208-96-8

Basic information

• Product Name: Acenaphthalene
• Synonyms: Cyclopenta[de]naphthalene;NSC 59821;Acenaphthalene
• CAS NO: 208-96-8
• Molecular Formula: C₁₂H₈
• Molecular Weight: 152.20
• EINECS: 205-917-1
• Mol File: 208-96-8.mol
• Article Data: 69

Chemical Properties

• Melting Point: 78-82℃
• Boiling Point: 298.86 °C at 760 mmHg
• Flash Point: 137.161 °C
• Appearance: yellow crystalline powder
• Density: 1.187 g/cm³
• Vapor Pressure: 0.0022mmHg at 25°C
• Refractive Index: 1.731
• CAS DataBase Reference: Acenaphthalene(CAS DataBase Reference)
• NIST Chemistry Reference: Acenaphthalene(208-96-8)
• EPA Substance Registry System: Acenaphthalene(208-96-8)

Safety Data

• Hazard Codes: Xi:Irritant
• Statements: R36/37/38:
• Safety Statements: S26:; S37/39:
• Hazardous Substances Data: 208-96-8(Hazardous Substances Data)

Usage

General Description

Acenaphthalene is a polycyclic aromatic hydrocarbon (PAH) compound that is formed by the fusion of two naphthalene rings. It is a white, crystalline solid that is similar in structure to naphthalene but has an additional benzene ring. Acenaphthalene is used as a precursor for the synthesis of various organic compounds and is also found in coal tar and cigarette smoke. It has been identified as a potential environmental pollutant due to its carcinogenic and toxic properties, and it has been found to bioaccumulate in aquatic organisms. Acenaphthalene is also used in the production of dyes, pesticides, and pharmaceuticals, and it is a known mutagen and suspected human carcinogen. Overall, acenaphthalene is a compound of environmental and industrial concern due to its potential health and environmental effects.

InChI:InChI=1/C12H8/c1-3-9-4-2-6-11-8-7-10(5-1)12(9)11/h1-8H

Synthetic route

1-bromo-1H,3H-naphtho<1,8-cd>thiopyran 2,2-dioxide (51392-61-1) → acenaphthylene (208-96-8)

Conditions	Yield
With sodium methylate In methanol for 16.5h; Ambient temperature;	97%
With sodium methylate In methanol for 16.5h; Product distribution; Ambient temperature; var. of base;	97%

acenaphthene (83-32-9) + 7,7',8,8'-tetracyanoquinodimethane (1518-16-7) → 9-Acenaphthyl<4-(dicyanomethyl)phenyl>dicyanomethane (77074-97-6) + acenaphthylene (208-96-8)

Conditions	Yield
for 0.0833333h; Heating;	A 95.5% B n/a

Carbonic acid acenaphthen-1-yl ester methyl ester (164665-41-2) → acenaphthylene (208-96-8)

Conditions	Yield
With 1,2-bis-(diphenylphosphino)ethane; bis(dibenzylideneacetone)-palladium(0) In N,N-dimethyl-formamide at 60℃; for 48h;	95%

Propynoic acid acenaphthen-1-yl ester (182313-38-8) → acenaphthylene (208-96-8)

Conditions	Yield
at 760℃; under 0.03 Torr;	95%
Multi-step reaction with 2 steps 1: 32 percent / deuterium oxide, triethylamine / tetrahydrofuran / 1.25 h / 35 °C 2: 95 percent / 760 °C / 0.03 Torr View Scheme

1,2-dihydroacenaphthylen-1-yl (3-(2)H)propyonate → acenaphthylene (208-96-8)

Conditions	Yield
at 760℃; under 0.03 Torr;	95%

trans-1,2-dibromo-1,2-dihydroacenaphthylene (25226-58-8) → acenaphthylene (208-96-8)

Conditions	Yield
With acetic acid; zinc	94%
With ethanol; zinc

1,2-dibromoacenaphthene (14209-08-6) → acenaphthylene (208-96-8)

Conditions	Yield
With sodium sulfide; Aliquat 336 In water; benzene for 1h; Ambient temperature;	92%

1-acenaphthenol (6306-07-6) → acenaphthylene (208-96-8)

Conditions	Yield
methyltrioxorhenium(VII) In benzene for 72h;	89%
zirconium(IV) chloride In acetonitrile at 20℃; for 0.666667h;	89%
With pyridine; thionyl chloride

C27H20N2O2 → (E)-1,2-diphenyl-ethene (103-30-0) + acenaphthylene (208-96-8)

Conditions	Yield
at 500℃; under 0.02 Torr; for 0.0833333h;	A 88% B 4%

2-[2-(1-chloro-vinyl)-phenyl]-thiophene → naphtho[1,2-b]thiophene (234-41-3) + acenaphthylene (208-96-8)

Conditions	Yield
at 800℃; under 0.1 Torr; Cyclization; Pyrolysis;	A 81% B 2%

acenaphthene (83-32-9) → acenaphthylene (208-96-8)

Conditions	Yield
With 2,3-dicyano-5,6-dichloro-p-benzoquinone In toluene for 24h; Reflux;	80%
With oxygen; 2,3-dicyano-5,6-dichloro-p-benzoquinone; sodium nitrite In toluene at 120℃; under 9750.98 Torr; for 8h;	77%
With manganese(IV) oxide In benzene for 30h; Heating;	41%

1-acenaphthenol (6306-07-6) → acenaphthene-1-thiol + acenaphthylene (208-96-8)

Conditions	Yield
With Lawessons reagent In toluene for 0.5h; Heating;	A 72% B 13%
With Lawessons reagent In toluene for 0.5h; Heating;	A 72% B 13%

acenaphthene (83-32-9) + chloranil (118-75-2) → 2,3,5,6-tetrachlorobenzene-1,4-diol (87-87-6) + acenaphthylene (208-96-8)

Conditions	Yield
In benzene for 18h; Irradiation;	A 68% B 19%

(acenaphthylene)chromium tricarbonyl (99414-44-5) + ethyl α-lithioisobutyrate → C36H34O4 + C18H18O2 (106017-42-9) + acenaphthylene (208-96-8)

Conditions

Yield

With N,N,N,N,-tetramethylethylenediamine; iodine In tetrahydrofuran Kinetics; to a soln. of nucleophile in THF was added soln. of complex in THF at -60°C; after 45 min at -60°C I2 in THF was added and soln. allowed to stir overnight while being warmed to room temp.;; soln. was filtered through Celite, evapd., extd. with ether, extract was washed with other solvents, then chromd. on silica column, eluent CHCl3-hexane;;

A 19% B 20% C 68%

C27H37BSi2 → acenaphthylene (208-96-8)

Conditions	Yield
With 2,3-dicyano-5,6-dichloro-p-benzoquinone In toluene for 24h; Schlenk technique; Inert atmosphere; Reflux;	57%

(acenaphthylene)chromium tricarbonyl (99414-44-5) + ethyl α-lithioisobutyrate → C18H18O2 (106017-42-9) + acenaphthylene (208-96-8)

Conditions

Yield

With N,N,N,N,-tetramethylethylenediamine; iodine; trifluoroacetic acid In tetrahydrofuran to a soln. of nucleophile in THF at -60°C soln. of complex was added, after 45 min at -60°C CF3COOH was added followed by I2, and soln. was allowed to stir overnight while being warmed to room temp.;; soln. was filtered through Celite, evapd.; residue was extd. was ether and washed with other solvents; then chromd. on silica column, eluent CH2Cl2-hexane;;

A 47% B 8%

C27H20N2O2 → (E)-1,2-diphenyl-ethene (103-30-0) + acenaphthene (83-32-9) + acenaphthylene (208-96-8)

Conditions	Yield
at 780℃; under 1 Torr; for 0.0833333h;	A 43% B 19% C 37%

dichloromethane (75-09-2) + (naphthalene-1,8-diyl)dilithium (61767-59-7) → naphthalene (91-20-3) + 1,1'-cis-ethene-1,2-diyl-bis-naphthalene (1233-36-9, 3960-21-2, 72597-92-3, 72597-93-4, 85248-67-5, 2633-10-5) + (E)-1,2-bis(1-naphthyl)ethene (1233-36-9) + 1H-Cyclobutanaphthalene (24973-91-9) + 1-Chloromethylnaphthalene (86-52-2) + acenaphthylene (208-96-8)

Conditions	Yield
With N,N,N,N,-tetramethylethylenediamine In diethyl ether at -100 - -60℃; Product distribution; Mechanism; var. of temp., further with CD2Cl2;	A 42% B n/a C n/a D 21% E n/a F n/a

dichloromethane (75-09-2) + (naphthalene-1,8-diyl)dilithium (61767-59-7) → naphthalene (91-20-3) + 1,1'-cis-ethene-1,2-diyl-bis-naphthalene (1233-36-9, 3960-21-2, 72597-92-3, 72597-93-4, 85248-67-5, 2633-10-5) + 1H-Cyclobutanaphthalene (24973-91-9) + acenaphthylene (208-96-8)

Conditions	Yield
With N,N,N,N,-tetramethylethylenediamine In diethyl ether at -100 - -60℃; Further byproducts given;	A 42% B n/a C 21% D n/a

(acenaphthylene)chromium tricarbonyl (99414-44-5) + lithium N,N-diethylisobutyramide → C40H44N2O2 (106017-45-2) + C20H23NO (106017-44-1) + acenaphthylene (208-96-8)

Conditions

Yield

With N,N,N,N,-tetramethylethylenediamine; iodine In tetrahydrofuran to a soln. of nucleophile in THF at -60°C soln. of complex was added, after 45 min at -60°C soln. of I2 in THF was added, and soln. was allowed to stir overnight while being warmed to room temp.;; soln. was filtered through Celite, evapd.; residue was extd. was ether and washed with other solvents; then chromd. on silica column, eluent CH2Cl2-hexane;;

A 16% B 42% C 41%

2-(2-ethynyl-phenyl)-thiophene (221230-46-2) → naphtho[1,2-b]thiophene (234-41-3) + acenaphthylene (208-96-8)

Conditions	Yield
at 1000℃; under 0.1 Torr; Cyclization; rearrangement; Pyrolysis;	A 18% B 41%

acenaphthene quinone (82-86-0) → 1-acenaphthenol (6306-07-6) + acenaphthene (83-32-9) + acenaphthylene (208-96-8)

Conditions	Yield
With samarium diiodide; water In tetrahydrofuran at 20℃; for 0.00277778h;	A 41% B 26% C 23%

C20H15N2O4S(1-)*Li(1+) → acenaphthene (83-32-9) + 9-Hydroxymethyl-1H-naphtho[1,2-c]furan-3-one (182313-44-6) + acenaphthylene (208-96-8)

Conditions	Yield
at 730℃; under 0.03 Torr; for 0.05h;	A 9% B 38% C 12%

1,3-dibromo-1H,3H-naphtho<1,8-cd>thiopyran 2,2-dioxide (83831-93-0, 83831-94-1) → decacyclene (191-48-0) + 1-bromoacenaphthylene (54736-49-1) + acenaphthylene (208-96-8)

Conditions	Yield
With potassium tert-butylate In tert-butyl alcohol at 27℃; for 18h; Product distribution; other reagents;	A 5% B 33% C 23%
With potassium tert-butylate In tert-butyl alcohol for 1.5h; Heating;	A 5% B n/a C n/a

acenaphthene quinone (82-86-0) → decacyclene (191-48-0) + 1-acenaphthenol (6306-07-6) + acenaphthene (83-32-9) + acenaphthylene (208-96-8)

Conditions	Yield
bis(η6-biphenyl)titanium(0) In toluene at 110℃; for 2h; Further byproducts given;	A 21% B 10% C 11% D 31%

acenaphthene quinone (82-86-0) → decacyclene (191-48-0) + trans-biacenaphthylidene (24290-66-2) + cis-biacenaphthylidene (24290-65-1) + acenaphthylene (208-96-8)

Conditions	Yield
bis(η6-biphenyl)titanium(0) In toluene at 110℃; for 2h; Yield given. Further byproducts given;	A 21% B n/a C n/a D 31%

1,2-dihydroacenaphthylen-1-yl diazoacetate (182313-50-4) → acenaphthylene (208-96-8)

Conditions	Yield
at 340℃; under 0.02 Torr;	22%

C24H31BSi2 → acenaphthylene (208-96-8)

Conditions	Yield
With 2,3-dicyano-5,6-dichloro-p-benzoquinone In toluene for 24h; Schlenk technique; Inert atmosphere; Reflux;	21%

(acenaphthylene)chromium tricarbonyl (99414-44-5) + lithium isobutyronitrile (55440-70-5) → C16H13N (106017-41-8) + acenaphthylene (208-96-8)

Conditions

Yield

With N,N,N,N,-tetramethylethylenediamine; iodine; trifluoroacetic acid In tetrahydrofuran to a soln. of nucleophile in THF at -60°C soln. of complex was added, after 45 min at -60°C CF3COOH was added followed by I2, and soln. was allowed to stir overnight while being warmed to room temp.;; soln. was filtered through Celite, evapd.; residue was extd. was ether and washed with other solvents; then chromd. on silica column, eluent CH2Cl2-hexane;;

A 20% B 3%

acenaphthylene (208-96-8) → acenaphthene (83-32-9)

Conditions	Yield
With tetraethylammonium bromide In ethanol at 60℃; electrolysis, lead cathode;	100%
With benzenetellurol In ethanol; ethyl acetate for 4h; Product distribution; Heating; other reagent, reaction time;	98%
With iodine; hypophosphorous acid In acetic acid for 24h; Heating;	98%

acenaphthylene (208-96-8) + benzenesulfenyl chloride (931-59-9) → trans-2-phenylthio-1-chloroacenaphthene

Conditions	Yield
In acetic acid	100%

acenaphthylene (208-96-8) → acenaphthylene (14620-98-5)

Conditions	Yield
With 6-per-deoxy-6-per-(2-sulfoethyl)thio-γ-cyclodextrin, sodium salt for 12h; UV-irradiation; stereoselective reaction;	100%
With Rosebengal In methanol Irradiation;	65%
In hexane at 25℃; Irradiation;
With racemic palladium-ruthenium heterometallic cage with 3-{1H-imidazo[4,5-f]1,10-phenanthrolin-2-yl}pyridine In water; dimethyl sulfoxide at 20℃; Kinetics; Catalytic behavior; Reagent/catalyst; Solvent; Irradiation;

acenaphthylene (208-96-8) + tetrachlorothiophenium-NR → 7,8,9,10-Tetrachloro-6b,10a-dihydro-fluoranthene (72541-91-4)

Conditions	Yield
at 20℃; for 1h;	100%

acenaphthylene (208-96-8) → trans-1,2-dibromo-1,2-dihydroacenaphthylene (25226-58-8)

Conditions	Yield
With tri(decyl)(methyl)phosphonium tribromide In Hexadecane for 240h;	100%
With hydrogen bromide; oxygen; sodium nitrite In water; acetonitrile at 22℃; for 8h; diastereoselective reaction;	96%
With pyridinium hydrobromide perbromide In tetrahydrofuran at -78 - 20℃;	93%

methanol (67-56-1) + 4-allylguaiacol (97-53-0) + acenaphthylene (208-96-8) → 8-allyl-11,11-dimethoxy-6b,7,10,10a-tetrahydro-7,10-ethanofluoranthen-12-one

Conditions	Yield
Stage #1: methanol; 4-allylguaiacol With [bis(acetoxy)iodo]benzene; sodium hydrogencarbonate In benzene at 0℃; for 0.166667h; Stage #2: acenaphthylene In benzene at 20℃; for 22h; Diels-Alder reaction; stereoselective reaction;	100%

1,3-diphenyl-2H-cyclopenta<1>phenanthren-2-one (5660-91-3) + acenaphthylene (208-96-8) → C40H26 (1352187-64-4)

Conditions	Yield
In xylene Reflux;	100%

C18H14OS2 (1352187-65-5) + acenaphthylene (208-96-8) → C30H22OS2 (1352187-66-6)

Conditions	Yield
In diethyl ether; dichloromethane; o-xylene at 100 - 140℃; for 2h;	100%

acenaphthylene (208-96-8) → 6b,7a-dihydroacenaphtho [1,2-b]oxirene (22058-69-1)

Conditions	Yield
Stage #1: acenaphthylene With N-Bromosuccinimide In water; dimethyl sulfoxide at 20℃; for 2h; Stage #2: With sodium hydroxide In diethyl ether at 20℃;	99%
With 3,3-dimethyldioxirane In acetone at 20℃; for 1h;	97%
With 2-Nitrobenzenesulfonyl chloride In acetonitrile at -30℃; for 10h; Product distribution; various arenes, solvents + times;	95%

4-methylphenylboronic acid (5720-05-8) + acenaphthylene (208-96-8) → C19H16

Conditions	Yield
With 5,5’-bis(diphenylphosphino)-2,2,2’,2’-tetrafluoro-4,4’-bi-1,3-benzodioxole; [Rh(OH)(cod)]2 In 1,4-dioxane at 60℃; for 6h; Catalytic behavior; Reagent/catalyst; Inert atmosphere; Schlenk technique; enantioselective reaction;	99%

acenaphthylene (208-96-8) → 1(2H)-acenaphthylenone (2235-15-6)

Conditions	Yield
With oxygen; isobutyraldehyde In acetonitrile at 60℃; for 3h;	98%
With dinitrogen monoxide; dioxo(tetramesitylporphyrinato)ruthenium(VI) In fluorobenzene at 100℃; under 7500.6 Torr;	87%
With iodosylbenzene; iron(III) tetraphenylporphyrin In dichloromethane for 1h;	58%
With iodosylbenzene; μ-oxo dimer of iron(III)porphyrinate In methanol at 21.9℃; for 3h; Product distribution; Mechanism; catalysts also Fe(III)porphyrinate, Fe(III)tetraphenylporphyrinate; protic and aprotic solvents; inhibition effect by phenanthrene; by-products;	28%
With dinitrogen monoxide at 300℃; under 367754 Torr;

phenylselenium trichloride (42572-42-9) + acenaphthylene (208-96-8) → C18H13Cl3Se (109391-84-6)

Conditions	Yield
In diethyl ether at 0℃;	98%

N-ethoxycarbonyl-(2,3,4,5-tetrachloro-1-thiophenio)amide (90454-50-5) + acenaphthylene (208-96-8) → (6bS,10aR)-7,8,9,10-Tetrachloro-6b,10a-dihydro-fluoranthene (72541-91-4)

Conditions	Yield
at 20℃; for 0.166667h;	98%

4-trifluoromethylphenylboronic acid (128796-39-4) + acenaphthylene (208-96-8) → C19H13F3

Conditions	Yield
With 5,5’-bis(diphenylphosphino)-2,2,2’,2’-tetrafluoro-4,4’-bi-1,3-benzodioxole; [Rh(OH)(cod)]2 In 1,4-dioxane at 60℃; for 6h; Inert atmosphere; Schlenk technique; enantioselective reaction;	98%

p-methylbenzenesulfenyl chloride (933-00-6) + acenaphthylene (208-96-8) → trans-2-p-tolylthio-1-chloroacenaphthene

Conditions	Yield
In acetic acid	97%

tris(3-chlorophenyl)boroxine (7519-92-8) + acenaphthylene (208-96-8) → C18H13Cl

Conditions	Yield
With 5,5’-bis(diphenylphosphino)-2,2,2’,2’-tetrafluoro-4,4’-bi-1,3-benzodioxole; tert-Amyl alcohol; [Rh(OH)(cod)]2 In 1,4-dioxane at 60℃; for 6h; Inert atmosphere; Schlenk technique; enantioselective reaction;	97%

N-(ethoxycarbonyl)-(2,3,4,5-tetrachloro-1-thiophenio)amide S-oxide (106550-69-0) + acenaphthylene (208-96-8) → sulfinylcarbamic acid ethyl ester (5659-92-7) + (6bS,10aR)-7,8,9,10-Tetrachloro-6b,10a-dihydro-fluoranthene (72541-91-4)

Conditions	Yield
In dichloromethane for 1h;	A 89% B 96%

acenaphthylene (208-96-8) + 4-chloro-benzenesulfenyl chloride (933-01-7) → trans-2-(4-chlorophenyl)thio-1-chloroacenaphthene

Conditions	Yield
In acetic acid	96%

acenaphthylene (208-96-8) + N-(2-hydroxy-5-isopropylphenylsulfanyl)phthalimide → 6-(1-methylethyl)-2,3-dihydroacenaphthene[1,4]benzoxathiin

Conditions	Yield
With pyridine In chloroform at 70℃; for 24h;	96%

diphenyl acetylene (501-65-5) + acenaphthylene (208-96-8) → 7,8-diphenyl-6b,8a-dihydrobuta[a]acenaphtylene

Conditions	Yield
With Br2Co*C27H26P2; zinc(II) iodide; zinc In dichloromethane at 25℃; for 48h;	95%

bis(pinacol)diborane (73183-34-3) + acenaphthylene (208-96-8) → 2-(1,2-dihydroacenaphthylen-1-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (1449296-11-0)

Conditions	Yield
With methanol; (2-mesityl-5-methyl-2,3-dihydroimidazo[1,5-a]pyridin-3-yl)copper(I) chloride; sodium t-butanolate In diethyl ether at 20℃; for 0.5h; Inert atmosphere; Schlenk technique;	95%

1,3-diphenylisobenzofuran (5471-63-6) + acenaphthylene (208-96-8) → 10.13-Diphenyl-10.13-endoxy-11:12-benzo-9.10.13.14-tetrahydrofluoranthen (13093-44-2, 36213-63-5, 36213-64-6)

Conditions	Yield
In 5,5-dimethyl-1,3-cyclohexadiene Reflux;	94.85%
In benzonitrile at 140℃; for 7h;	60%

acenaphthylene (208-96-8) → 1,2,2a,3,4,5-hexahydro-acenaphthylene (480-72-8)

Conditions	Yield
With Raney Ni-Al In potassium hydroxide; water at 90℃; for 6.5h; Reduction;	94%
With hydrogen; nickel at 250℃;

acenaphthylene (208-96-8) → acenaphthene quinone (82-86-0)

Conditions	Yield
With benzeneseleninic anhydride In chlorobenzene at 120℃; for 2h;	94%
With N-Bromosuccinimide; water; 1-hydroxy-3H-benz[d][1,2]iodoxole-1,3-dione In dimethyl sulfoxide at 60 - 70℃; for 3h;	79%
With sodium dichromate; cerous nitrate In acetic acid for 19h; Ambient temperature;	36%

Upstream product

• 151-50-8 potassium cyanide 
• 31202-24-1 sodium 5-acenaphthenesulfonate 
• 954-06-3 biphenyl-2,3-dicarboxylic acid anhydride 
• 83-32-9 acenaphthene 
• 7446-08-4 selenium(IV) oxide 
• 64-19-7 acetic acid 
• 82-86-0 acenaphthene quinone 
• 74-98-6 propane 
• 2052-07-5 2-Bromobiphenyl 
• 34557-54-5 methane 
• 142-82-5 n-heptane 

Downstream Products

• 19380-20-2 8-phenyl-9ξ-propyl-(6br,9ac)-6b,8,9,9a-tetrahydro-acenaphtho[1,2-d]isoxazole 
• 206-44-0 fluoranthene 
• 2819-03-6 1-adamantyl radical 
• 208-96-8 acenaphthylene 
• 83-32-9 acenaphthene 
• 2235-15-6 1(2H)-acenaphthylenone 
• 94257-40-6 1-benzyl-1,2-dihydroacenaphthylene 
• 16331-65-0 t-butoxide 
• 90624-31-0 2-Phenyl-propan-2-ol anion 
• 74-86-2 acetylene 
• 6306-07-6 (R)-1,2-dihydroacenaphthylen-1-ol 
• 121961-98-6 (S)-(+)-1,2-dihydroacenaphthylen-1-ol 
• 352532-72-0 7,14-Bis[4-dodecylphenyl]acenaphtho[1,2-k]-fluoranthene 
• 352532-70-8 7,8,9,10-Tetrakis(4-dodecylphenyl)fluoranthene 

Relevant articles and documents

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2,3-Dihydro-1H-naphtho[1,8-cd]borinine as a Potent Precursor for Open-Shell Singlet B-Heterocycles

The reaction of naphthalene-1,8-diylbis[(trimethylsilyl)methanide] and dimethyl arylboronates afforded the corresponding 2,3-dihydro-1H-naphtho[1,8-cd]borinine as single diastereomers. Single-electron oxidation of the boron-containing heterocycles provided acenaphthylene through the generation boron-containing cyclic singlet biradicals.

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Effect of potassium hydroxide on PAH formation during toluene incineration

A laboratory-scale liquid-injection incinerator was used to incinerate toluene at 750°C and PAH emission was analyzed. The results indicate that the emission of solid-phase PAHs considerably increased when potassium hydroxide was added into a fuel-lean toluene flame; more potassium hydroxide resulted in more solid-phase PAHs. But this phenomenon was not observed for the fuel-rich toluene flame. The enhanced PAH formation is proposed as by-product of the partial oxidation or incomplete burning of soot in the secondary flame zone of the fuel-lean flame. It is suggested that reducing soot formation via potassium hydroxide addition may increase PAHs.

Direct Evidence on the Mechanism of Methane Conversion under Non-oxidative Conditions over Iron-modified Silica: The Role of Propargyl Radicals Unveiled

Radical-mediated gas-phase reactions play an important role in the conversion of methane under non-oxidative conditions into olefins and aromatics over iron-modified silica catalysts. Herein, we use operando photoelectron photoion coincidence spectroscopy to disentangle the elusive C2+ radical intermediates participating in the complex gas-phase reaction network. Our experiments pinpoint different C2-C5 radical species that allow for a stepwise growth of the hydrocarbon chains. Propargyl radicals (H2C?C≡C?H) are identified as essential precursors for the formation of aromatics, which then contribute to the formation of heavier hydrocarbon products via hydrogen abstraction–acetylene addition routes (HACA mechanism). These results provide comprehensive mechanistic insights that are relevant for the development of methane valorization processes.

RECORDING MATERIAL AND OPTICAL INFORMATION RECORDING MEDIUM

A recording material includes a dye-bonded polymer compound which contains a polymer compound to which a one-photon absorption dye is bonded, and a glass transition temperature of the recording material is higher than 200° C. An optical information recording medium includes a recording layer and an intermediate layer adjacent to the recording layer, and the recording layer contains the above-described recording material.