen peroxide In methanol; diethyl ether; water at 15 - 20℃; for 12.25h;	96%
With N-Bromosuccinimide; dibenzoyl peroxide In N,N-dimethyl-formamide at 20℃;	96%

pyrene (129-00-0) + acetyl chloride (75-36-5) → 1-acetylpyrene (3264-21-9)

Conditions	Yield
With aluminum (III) chloride In dichloromethane at 0 - 20℃; Friedel-Crafts Acylation; Inert atmosphere;	100%
With aluminum (III) chloride In 1,2-dichloro-ethane at 20℃; for 24h;	98.3%
With aluminum (III) chloride In dichloromethane at 25℃; for 0.5h;	98.4%

pyrene (129-00-0) + tertiary butyl chloride (507-20-0) → 2-(tert-butyl)pyrene (78751-62-9)

Conditions	Yield
With aluminum (III) chloride In dichloromethane at 0 - 20℃; for 3h; Inert atmosphere;	100%
With aluminum tri-bromide In carbon disulfide at 40℃; for 0.5h;	99%
aluminium trichloride In carbon disulfide Heating;	99%

pyrene (129-00-0) + 11-bromoundecanoyl chloride (15949-84-5) → 11-bromo-1-(pyren-1-yl)undecan-1-one (72185-41-2)

Conditions	Yield
Stage #1: 11-bromoundecanoyl chloride With aluminum (III) chloride In dichloromethane Stage #2: pyrene In dichloromethane at 0 - 20℃; for 16.5h;	100%
With aluminium trichloride In dichloromethane at 0℃; for 3h;	80%

pyrene (129-00-0) + (ethylenediamine palladium(II))6(2,4,6-tris(4-pyridyl)triazine)4(NO3)12 + decalin (91-17-8) → [(Pd(H2NC2H4NH2))6((NC5H4)3C3N3)4](12+)*12NO3(1-)*C16H10*C10H18=[(Pd(C2H8N2))6((NC5H4)3C3N3)4](NO3)12(C10H18)(C16H10)

Conditions	Yield
In water-d2 Pd complex was treated with decalin and pyrene in D2O at room temp.; NMR monitoring;	100%

pyrene (129-00-0) → 2,6-dibromo-1,4,5,8-naphthalenetetracarboxylic acid dianhydride (83204-68-6)

Conditions	Yield
With sulfuric acid	100%

pyrene (129-00-0) + 4C28H16N2*4C18H8O4(2-)*8C10H14*8Ru(2+)*8CF3O3S(1-)*12H2O → 2C28H16N2*2C18H8O4(2-)*4C10H14*4Ru(2+)*7C16H10*4CF3O3S(1-)

Conditions	Yield
In methanol at 40℃; for 2h; Sealed tube;	100%

pyrene (129-00-0) + 2-Methoxybenzoyl chloride (21615-34-9) → (2-methoxyphenyl)pyren-1-ylmethanone

Conditions	Yield
With aluminum (III) chloride at 20℃; for 6h;	100%
With aluminum (III) chloride In dichloromethane at 0 - 20℃; for 1.16667h;	95%

pyrene (129-00-0) + 4C6H2O4(2-)*4C14H8N4S2*8C10H15(1-)*8CF3O3S(1-)*8Rh(3+) → C80H80N8O8Rh4S4(4+)*4CF3O3S(1-)*3C16H10

Conditions	Yield
In methanol at 20℃; for 24h;	100%

pyrene (129-00-0) + 4C6H2O4(2-)*4C14H8N4S2*8C10H15(1-)*8CF3O3S(1-)*8Ir(3+) → C80H80Ir4N8O8S4(4+)*4CF3O3S(1-)*3C16H10

Conditions	Yield
In methanol at 20℃; for 24h;	100%

pyrene (129-00-0) + C80H80N8O8Rh4S4(4+)*4CF3O3S(1-) → C80H80N8O8Rh4S4(4+)*4CF3O3S(1-)*3C16H10

Conditions	Yield
In methanol at 20℃; for 24h;	100%

pyrene (129-00-0) + C80H80Ir4N8O8S4(4+)*4CF3O3S(1-) → C80H80Ir4N8O8S4(4+)*4CF3O3S(1-)*3C16H10

Conditions	Yield
In methanol at 20℃; for 24h;	100%

pyrene (129-00-0) + 16-bromohexadecanoyl chloride, (73782-15-7) → 16-bromo-1-(pyren-1-yl)-hexadecan-1-one

Conditions	Yield
Stage #1: 16-bromohexadecanoyl chloride, With aluminum (III) chloride In dichloromethane at 0℃; for 1h; Stage #2: pyrene In dichloromethane at 0 - 20℃; for 16h;	100%

pyrene (129-00-0) → 1-nitropyrene (5522-43-0)

Conditions	Yield
With nitric acid; acetic acid at 60℃; for 0.5h; Inert atmosphere; regioselective reaction;	99%
With ammonium persulfate; sodium nitrite In acetonitrile for 21h; Ambient temperature;	98%
With dinitrogen tetraoxide In dichloromethane for 0.5h; Ambient temperature;	97%

pyrene (129-00-0) → 1,3,6,8-tetrabromopyrene (128-63-2)

Conditions	Yield
With bromine In nitrobenzene at 120℃; for 2h;	99%
With bromine In nitrobenzene at 120℃; for 14h;	98%
With bromine In nitrobenzene at 120℃; Inert atmosphere;	98%

pyrene (129-00-0) + 2,4-dichloro-2,4-dimethylpentane (33553-93-4) → 7,7,9,9-tetramethyl-8,9-dihydro-7H-cyclopentapyrene

Conditions	Yield
aluminium trichloride In carbon disulfide for 1h; Heating;	99%

pyrene (129-00-0) + tertiary butyl chloride (507-20-0) → 2,7-di-tertbutylpyrene (24300-91-2) + 2-(tert-butyl)pyrene (78751-62-9)

Conditions	Yield
aluminium trichloride In carbon disulfide for 1h; Mechanism; Heating; various solvents;	A n/a B 99%
With aluminium trichloride In dichloromethane for 3h; Ambient temperature;	A n/a B 63%
With aluminum (III) chloride In dichloromethane at 0℃; for 3h; Inert atmosphere;	A 11% B 40%
With aluminium trichloride In dichloromethane for 3h; Ambient temperature; Yields of byproduct given;

pyrene (129-00-0) + 2,5-dichloro-2,5-dimethyl hexane (6223-78-5) → 7,7,10,10-tetramethyl-7,8,9,10-tetrahydrobenzopyrene

Conditions	Yield
aluminium trichloride In carbon disulfide for 1h; Heating;	99%

pyrene (129-00-0) + samarocene → {Sm(C5(CH3)5)2}2(C16H10)

Conditions	Yield
In toluene under N2 or Ar; pyrene was added to the samarocene in toluene, stirred for 5 min; solvent was removed by rotary evapn.; elem. anal.;	99%

phthalic anhydride (85-44-9) + pyrene (129-00-0) → 1-(o-carboxybenzoyl)pyrene (58926-23-1)

Conditions	Yield
Stage #1: phthalic anhydride; pyrene With aluminum (III) chloride In dichloromethane; water for 3h; Friedel-Crafts Acylation; Reflux; Inert atmosphere; Stage #2: With hydrogenchloride In dichloromethane; water Inert atmosphere;	98%
Stage #1: phthalic anhydride; pyrene With aluminum (III) chloride In dichloromethane for 3h; Inert atmosphere; Reflux; Stage #2: With acetic acid at 130℃; for 0.0833333h; Inert atmosphere;	87%
With aluminum (III) chloride In neat (no solvent) for 2h; Friedel-Crafts Acylation; Milling;	79%

pyrene (129-00-0) + C168H156N24Ru6(6+)*3CF3O3S(1-) → 2C16H10*C168H156N24Ru6(6+)*(x)CF3O3S(1-)

Conditions	Yield
In methanol at 20℃; for 2h; Inert atmosphere; Schlenk technique;	98%

pyrene (129-00-0) → 4,5,9,10-tetrahydropyrene (781-17-9)

Conditions	Yield
With hydrogen; 10percent Pd/C under 2327.23 Torr; for 144h;	97%
With palladium 10% on activated carbon; hydrogen In tetrahydrofuran; methanol at 90℃; under 7500.75 Torr; for 168h; Autoclave;	90%
Stage #1: pyrene With ethyl acetate at 20℃; for 48h; Inert atmosphere; Stage #2: With palladium 10% on activated carbon; hydrogen at 60℃; under 4500.45 Torr; for 48h; Inert atmosphere;	89%

pyrene (129-00-0) + bis(pinacol)diborane (73183-34-3) → 4,4,5,5-tetramethyl-2-[7-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyren-2-yl]-1,3,2-dioxaborolane

Conditions	Yield
With dtbpy; (1,5-cyclooctadiene)(methoxy)iridium(I) dimer In cyclohexane at 80℃; for 16h;	97%
With (1,5-cyclooctadiene)(methoxy)iridium(I) dimer; 4,4'-di-tert-butyl-2,2'-bipyridine In tetrahydrofuran at 80℃; for 16h; Inert atmosphere; regiospecific reaction;	94%
With (1,5-cyclooctadiene)(methoxy)iridium(I) dimer In tetrahydrofuran for 12h; Inert atmosphere; Reflux;	94%

pyrene (129-00-0) + bis(pinacol)diborane (73183-34-3) → 4,4,5,5-tetramethyl-2-pyren-2-yl-[1, 3, 2]dioxaborolane (853377-11-4)

Conditions	Yield
With catalyst:[Ir(OMe)COD]2/dtbpy In not given 2.2 molar equiv. of B2pin2, (Ir(OMe)COD)2 (5 mol%) + 4,4'-di-tert-butyl-2,2'-bipyridine (10 mol%); chromd. on silica pad (CH2Cl2); solvent removed (vac. 150°C); elem. anal.;	97%
With (1,5-cyclooctadiene)(methoxy)iridium(I) dimer; 4,4'-di-tert-butyl-2,2'-bipyridine In hexane at 80℃; for 16h; Inert atmosphere; regioselective reaction;	65%
With (1,5-cyclooctadiene)(methoxy)iridium(I) dimer; 4,4'-di-tert-butyl-2,2'-bipyridine In cyclohexene at 80℃; for 12h; Inert atmosphere;	65%

pyrene (129-00-0) + tertiary butyl chloride (507-20-0) → 2,7-di-tertbutylpyrene (24300-91-2)

Conditions	Yield
With aluminum tri-bromide In carbon disulfide at 40℃; for 1h;	96%
With aluminum (III) chloride In dichloromethane at 5 - 20℃; for 4h;	92%
With aluminum (III) chloride In dichloromethane at 5 - 20℃; for 4.5h; Inert atmosphere;	92%

pyrene (129-00-0) + Dichloromethyl methyl ether (4885-02-3) → pyrene-1-aldehyde (3029-19-4)

Conditions	Yield
With titanium tetrachloride In dichloromethane at 0 - 20℃; for 2.5h;	96%
With titanium tetrachloride In dichloromethane at 0 - 20℃; for 3h; Inert atmosphere;	91%
With titanium tetrachloride In dichloromethane for 3h; Ambient temperature;	90%

pyrene (129-00-0) → pyrene-d10 (1718-52-1)

Conditions	Yield
With [mesitylenium]B(C6F5)4; benzene-d6 In benzene-d6 at 70℃; for 72h; Inert atmosphere;	96%
With d7-N,N-dimethylformamide; potassium tert-butylate at 170℃; for 1h; Microwave irradiation;	95%
With water-d2; hydrogen chloride at 250℃; for 50h;	89%

Upstream product

• 51744-98-0 [2.2]Metacyclophan 
• 781-17-9 4,5,9,10-tetrahydropyrene 
• 13948-08-8 trityl cation 
• 1732-13-4 1,2,3,6,7,8-hexahydropyrene 
• 476-68-6 6-methoxy-4-(2-methylamino-ethyl)-phenanthrene-1,5-diol 
• 93010-33-4 4-ethyl-1,2-dihydro-phenanthrene 
• 7499-60-7 γ-oxo-1-pyrenebutyric acid 
• 5435-44-9 (E)-3-Ureido-but-2-enoic acid ethyl ester 
• 7463-36-7 Thebenol 
• 875235-66-8 2-ethyl-3',4'-dihydro-1'H-spiro[cyclopentane-1,2'-naphthalene] 
• 173604-18-7 pyrene-4,9-diol 
• 854241-57-9 biphenyl-2,6-diyldi-acetic acid 
• 108536-87-4 9-hydroxy-1-oxo-2,3,4,5-tetrahydro-1H-pyrene-3a-carboxylic acid ethyl ester 
• 74-86-2 acetylene 

Downstream Products

• 1714-29-0 1-bromopyrene 
• 42211-34-7 1-benzylpyrene 
• 188-89-6 2,3-peri-Naphthylen-pyren 
• 191-06-0 Dibenzonaphtho<2.1.8.7.6-tuvwx>hexaphen 
• 115209-69-3 (2,5-dimethyl-phenyl)-pyren-1-yl ketone 
• 102948-88-9 pyren-1-yl-(2,4,5-trimethyl-phenyl)-ketone 
• 3029-19-4 pyrene-1-aldehyde 
• 1691-65-2 1-fluoropyrene 
• 5101-26-8 1,1'-dipyrenyl 
• 34244-14-9 1-chloropyrene 
• 5522-43-0 1-nitropyrene 
• 1785-51-9 pyrene-1,6-dione 
• 2304-85-0 pyrene-1,8-dione 
• 27973-29-1 1,6-dibromopyrene 

Related news

Cover Picture: Photochemical Transformations Accelerated in Continuous‐Flow Reactors: Basic Concepts and Applications / Low‐LUMO Pyrene (cas 129-00-0)‐Fused Azaacenes / Synthesis, Characterization, and Metal Ion Coordination of a Multichromophoric Highly Luminescent Polysulfurated Pyrene (cas 129-00-0) / Indirect Photochemistry in Sunlit Surface Waters: Photoinduced Production of Reactive Transient Species / Carbon Monoxide‐Induced Dynamic Metal‐Surface Nanostructuring / Biomimetic Synthesis of (+)‐Ledene, (+)‐Viridiflorol, (−)‐Palustrol, (+)‐Spathulenol, and Psiguadial A, C, and D via the Platform Terpene (+)‐Bicyclogermacrene / Molecular Chalcoxides (ChalcoPolyoxometalates): A Family of Functional Materials with Emergent Properties / A SIM‐MOF: Three‐Dimensional Organisation of Single‐Ion Magnets with Anion‐Exchange Capabilities (Chem. Eur. J. 34/2014)09/28/2019

The Young Chemists Special Issue has been put together to celebrate the past winners of the European Young Chemist Award (EYCA), presented at the first four EuCheMS Congresses, and to highlight the great diversity of research currently being conducted by young chemists from all over the world. N...detailed

Laser‐SNMS investigations on Pyrene (cas 129-00-0) using Ga+, Bi1+, Bi3+ and Bi5+ as primary ions and different laser wavelengths and laser power densities for photoionization09/26/2019

Laser secondary neutral mass spectrometry (Laser‐SNMS) has been used to simultaneously ionize sputtered secondary neutrals in a nonselective way. To investigate the sputtering and photoionization processes, we examined the dependence of the Laser‐SNMS molecular yield on (i) different primary i...detailed

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Surfactant-Concentration Effects in Photoinduced Electron Transfer from Pyrene to Cupric Ions in Sodium Dodecyl Sulfate Micelle Solutions

The decay of pyrene fluorescence and the quantum yield of pyrene cations were measured by using the laser photolysis method in sodium dodecyl sulfate (SDS) micelle solutions containing both pyrene and cupric dodecyl sulfate at 40 deg C.The decay curve of the pyrene fluorescence deviates from the first-order rate law at SDS concentrations below 0.2 M, as alredy known, but becomes first order at higher SDS concentrations.The rate shows incontinuity between 0.2 and 0.5 M SDS.The cation quantum yield remarkably increases with the SDS concentration: For 10 mM of cupric ion, the quantum yields were 0.25 and 0.60 at SDS concentrations of 0.05 and 0.8 M, respectively.These results can be explained in terms of involvement of large rodlike micelles in which the portion of the net electron transfer in quenching is larger than in usual spherical micelles.

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Photoionization of 10-methylphenothiazine, N,N,Na?2Na?2-tetramethylbenzidine, and pyrene in Cr-AlMCM-41 molecular sieves

Photoionization of 10-methylphenothiazine (PC1), N,N,Na?2,Na?2-tetramethylbenzidine (TMB), and pyrene (Py) impregnated into mesoporous AlMCM-41 ion-exchanged with Cr(III), as an electron acceptor, to give Cr-AlMCM-41 was investigated. Cation radicals (PC1a?￠+, TMBa?￠+, Pya?￠+) are produced by 320 nm light at room temperature and characterized by electron spin resonance (ESR) and UV-vis diffuse reflectance spectroscopy. The chromium ion concentration was varied from Si/Cr = 52 to 121. Cr-AlMCM-41 with the intermediate concentration of Si/Cr = 80 exhibits the greatest electron acceptor ability and shows the highest photoionization efficiency photoionized. The photoionization efficiency also depends on the type of photoionizable molecule impregnated into mesoporous Cr-AlMCM-41 with PC1 being the most efficiently photoionized. The calcination temperature used before impregnation controls the oxidation state of chromium ions to Cr3+ or Cr5+/Cr6+, which also affects the photoionization efficiency. Cr-AlMCM-41 with Cr5+ gives about 4 times higher photoionization efficiency than with Cr3+. Cr-AlMCM-41 is shown to be a promising heterogeneous host for the efficient formation of photoinduced cation radicals to achieve long-lived charge separation in solid-state systems.

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Electroreduction of 3-bromopyrene in DMF. A new organic electrochemical oscillator

The reduction of 3-bromopyrene in DMF at a mercury electrode for scan rates lower than 0.1 V s-1 is accompanied by a slow adsorption of an intermediate, resulting in a catalytic behaviour. The current oscillations take place in a region of the negative faradaic impedance.

Phototransformations of environmental contaminants in models of the aerosol: 2 and 4-Nitropyrene

A comparative photochemical study of 2- and 4-nitropyrene (2- and 4-NO2Py) in different organic solvents was performed in order to provide information on the fate of these contaminants in models of the atmospheric aerosols. The isomers presented small photodegradation yields, 10?4–10?5 for 4-NO2Py and 10?5–10?6 for 2-NO2Py, demonstrating the low reactivity of the excited states and intermediate species that participate in their photodegradation. Photoproducts such as 4,5-pyrenedione, 4-hydroxypyrene, aminopyrene and pyrene were identified during the irradiation of 4-NO2Py. Substantial differences were observed in the photodegradation yields, and type and relative yields of the photoproducts of the 2-NO2Py and 4-NO2Py when compared to those of 1-NO2Py. These differences were related with the orientation of the nitro group and with differences in intersystem crossing rates which affect the yields of the pyrenoxy radical (PyO) and of the (π,π*) triplet state, principal precursors in their photodegradation. The smallest photodegradation yield was for 2-NO2Py due to the lack of interaction between the nitro group and the aromatic moiety thus resulting in a low yield of formation of the PyO radical. In the presence of O2, the photodegradation quantum yields of 4-NO2Py were reduced in all solvents due the quenching of the (π,π*) triplet state, and 4-aminopyrene was not observed thus demonstrating that its formation occurs from this state. These results suggest that in atmospheric aerosols containing an organic liquid-like layer, the nitropyrene isomers will show low photoreactivity resulting in an increase in their residence time in the atmosphere. An increase in reactivity is expected when the excited nitropyrenes are nearby substances with hydrogen donor capacities such as phenols. The photoproducts formed in the transformation could increase the toxicity of the particulate matter in the atmosphere.

Photophysical Properties of Pyrene in Zeolites: A Direct Time-Resolved Diffuse Reflectance Study of Pyrene Anion Radicals in Zeolites X and Y

The formation of pyrene anion radicals (Py.-) in the supercage of different alkali-ion-exchanged zeolites X and Y was studied using direct time-resolved diffuse reflectance techniques.Many factors such as the Si/Al ratio, the nature of charge balancing cations, the preactivation temperature, the pyrene loading, the state of hydration, and the nature of the surfaces (external versus internal) were examined in order to understand the formation and stabilization of Py.- in these samples, and also the mechanism of the photoinduced electron transfer processes.The results show that photoinduced electron transfer does not occur from pyrene to pyrene in the zeolites but occurs between pyrene molecule and the acidic and basic sites of the zeolites.The basic sites of the zeolites, responsible for the formation of Py.-, are framework oxygen.Stabilization of Py.- requires the special environment of the zeolite supercage; it is noteworthy that Py.- cannot be formed on the external surface of a zeolite.The formation of Py.- in the different alkali-ion-exchanged zeolites X- and Y follows the order of basicity of these samples, which is calculated using the Sanderson electronegativity equalization principle.Preactivation of the samples at temperatures of 350, 550, and 750 deg C does not affect the ratio of the anion to cation, Py.-/Py.+, yields.Posthydration of the samples alters the photophysical processes in the zeolites and gives rise to an increase in the yield of Py.-.At low light intensities, the photoinduced electron transfer follows a single-photon increase in the yield of Py.-.At low light intensities, the photoinduced electron transfer follows a single-photon mechanism.

A forgotten olefin: A convenient one-pot cascade reaction involving Suzuki-Miyaura and Mizoroki-Heck couplings to form (E)-1,2-Di(pyren-1-yl) ethylene

The addition of 0.5 equiv of vinylboronic acid pinacol ester I to 1-bromopyrene derivative 3 in the presence of [Pd(PPh3)4] and K 2CO3 induced a cascade reaction involving SuzukiMiyaura and MizorokiHeck couplings and afforded (E)-1,2-di(pyren-1-yl)ethylene derivative 1b. An alternative synthesis of 1b was carried out by an olefin metathesis. Formed 1b showed absorption bands in the visible region and a low oxidation potential attributable to a narrow HOMO-LUMO gap.

Towards modelling light processes of blue-light photoreceptors. Pyrene-isoalloxazine (flavin)-phenothiazine triad: Electrochemical, photophysical, investigations and quantum chemical calculations

The triad 6 containing the phenothiazine-isoalloxazine couple as donor-acceptor redox unit and pyrene as antenna absorbing in the UV-A region has been designed to mimic the light processes of natural photoreceptors. By cyclic voltammetry it is shown that the redox chemistry of the three subunits of triad 6 behave almost independently, indicating no electronic coupling between the subunits in the ground state. Triad 6 exhibits three accessible redox states with one oxidation and two reduction waves due to the formation of the phenothiazine radical cation and isoalloxazine and pyrene radical anions. UV/Vis/NIR spectroelectrochemistry reveals the generation of the protonated isoalloxazine dianion on reduction which is formed in the non-polar solvent in a reduction-protonation-reduction step (two-electron transfer process) and which is attributed to intermolecular proton transfer from the amide group to the electrochemically reduced isoalloxazine radical anion. Evidences for the photoinduced energy and electron transfer within the triad are provided by steady state and time-resolved absorption and fluorescence measurements. Spectroscopic studies displayed that upon excitation the pyrene emission was dramatically quenched in the dyad 4. This is most likely due to the energy transfer from pyrene to the isoalloxazine units as the absorption band of isoalloxazine overlaps with the pyrene emission band leading most likely to a CT state of the isoalloxazine/phenothiazine type. Quenching of the phenothiazine fluorescence in triad 6 was also ascribed to the spectroscopic overlap between the emission spectrum of phenothiazine and absorption spectrum of isoalloxazine. Again, photoinduced electron transfer from phenothiazine to isoalloxazine is expected to be the cause for the quenching of the isoalloxazine emission in the dyad 5. Molecular orbital calculations for compound 5 showed a complete electron transfer from phenothiazin to isoalloxazine.

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Metacyclophanes and Related Compounds. 19. Reaction of 8-Methoxymetacyclophanes with Iodine in Benzene Solution. A Preparative Route of Pyrene

When 8-methoxymetacyclophanes are treated with iodine in boiling benzene, the corresponding tetrahydropyrenes (8) are obtained in good yield.The AlCl3-catalyzed trans-tert-butylation of 8 effected loss of the tert-butyl group to give 10a-c, which were easily dehydrogenated with DDQ to afford the corresponding pyrene derivatives.

Origin of Pyrene under High Temperature Conditions in the Gas Phase. The Pivotal Role of Phenanthrene

4-Ethynylphenanthrene (15), and the latent precursors for 2-ethynyl- (18) and 3-ethynylphenanthrene (19), viz., 2-(1-chloroethenyl)- (16) and 3-(1-chloroethenyl)phenanthrene (17), respectively, have been subjected to flash vacuum thermolysis (FVT). Whereas at 800°C 15 is quantitatively converted into pyrene (1), 16 and 17 only give 18 and 19, respectively. Both 18 and 19 contain redundant ethynyl substituents, i.e., after ethynyl-ethylidene carbene equilibration neither five-nor six-membered ring formation can occur by carbene C-H insertion. At T ≥ 1000°C 16 and 17 gave pyrolysates containing the same set of 11 (non)-alternant polycyclic aromatic hydrocarbons (PAH), albeit in a different ratio. The different product ratio suggests that redundant ethynyl substituents migrate along the phenanthrene periphery presumably via transient cyclobuta-PAH intermediates toward positions suitable for either five- or six-membered ring formation by carbene C-H insertion. The results provide an explanation for the ubiquitous formation of pyrene (1), acephenanthrylene (9), and fluoranthene (3) during (incomplete) combustion. Phenanthrene (2) appears to be a point of divergence in PAH growth by C2 addition.

INVESTIGATION OF THE FORMATION OF HIGH MOLECULAR HYDROCARBONS AND SOOT IN PREMIXED HYDROCARBON-OXYGEN FLAMES.

Measurements of concentrations of high molecular hydrocarbons in laminar flat low pressure flames with various hydrocarbons under sooting conditions are reported. The results show that for all fuels investigated in that region of the flames where the bulk of soot is formed besides the main combustion products some characteristic groups of species are to be found. Within these groups of species only few fuel specific characteristics are stated. The main fuel specific influence lies in the relative concentration for the species. A reaction scheme for the qualitative explanation of the results found is discussed.

Pulse Radiolysis of trans-Stilbene in Tetrahydrofuran. Spektral Shift and Decay Kinetics of the Radical Anions in the Presence of Quaternary Ammonium Salts

Pulse radiolysis of trans-stilbene (St) in tetrahydrofuran (THF) solution was carried out in the presence of quaternary ammonium salts, such as Bu4NPF6, Bu4NI, Bu4NBPh4, CeMe3NPF6, PhMe3NPF6, and BzMe3NPF6 (Bu, butyl; Ce, cetyl; Me, methyl; Ph, phenyl; and Bz, benzyl).The absorption peak of the radical anions, St-., was shifted to shorter wavelengths in the presence of the salts.The magnitude of the shift depends on the substituent groups of the quaternary ammonium cations.It is suggested that St-. forms contact ion pairs with the quaternary ammonium cations.The decay rate of St-. decreases with increasing salt concentration and becomes steady.The rate constants for the neutralization reaction of St-. with the solvent counterions, THF(H+), have been determined in the absence and presence of Bu4NPF6; in the latter case, the reaction occurs between the ion pairs St-./Bu4N+ and THF(H+)/PF6-.The results for other aromatic compounds such as bibhenyl, anthracene, and pyrene are also presented.Comparison was made with the effect of NaBPh4.

Effects of an oxidation catalytic converter and a biodiesel fuel on the chemical, mutagenic, and particle size characteristics of emissions from a diesel engine

This study was conducted to obtain additional information on exhaust emissions with potential health importance from an indirect injection diesel engine, typical of those in use in underground mines, when operated using a soy-derived, fatty-acid mono-ester (or biodiesel) fuel and an oxidation catalytic converter (OCC). Compared to emissions with the diesel fuel without the OCC, use of the diesel (D2) and biodiesel fuel with the OCC had similar reductions (50-80%) in total particulate matter (TPM). The solid portion of the TPM was lowered with the biodiesel fuel. Particle-associated polynuclear aromatic hydrocarbon and 1-nitropyrene emissions were lower with use of the biodiesel fuel as compared to the D2 fuel, with or without the OCC. Vapor- phase PAH emissions were reduced (up to 90%) when the OCC was used with either fuel. Use of the OCC resulted in over 50% reductions in both particle and vapor-phase-associated mutagenic activity with both fuels. No vapor- phase-associated mutagenic activity was detected with the biodiesel fuel; only very low levels were detected with the D2 fuel and the OCC. Use of the OCC caused a moderate shift in the particle size/volume distribution of the accumulation mode particles to smaller particles for the diesel fuel and a reduction of particle volume concentrations at some of the tested conditions for both fuels. The nuclei mode did not contribute significantly to total particle volume concentrations within the measured particle size range (~0.01-1.0 μm). The biodiesel fuel reduced total particle volume concentrations. Overall, use of this OCC for the engine conditions tested with the biodiesel fuel, in particular, resulted in generally similar or greater reductions in emissions than for use of the D2 fuel. Use of the biodiesel fuel should not increase any of the potentially toxic, health- related emissions that were monitored as part of this study. Detailed information necessary to evaluate impact of using a biodiesel fuel on potentially health-related emissions from a diesel engine typical of those used in many underground mining operations are provided. Compared to emissions with the diesel fuel without the oxidation catalytic converter (OCC), use of the diesel (D2) and biodiesel fuel with the OCC had a similar reductions in total particulate matter (TPM). The solid portion of the TPM was lowered with the biodiesel fuel. Particle-associated polynuclear aromatic hydrocarbon and 1-nitropyrene emissions were lower with use of the biodiesel fuel as compared to the D2 fuel, with or without the OCC.

Azupyrene. Thermal Isomerization. Nitration by Silver Nitrite

Azupyrene (dicyclopentaheptalene) undergoes thermal isomerization to pyrene and nitration in the 3-position by silver nitrite.

Photoinduced Electron Transfer in Organized Assemblies

Photoexcitation of charge-transfer systems pyrene-dimethylaniline and pyrene-dibutylaniline has been studied in several organized assemblies, micelles, microemulsions, and vesicles.Both steady state measurements and pulse laser photolysis date show that the quenching of excited pyrene on the surface by the anilines is rapid but can be described by diffusional-type processes.Detailed mechanisms of the processes are discussed.The main products of the quenching are pyrene anions and dialkylaniline cations.Increasing the size of the assemblies, i.e., micelle to microemulsion or increasing the rigidity of the reactant's environment, i.e., micelle to vesicle, led to decreased yeilds of ions.The yeilds of ions in these latter systems can be restored if polar derivatives of pyrene are used in place of pyrene, thus locating the pyrene chromophore in the region of the assembly surface.Several reactions of the photoproduced pyrene anion were studied, as the lifetime of the anion is sufficiently long (>1 ms) to promote electron transfer between cationic ions such as Eu3+ and methyl viologen, in spite of the fact that these ions are strongly repelled by the cationic surfaces of the assemblies.It is concluded that efficient electron transfer and subsequent ion separation only occur when the rectants are located on strongly charged surfaces, where the reactants may move relatively freely, while still remaining bound to the surface.A photodiode effect is suggested to explain the efficient ion separation observed.

Unexpected high temperature behaviour of 2,2′-diethynylbiphenyl in the gas phase - A precursor for acephenanthrylene instead of pyrene

Flash Vacuum Thermolysis (FVT) of 2,2′-diethynylbiphenyl (6) gave, instead of pyrene (5), acephenanthrylene (10) and fluoranthene (11) as major products. The unequivocal identification of 9-ethynylphenanthrene (12) at T ≤ 800°C suggests that 12 is the initial stable product derived from 6. It is documented that under high-temperature conditions in the gas phase compound 12 is efficiently converted into 10, which subsequently rearranges to 11. The formation of 12 from 6 is rationalized by invoking the transient formation of cyclobuta[l]phenanthrene (13) by intramolecular cyclization of the ethynyl moieties of 6 followed by a reiro-carbene C-H insertion and a 1,2-H shift. This interpretation is supported by the results of independent FVT of 2,2′-bis(1-chloroethenyl)biphenyl (15). Wiley-VCH Verlag GmbH, 1997.

Regulation of one-electron oxidation rate of guanine and hole transfer rate in DNA through hydrogen bonding

The effects of methyl and bromo groups at C5 of C on the one-electron oxidation rate of G, and on the hole transfer rate in DNA have been investigated. The rates of one-electron oxidation of G and hole transfer from Py·+ to 8-oxo-7,8-dihydrogua

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Rediscovering Bacon's hydrazine/phenylhydrazine mediated cyclization of 2,2′-dicarbonylbi(hetero)aryls: Construction of (5-azo)-/indazolo[2,3-: A] quinolines

Hydrazine/phenylhydrazine-mediated reductive dicarbonyl coupling reactions have been carried out under mild conditions to provide polycyclic aromatic compounds and azo-substituted polyaromatic compounds. This method has a broad substrate scope with good functional group compatibility. This journal is

Pyrene-tiaraed pillar[5]arene: Strong intramolecular excimer emission applicable for photo-writing

A pyrene-tiaraed pillar[5]arene derivative was synthesized, which showed a concentration-independent intensive excimer emission. Photolysis of the pyrene-tiaraed pillar[5]arene led to a switch from excimer to monomer emission, applicable to photo-writing.