120-12-7

Basic information

• Product Name: Anthracene
• Synonyms: Anthracen;Coal tar pitch volatiles:anthracene;coaltarpitchvolatiles:anthracene;Crudeanthracene;p-Naphthalene;Sterilite hop defoliant;Tetra Olive N2G;tetraoliven2g
• CAS NO: 120-12-7
• Molecular Formula: C14H10
• Molecular Weight: 178.23
• EINECS: 204-371-1
• Product Categories: Pharmaceutical Intermediates;Aromatic Compounds;Aromatics Compounds;Anthracenes;Highly Purified Reagents;Other Categories;Zone Refined Products;Aromatics;AM to AQAnalytical Standards;AromaticsChemical Class;Chemical Class;Hydrocarbons;NeatsAnalytical Standards;PAHs;ArenesEssential Chemicals;Reagent Plus;Routine Reagents;Arenes;Building Blocks;Organic Building Blocks;A;A-BAlphabetic;Alpha Sort;AM to AQ;Volatiles/ Semivolatiles;ArenesOrganic Electronics and Photonics;Light Emitters and Dopants;OLED and PLED Materials;DetectionSpectroscopy;Biochemicals and Reagents;Fluorescence/Luminescence;Fluorescent Probes, Labels, Particles and Stains;Luminescent Compounds/Detection;Scintillation reagents;Scintillation ReagentsBiochemicals and Reagents;Acceptor Materials;Building Blocks;Chemical Synthesis;Donor Materials;Donor-Acceptor Materials;Light Emitters and Dopants;Materials Science;OLED and PLED Materials;Organic and Printed Electronics;Organic Building Blocks;Organic Photovoltaic
• Mol File: 120-12-7.mol
• Article Data: 567

Chemical Properties

• Melting Point: 215 °C
• Boiling Point: 340 °C(lit.)
• Flash Point: 121 °C
• Appearance: off-white to yellow/powder
• Density: 1.28
• Vapor Density: 6.15 (vs air)
• Vapor Pressure: 1 mm Hg ( 145 °C)
• Refractive Index: 1.5948
• Storage Temp.: APPROX 4°C
• Solubility: toluene: soluble20mg/mL, clear, colorless to faintly yellow
• PKA: >15 (Christensen et al., 1975)
• Explosive Limit: 0.6%(V)
• Water Solubility: 0.045 mg/L (25 ºC)
• Merck: 14,682
• BRN: 1905429
• CAS DataBase Reference: Anthracene(CAS DataBase Reference)
• NIST Chemistry Reference: Anthracene(120-12-7)
• EPA Substance Registry System: Anthracene(120-12-7)

Safety Data

• Hazard Codes: Xi,N,F,T,Xn
• Statements: 36/37/38-50/53-67-36-11-39/23/24/25-23/24/25-65-38-66-51/53
• Safety Statements: 26-60-61-24/25-16-9-45-36/37-62-36
• RIDADR: UN 3077 9/PG 3
• WGK Germany: 2
• RTECS: CA9350000
• TSCA: Yes
• HazardClass: 9
• PackingGroup: III
• Hazardous Substances Data: 120-12-7(Hazardous Substances Data)

Usage

Description

Anthracene is one of a group of chemicals called polycyclic aromatic hydrocarbons (PAHs). PAHs are often found together in groups of two ormore. They can exist inmore than 100 different combinations, but the most common are treated as a group of 15. PAHs are found naturally in the environment but they can also be made synthetically. Anthracene can vary in appearance from a colorless to pale yellow crystal-like solid. PAHs are created when products like coal, oil, gas, and garbage are burned but the burning process is not complete. Very little information is available on the individual chemicals within the PAH group; the majority of the information is for the entire PAH group. Anthracene is a solid white to yellow crystal, has a weak aromatic odor, and sinks in water. Its characteristics are boiling point, 3421°C; melting point, 2181°C; molecular weight, 178.22; density/specific gravity, 1.25 at 27 and 41°C; octanol–water coefficient, 4.45. It is soluble in absolute alcohol and organic solvents. Maximum absorption occurs at 218 nm.

Chemical Properties

Different sources of media describe the Chemical Properties of 120-12-7 differently. You can refer to the following data:
1. ANTHRACENE is a colorless solid; melting point 218 °C, blue fluorescence when pure; insoluble in water, slightly soluble in alcohol or ether, soluble in hot benzene, slightly soluble in cold benzene; transformed by sunlight into para -anthracene (C14H10)2.
2. Anthracene is colorless, to pale yellow crystalline solid with a bluish fluorescence. PAHs are compounds containing multiple benzene rings and are also called polynuclear aromatic hydrocarbons.

Physical properties

White to yellow crystalline flakes or crystals with a bluish or violet fluorescence and a weak aromatic odor. Impurities (naphthacene, tetracene) impart a yellowish color with green fluorescence.

Uses

Different sources of media describe the Uses of 120-12-7 differently. You can refer to the following data:
1. Anthracene has been shown to be soluble in a variety of binary and ternary mixtures of cyclohexanone, ethyl acetate, and methanol 1,2.
2. Anthracene is an aromatic hydrocarbonwith three fused rings, and is obtained by the distillationof crude oils. The main useis in the manufacture of dyes.It is an important source of dyestuffs.
3. Most of the PAHs are used to conduct research. Like most PAHs, anthracene is used to make dyes, plastics, and pesticides. It has been used to make smoke screens and scintillation counter crystals. (A scintillation counter is used to detect or count the number of sparks or flashes that occur over a period of time.)

Production Methods

Anthracene is obtained from coal tar in the fraction distilling between 300° and 400 °C. This fraction contains 5–10% anthracene, from which, by fractional crystallization followed by crystallization from solvents, such as oleic acid, and washing with such solvents as pyridine, relatively pure anthracene is obtained. It may be detected by the formation of a blue-violet coloration on fusion with mellitic acid. Anthracene derivatives, especially anthraquinone, are important in dye chemistry.

Definition

(C14H10) A white crystalline solid used extensively in the manufacture of dyes. Anthracene is found in the heavy- and green-oil fractions of crude oil and is obtained by fractional crystallization. Its structure is benzene-like, having three six-membered rings fused toanion gether. The reactions are characteristic of AROMATIC COMPOUNDS.

Reactions

Anthracene reacts: (1) With oxidizing agents, e.g., sodium dichromate plus sulfuric acid, to form anthraquinone, C6H4(CO)2C6H. (2) With chlorine in water or in dilute acetic acid below 250 °C to form anthraquinol and anthraquinone, at higher temperatures 9,10-dichloroanthracene. The reaction varies with the temperature and with the solvent used. The reaction has been studied using, as solvent, benzene, chloroform, alcohol, carbon disulfide, ether, glacial acetic acid, and also without solvent by heating. Bromine reacts similarly to chlorine. (3) With concentrated sulfuric acid to form various anthracene sulfonic acids. (4) With nitric acid, to form nitroanthracenes and anthraquinone. (5) With picric acid (1)HO·C6H2(NO2)3(2,4,6) to form red crystalline anthracene picrate, melting point 138 °C.

Synthesis Reference(s)

Journal of the American Chemical Society, 82, p. 3653, 1960 DOI: 10.1021/ja01499a046Synthetic Communications, 7, p. 161, 1977 DOI: 10.1080/00397917708050729Tetrahedron Letters, 35, p. 1131, 1994 DOI: 10.1016/0040-4039(94)88004-2

General Description

White to yellow solid with a weak aromatic odor. Sinks in water.

Air & Water Reactions

Flammable. Insoluble in water.

Reactivity Profile

Anthracene will spontaneously burst into flame on contact with chromic acid, and other strong oxidants.

Hazard

A questionable carcinogen.

Health Hazard

Different sources of media describe the Health Hazard of 120-12-7 differently. You can refer to the following data:
1. Carcinogenicity of anthracene is not known.Its toxicity is very low. An intraperitonealLD50 in mice is recorded at 430 mg/kg(NIOSH 1986).
2. Inhalation of dust irritates nose and throat. Contact with eyes causes irritation.

Fire Hazard

Anthracene is combustible.

Flammability and Explosibility

Nonflammable

Safety Profile

Moderately toxic by intraperitoneal route. A skin irritant and allergen. Questionable carcinogen with experimental neoplas tigenic and tumorigenic data. Mutation data reported. Combustible when exposed to heat, flame, or oxidizing materials. Moderately explosive when exposed to flame, Ca(OCl)z, chromic acid. To fight fire, use water, foam, CO2, water spray or mist, dry chemical. Explodes on contact with fluorine.

Potential Exposure

It is used as an intermediate in dye stuffs (alizarin), insecticides, and wood preservatives; making synthetic fibers, anthraquinone, and other chemicals. May be present in coke oven emissions, diesel fuel, and coal tar pitch volitiles.

Carcinogenicity

Anthracene was negative in mouse-skin-painting studies, and it is classified as a noncarcinogen by the IARC based on inadequate evidence. The methyl, anthryl, dimethyl, diprophyl, dinaphthyl, and tetramethyl derivatives of anthracene were noncarcinogenic except for 9,10-dimethyl anthracene, which may have contained impurities when tested.

Source

Concentrations in 8 diesel fuels ranged from 0.026 to 40 mg/L with a mean value of 6.275 mg/L (Westerholm and Li, 1994). Lee et al. (1992) reported concentration ranges of 100– 300 mg/L and 0.04–2 μg/L in diesel fuel and corresponding aqueous phase (distilled water), respectively. Schauer et al. (1999) reported anthracene in diesel fuel at a concentration of 5 μg/g and in a diesel-powered medium-duty truck exhaust at an emission rate of 12.5 μg/km. Anthracene was detected in a distilled water-soluble fraction of used motor oil at concentrations ranging from 1.1 to 1.3 μg/L (Chen et al., 1994). California Phase II reformulated gasoline contained anthracene at a concentration of 4.35 μg/kg. Gas-phase tailpipe emission rates from gasoline-powered automobiles with and without catalytic converters were 3.69 and 148 μg/km, respectively (Schauer et al., 2002). Thomas and Delfino (1991) equilibrated contaminant-free groundwater collected from Gainesville, FL with individual fractions of three individual petroleum products at 24–25 °C for 24 h. The aqueous phase was analyzed for organic compounds via U.S. EPA approved test method 625. Average anthracene concentrations reported in water-soluble fractions of kerosene and diesel fuel were 12 and 25 μg/L, respectively. Anthracene was ND in the water-soluble fraction of unleaded gasoline. The concentration of anthracene in coal tar and the maximum concentration reported in groundwater at a mid-Atlantic coal tar site were 5,000 and 0.02 mg/L, respectively (Mackay and Gschwend, 2001). Based on laboratory analysis of 7 coal tar samples, anthracene concentrations ranged from 400 to 8,600 ppm (EPRI, 1990). A high-temperature coal tar contained anthracene at an average concentration of 0.75 wt % (McNeil, 1983). Lehmann et al. (1984) reported an anthracene concentration of 34.8 mg/g in a commercial anthracene oil. Nine commercially available creosote samples contained anthracene at concentrations ranging from 5,500 to 14,000 mg/kg (Kohler et al., 2000). Anthracene was detected in asphalt fumes at an average concentration of 45.89 ng/m3 (Wang et al., 2001). 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 anthracene were 3.44 and 0.228 mg/kg of pine burned, 2.13 and 0.0230 mg/kg of oak burned, and 1.76 and 0.0061 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 anthracene emitted ranged from 558.7 ng/kg at 900 °C to 2,449.7 ng/kg at 800 °C. The greatest amount of PAHs emitted were observed at 750 °C (Mastral et al., 1999).

Environmental fate

Biological. Catechol is the central metabolite in the bacterial degradation of anthracene. Intermediate by-products included 3-hydroxy-2-naphthoic acid and salicylic acid (Chapman, 1972). Anthracene was statically incubated in the dark at 25 °C with yeast extract and settled domestic wastewater inoculum. Significant biodegradation with gradual adaptation was observed. At concentrations of 5 and 10 mg/L, biodegradation yields at the end of 4 wk of incubation were 92 and 51%, respectively (Tabak et al., 1981). A mixed bacterial community isolated from seawater foam degraded anthraquinone, a photodegradation product of anthracene, to traces of benzoic and phthalic acids (Rontani et al., 1975). In activated sludge, only 0.3% mineralized to carbon dioxide after 5 d (Freitag et al., 1985). Soil. In a 14-d experiment, [14C]anthracene applied to soil-water suspensions under aerobic and anaerobic conditions gave 14CO2 yields of 1.3 and 1.8%, respectively (Scheunert et al., 1987). The reported half-lives for anthracene in a Kidman sandy loam and McLaurin sandy loam are 134 and 50 d, respectively (Park et al., 1990). Surface Water. The removal half-lives for anthracene in a water column at 25 °C in midsummer sunlight were 10.5 h for deep, slow, slightly turbid water; 21.6 h for deep, slow, muddy water; 8.5 h deep, slow, clear water; 3.5 h for shallow, fast, clear water, and 1.4 h for very shallow, fast, clear water (Southworth, 1977). Photolytic. Oxidation of anthracene adsorbed on silica gel or alumina by oxygen in the presence of UV-light yielded anthraquinone. This compound additionally oxidized to 1,4-dihydroxy- 9,10-anthraquinone. Anthraquinone also formed by the oxidation of anthracene in diluted nitric acid or nitrogen oxides (quoted, Nikolaou et al., 1984) and in the dark when adsorbed on fly ash (Korfmacher et al., 1980). Irradiation of anthracene (2.6 mM) in cyclohexanone solutions gave 9,10-anthraquinone as the principal product (Korfmacher et al., 1980). Photocatalysis of anthracene and sulfur dioxide at -25 °C in various solvents yielded anthracene-9-sulfonic acid (Nielsen et al., 1983). Schwarz and Wasik (1976) reported a fluorescence quantum yield of 0.25 for anthracene in water. Chemical/Physical. In urban air from St. Louis, MO, anthracene reacted with NOx forming 9- nitroanthracene (Ramdahl et al., 1982).

Shipping

UN2811 Toxic solids, organic, n.o.s., Hazard Class: 6.1; Labels: 6.1-Poisonous materials, Technical Name Required.

Purification Methods

Likely impurities are anthraquinone, anthrone, carbazole, fluorene, 9,10-dihydroanthracene, tetracene and bianthryl. Carbazole is removed by continuous-adsorption chromatography [see Sangster & Irvine J Phys Chem 24 670 1956] using a neutral alumina column and eluting with n-hexane. [Sherwood in Purification of Inorganic and Organic Materials, Zief (ed), Marcel Dekker, New York, 1969.] The solvent is evaporated, and anthracene is sublimed under vacuum, then purified by zone refining, under N2 in darkness or non-actinic light. It has also been purified by co-distillation with ethylene glycol (boils at 197.5o), from which it can be recovered by addition of water, followed by crystallisation from 95% EtOH, *benzene, toluene, a mixture of *benzene/xylene (4:1), or Et2O. It has also been chromatographed on alumina with pet ether in a dark room (to avoid photo-oxidation of adsorbed anthracene to anthraquinone). Other purification methods include sublimation in a N2 atmosphere (in some cases after refluxing with sodium), and recrystallisation from toluene [Gorman et al. J Am Chem Soc 107 4404 1985]. Anthracene has been crystallised from EtOH, chromatographed through alumina in hot *benzene (fume hood) and then sublimed in a vacuum in a pyrex tube that has been cleaned and baked at 100o. (For further details see Craig & Rajikan J Chem Soc, Faraday Trans 1 74 292 1978, and Williams & Zboinski J Chem Soc, Faraday Trans 1 74 611 1978.) It has been chromatographed on alumina, recrystallised from n-hexane and sublimed under reduced pressure. [Saltiel J Am Chem Soc 108 2674 1986, Masnori et al. J Am Chem Soc 108 1126 1986.] Alternatively, recrystallise it from cyclohexane, chromatograph it on alumina with n-hexane as eluent, and recrystallise two more times [Saltiel et al. J Am Chem Soc 109 1209 1987]. Anthracene is fluorescent and forms a picrate complex, m 139o, on mixing the components in CHCl3 or *C6H6, but decomposes on attempted crystallization. [Beilstein 5 IV 228.]

Incompatibilities

Finely dispersed powder may form explosive mixture in air. Contact with strong 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, chromic acid/or calcium hypochlorite.

Waste Disposal

Consult with environmental regulatory agencies for guidance on acceptable disposal practices. Generators of waste containing this contaminant (≥100 kg/mo) must conform with EPA regulations governing storage, transportation, treatment, and waste disposal. Incineration.

InChI:InChI=1/C14H10/c1-2-6-12-10-14-8-4-3-7-13(14)9-11(12)5-1/h1-10H

Synthetic route

1,2,3,4-tetrahydroxy-1β,2α,3α,4β,4aβ,9α,9aβ,10α-hexahydro-9,10<1',2'>benzenoanthracene (125459-20-3) → anthracene (120-12-7) + conduritol A (526-87-4, 351885-26-2)

Conditions	Yield
at 460℃; under 0.1 Torr; for 0.5h;	A 100% B 100%

2,3-dihydroxy-1,4-dimethoxy-1β,2α, 3α,4β,4aβ,9α,9aβ,10α-octahydro-9,10<1',2'>benzenoanthracene (125459-21-4, 127761-11-9) → anthracene (120-12-7) + <1α,2α,3β,6β>-3,6-dimethoxycyclohex-4-ene-1,2-diol (125459-24-7)

Conditions	Yield
at 440℃; under 0.05 Torr; for 2h;	A 100% B 99%

C15H12S (59102-56-6) → thioformaldehyde (865-36-1) + anthracene (120-12-7) + CS2, H2S

Conditions	Yield
at 651.9℃; under 1E-06 Torr; sublimation through a short path flash vacuum pyrolysis (fvp) oven;	A n/a B 100% C n/a

C15H12OS (59102-57-7) → sulfinylmethane (40100-16-1) + anthracene (120-12-7) + SO2

Conditions	Yield
at 651.9℃; under 1E-06 Torr; sublimation through a short path flash vacuum pyrolysis (fvp) oven;	A n/a B 100% C n/a

C20H18O2 → 3,7-dioxabicyclo[3.3.0]oct-1,5-ene (53720-71-1) + anthracene (120-12-7)

Conditions	Yield
at 600℃; under 0.06 Torr;	A n/a B 100%

2-benzylbenzaldehyde (32832-95-4) → anthracene (120-12-7)

Conditions	Yield
With boron trifluoride diethyl etherate; toluene-4-sulfonamide In toluene at 20℃; for 0.166667h;	100%
With boron trifluoride diethyl etherate; toluene-4-sulfonamide In toluene at 20℃; for 0.166667h;	99%
With indium(III) triflate In 1,2-dichloro-ethane at 115℃; for 6h; Inert atmosphere;	94%

C14H10Yb (129823-92-3) → anthracene (120-12-7)

Conditions	Yield
With oxygen In 1,2-dimethoxyethane addn. of dry oxygen to a suspension of Yb complex;	100%

C14H10Sm → anthracene (120-12-7)

Conditions	Yield
With oxygen In 1,2-dimethoxyethane addn. of dry oxygen to a suspension of Sm complex;	100%

9,10-dihydroanthracene (613-31-0) → anthracene (120-12-7)

Conditions	Yield
With sulfuric acid; dinitrogen monoxide; Ru(5,10,15,20-tetramesitylporphyrin)(O)2 In benzene at 120℃; under 7600 Torr; for 4h;	99%
With oxygen; 2,3-dicyano-5,6-dichloro-p-benzoquinone; sodium nitrite In toluene at 120℃; under 9750.98 Torr; for 8h;	99%
With C64H50F8N6Ru In dichloromethane-d2 at 20℃; Reagent/catalyst; Schlenk technique; Inert atmosphere;	99%

9-chloroanthracene (716-53-0) → anthracene (120-12-7)

Conditions	Yield
With SmI2(hmpa)4 In tetrahydrofuran at 20℃; for 0.0166667h;	99%
With potassium tert-butylate; N,N-dimethyl-formamide at 35℃; for 24h; Schlenk technique; Inert atmosphere; Irradiation;	70%
With triethylamine In acetonitrile Product distribution; Quantum yield; Mechanism; Ambient temperature; Irradiation; quenching rate constants by azulene, ferrocene, and amines, decay rate constants of the radical anion;
With tetraethylammonium perchlorate In acetonitrile at 24.99℃; Electrochemical reaction;

9-Bromoanthracene (1564-64-3) → anthracene (120-12-7)

Conditions	Yield
With 2-H-1,3-di-tert-butyl-1,3,2-diazaphosphorinane; 2,2'-azobis(isobutyronitrile) In toluene at 90℃; for 5h;	99%
With 1,3-bis(2,6-diisopropylphenyl)-2,4-diphenylimidazole In N,N-dimethyl-formamide at 20℃; for 36h; Glovebox;	98%
With N1,N1,N12,N12-tetramethyl-7,8-dihydro-6H-dipyrido[1,2-a:2,1'-c][1,4]diazepine-2,12-diamine In N,N-dimethyl-formamide at 20℃; Inert atmosphere;	96%

<2α,3aβ,4β,4aβ,5β,10β,10aβ,11β,11aβ>-4,11-dimethoxy-2-phenyl-3a,4,4a,5,10,10a,11,11a-octahydro-5,10<1',2'>benzenoanthra<2,3-d>-1,3-dioxole → anthracene (120-12-7) + <2α,3aα,4α,7α,7aα>-2-phenyl-3a,4,7,7a-tetrahydro-1,3-benzodioxole

Conditions	Yield
at 440℃;	A 99% B 95%

anthracene-9-boronic acid (100622-34-2) → anthracene (120-12-7)

Conditions	Yield
With [bis(trifluoromethanesulfonyl)imidate](triphenylphosphine)gold(I); water In toluene at 90℃; for 2h; Microwave irradiation; Green chemistry;	99%
With acetic acid at 130℃; for 3h; Green chemistry;	92%
With sodium hypochlorite; tetrabutylammomium bromide; water at 100℃;	91%
With copper(l) chloride In methanol at 25℃; for 3h;

1,2,3,4-tetramethoxy-1β,2α, 3α,4β,4aβ,9α,9aβ,10α-octahydro-9,10<1',2'>benzenoanthracene (125459-22-5) → anthracene (120-12-7) + 3α,4β,5β,6α-tetramethoxycyclohex-4-ene-1α,2α-diol (86632-82-8)

Conditions	Yield
at 410℃; under 0.03 Torr; for 1.5h;	A 57 mg B 98%

9-anthracene aldehyde (642-31-9) → anthracene (120-12-7)

Conditions	Yield
With palladium diacetate; potassium carbonate In ethyl acetate at 150℃; under 12929 Torr; for 0.833333h; Microwave irradiation; Molecular sieve;	98%
With palladium nanoparticles supported on fibrous silica In cyclohexane at 130℃; for 20h; Molecular sieve;	98%
With palladium diacetate In cyclohexane at 140℃; for 24h; Molecular sieve; air;	97%

9,10-dihydroanthracene (613-31-0) + [(C12H8N2)2Mn(μ-O)2Mn(C12H8N2)2](ClO4)4 → [(1,10-phenanthroline)2Mn(η1-OClO3)2] (100685-12-9, 463965-74-4) + anthracene (120-12-7) + anthracen-9(10H)-one (90-44-8) + 9,10-phenanthrenequinone (84-65-1)

Conditions	Yield
In acetonitrile Kinetics; the soln. in acetonitrile was allowed to stand overnight at room temp.; the organic products were detected by GC/MS; the soln. was layered with ether;	A n/a B 97% C 0.8% D 2%

2-(2-benzylphenyl)-1,3-dioxolane → anthracene (120-12-7)

Conditions	Yield
With trifluorormethanesulfonic acid at 0 - 20℃; for 1h;	97%

9,10-dihydroanthracene (613-31-0) → anthracene (120-12-7) + 9,10-phenanthrenequinone (84-65-1)

Conditions	Yield
With tert.-butylhydroperoxide; H5PV2Mo10O40(1,11) In toluene for 24h; Ambient temperature;	A 96% B 4%
With dinitrogen monoxide; Ru(5,10,15,20-tetramesitylporphyrin)(O)2 In benzene at 200℃; under 7600 Torr; for 20h; Product distribution; Further Variations:; Solvents; Reagents; Temperatures;	A 9% B 90%
With dinitrogen monoxide; dioxo(tetramesitylporphyrinato)ruthenium(VI) In benzene at 200℃; under 7600 Torr; for 20h; Product distribution; Further Variations:; Reagents; Solvents; Temperatures;	A 9% B 90%

anthracen-9(10H)-one (90-44-8) → anthracene (120-12-7)

Conditions	Yield
aluminum oxide In isopropyl alcohol at 400℃; benzene as solvent;	95%
With iodine; magnesium In methanol at 20℃; for 3.5h;	94%
With sulfur In isopropyl alcohol at 400℃; for 5h;	90%

phenyl anthracene-9-carboxylate (1503-84-0) → anthracene (120-12-7)

Conditions	Yield
With nickel(II) acetate tetrahydrate; 1,2-bis-(dicyclohexylphosphino)ethane In toluene at 170℃; for 24h; Inert atmosphere; Glovebox; Sealed tube;	95%

9-cyanoanthracene (1210-12-4) → anthracene (120-12-7)

Conditions	Yield
With chloro(1,5-cyclooctadiene)rhodium(I) dimer; triisopropyl phosphite; chlorotriisopropylsilane In toluene at 160℃; for 15h; Inert atmosphere;	94%
With chloro(1,5-cyclooctadiene)rhodium(I) dimer; triisopropyl phosphite; chlorotriisopropylsilane In toluene at 160℃; for 15h; Inert atmosphere;	94%
Multi-step reaction with 2 steps 1: 12 percent / NH4Cl, NaN3 / dimethylformamide / 360 h / 90 °C 2: 9 percent / 600 °C / 0 - 0.1 Torr View Scheme
With [1,1'-bis(diphenylphosphino)ferrocene]nickel(II) chloride; ethanol; potassium hexamethylsilazane In toluene at 150℃; for 8h; Inert atmosphere;	62 %Spectr.

9-chloroanthracene (716-53-0) + 4,4,5,5-tetramethyl-[1,3,2]-dioxaboralane (25015-63-8) → anthracene (120-12-7)

Conditions	Yield
With dicyclohexyl-(2',6'-dimethoxybiphenyl-2-yl)-phosphane; tris-(dibenzylideneacetone)dipalladium(0); lithium chloride In toluene at 100℃; for 15h;	94%

9,10-dihydro-9,10-(2-phenyl-1-thiaethano)anthracene (84040-16-4) + 2,3-dimethyl-buta-1,3-diene (513-81-5) → anthracene (120-12-7) + 3,4-dimethyl-6-phenyl-5,6-dihydro-2H-thiopyran (84040-18-6)

Conditions	Yield
In toluene at 98 - 99℃; for 1h;	A 92% B 92%
Heating;	A 92% B 92%

o-benzylbenzylidene chloride (87619-43-0) → anthracene (120-12-7)

Conditions	Yield
at 475℃; under 0.1 Torr; flash vacuum pyrolysis;	91%

9,10-dihydroanthracen-9-ol (611-63-2) → anthracene (120-12-7) + anthracen-9(10H)-one (90-44-8) + 9,10-phenanthrenequinone (84-65-1)

Conditions	Yield
With aluminum oxide; Ru(OH)x; oxygen In para-xylene at 129.85℃; under 760 Torr; for 0.166667h;	A 91% B 7% C 2%

benzyl alcohol (100-51-6) + benzene (71-43-2) → anthracene (120-12-7)

Conditions	Yield
With aluminum (III) chloride at 60℃; for 3.5h;	90.3%
With aluminium trichloride at 60℃;
With aluminium trichloride

1-(chloromethyl)-2-(phenylmethyl)benzene (7510-28-3) → anthracene (120-12-7)

Conditions	Yield
at 575℃; under 0.1 Torr; flash vacuum pyrolysis;	90%

C18H14O (93103-39-0) → anthracene (120-12-7) + C18H14O (93103-38-9)

Conditions	Yield
With boron trifluoride In diethyl ether	A n/a B 90%

(9,10-dihydro-9,10-anthracenylene)-3a,6a-(4,5-dihydro-1H,3H-thieno<3,4-c>thiophene) (79482-99-8) → anthracene (120-12-7) + 4,5-dihydro-1H,3H-thieno<3,4-c>thiophene

Conditions	Yield
at 700℃; under 0.001 Torr;	A 90% B 83%

1,4-dihydro-1,4-epoxyanthracene (22187-13-9) → anthracene (120-12-7)

Conditions	Yield
With triphenyl phosphite; ammonium perrhenate In toluene at 80℃; for 18h; Inert atmosphere;	90%
With isopropylmagnesium bromide In tetrahydrofuran for 2h; Heating;	42%
Multi-step reaction with 2 steps 1: 95 percent / Mg / 10percent Pd/C / methanol / 25 °C 2: HCl gas / ethanol / 2 h / Heating View Scheme

anthracene (120-12-7) → 9,10-dihydroanthracene (613-31-0)

Conditions	Yield
With tetrabutylammonium tetrafluoroborate; water; lithium cation In N,N-dimethyl-formamide cathodic reduction;	100%
With tetraethylammonium bromide In ethanol at 60℃; electrolysis, lead cathode;	100%
With tetrabutylammonium tetrafluoroborate; water; lithium cation In N,N-dimethyl-formamide Product distribution; cathodic reduction; other hydroxy compounds, other solvent;	100%

anthracene (120-12-7) → 9-chloroanthracene (716-53-0)

Conditions	Yield
With chloro-trimethyl-silane; bis-[(trifluoroacetoxy)iodo]benzene In dichloromethane at 20℃; for 18h; Reagent/catalyst; Inert atmosphere;	100%
With Iodine monochloride In chloroform; acetonitrile for 3h;	98.1%
With N-chloro-succinimide; dimethyl sulfoxide In chloroform at 25℃; for 12h; Schlenk technique;	75%

anthracene (120-12-7) → 9-Bromoanthracene (1564-64-3)

Conditions	Yield
With bis(trifluoroacetoxy)iodobencene; trimethylsilyl bromide In dichloromethane at 20℃; Inert atmosphere;	100%
With N,N,N’,N’-tetrabromobenzene-1,3-disulfonamide In dichloromethane at 25℃; for 0.583333h;	98%
With copper(ll) bromide In chloroform Reflux;	94%

anthracene (120-12-7) → 9,10-Dibromoanthracene (523-27-3)

Conditions	Yield
With N-Bromosuccinimide; lithium perchlorate; silica gel In dichloromethane at 20℃; for 0.0833333h;	100%
With oxygen; 1,2-dibromomethane at 20℃; for 2h;	99%
With N-Bromosuccinimide; lithium perchlorate; silica gel In dichloromethane for 0.5h;	99%

anthracene (120-12-7) → 9,10-phenanthrenequinone (84-65-1)

Conditions	Yield
With nicotinium dichromate In acetic acid for 0.75h; Heating;	100%
With potassium bromate In acetic acid Heating;	100%
With ruthenium trichloride; dihydrogen peroxide; acetic acid	100%

4-Phenyl-1,2,4-triazolidine-3,5-dione (4233-33-4) + anthracene (120-12-7) → 9,10-(4’-phenyl)urazolo-9,10-dihydroanthracene (10316-56-0)

Conditions	Yield
In toluene at 20℃; for 2h;	100%
In chloroform-d1 at 25℃; Equilibrium constant; Temperature; Diels-Alder reaction; Darkness;	84 %Spectr.
In chloroform at 24.84℃; Kinetics; Solvent; Diels-Alder Cycloaddition;

1,4-anthraquinone (635-12-1) + anthracene (120-12-7) → C28H18O2 (13373-09-6, 137445-40-0)

Conditions	Yield
With aluminium trichloride In dichloromethane for 1h; Ambient temperature;	100%
With aluminium trichloride In dichloromethane Diels-Alder reaction;	87%
With zinc(II) chloride for 4.5h; Diels-Alder Cycloaddition; Sealed tube;	87%

anthracene (120-12-7) + (E)-But-2-enedioic acid methyl ester (1S,2R,3S,4R)-4,7,7-trimethyl-3-phenylcarbamoyloxy-bicyclo[2.2.1]hept-2-yl ester (76529-71-0) → C36H37NO6 (76529-77-6)

Conditions	Yield
With aluminium trichloride In dichloromethane at -30℃; for 24h;	100%

anthracene (120-12-7) → trans-9,10-bis(trichlorogermyl)-9,10-dihydroanthracene

Conditions	Yield
With oxygen; germanium hydride trichloride In benzene at 5℃; Product distribution; Mechanism;	100%

anthracene (120-12-7) + cyclohexa-1,3-diene (1165952-91-9) → dianthracene (1627-06-1)

Conditions	Yield
In benzene Irradiation;	100%

anthracene (120-12-7) + 1,6-bis(3,5-dioxo-1,2,4-triazoline4-yl)hexane (38727-98-9) → C38H32N6O4

Conditions	Yield
In dichloromethane for 0.5h; Ambient temperature;	100%

fumaryl dichloride (627-63-4) + anthracene (120-12-7) → 9,10-ethenoanthracene-trans-11,12-dicarboxylic acid dichloride

Conditions	Yield
In toluene for 4h; Diels-Alder Cycloaddition; Reflux;	100%
In toluene for 24h; Heating;	36%

anthracene (120-12-7) + 4-n-propyl-1,2,4-triazoline-3,5-dione (90046-99-4) → C19H17N3O2

Conditions	Yield
In dichloromethane for 4h; Ambient temperature;	100%

anthracene (120-12-7) + Phenyl[2-(trimethylsilyl)phenyl]iodonium trifluoromethanesulfonate → triptycene (477-75-8)

Conditions	Yield
With tetrabutyl ammonium fluoride In tetrahydrofuran; dichloromethane at 20℃; for 0.5h; cycloaddition; elimination;	100%

anthracene (120-12-7) + hexafluorothioacetone (1490-33-1) → C14H10SC(CF3)2 (1539-85-1)

Conditions	Yield
	100%
	100%

samarium (7440-19-9) + anthracene (120-12-7) → C14H10Sm

Conditions	Yield
With C2H4I2 In 1,2-dimethoxyethane activation of Sm with C2H4I2 soln. (2h,room temp.) , flask cooled to -20°C and charged with anthracene , after 2h reaction time the flask was warmed to room temp. and the mixt. stirred overnight ; suspension; not isolated , GC anal.;	100%

anthracene (120-12-7) + ytterbium → C14H10Yb (129823-92-3)

Conditions	Yield
With C2H4I2 In 1,2-dimethoxyethane activation of Yb with C2H4I2 soln. (2h,room temp.) , flask cooled to -20°C and charged with anthracene , after 2h reaction time the flask was warmed to room temp. and the mixt. stirred overnight ; suspension; not isolated , GC anal.;	100%

anthracene (120-12-7) + [(1,10-fc(NSitBuMe2)2)Y(THF)]2(μ-η3:η3-(E)-stilbene) → [(1,10-fc(NSitBuMe2)2)Y(THF)]2(μ-anthracene)

Conditions	Yield
In benzene-d6 at 70℃; for 1.16667h; Inert atmosphere; Schlenk technique;	100%

anthracene (120-12-7) + ethenetetracarbonitrile (670-54-2) → 2,2,3,3-Tetracyan-1,4-(o-phenylen)-tetralin

Conditions	Yield
at 20℃; for 0.0333333h; Diels-Alder Cycloaddition;	100%

(2,4-bis(2,6-diisopropylphenylimino)pentan-3-ide-.kappa2N,N')aluminum(I) (325465-25-6) + anthracene (120-12-7) → C43H51AlN2

Conditions	Yield
In benzene-d6 at 25 - 100℃; for 88h; Glovebox; Inert atmosphere;	100%

anthracene (120-12-7) + cyclohexa-1,3-diene (1165952-91-9) → C20H18 (63840-04-0)

Conditions	Yield
With C44H36B4F4N4O8S2 In dichloromethane at 20℃; for 12h; Reagent/catalyst; Inert atmosphere; Irradiation;	100%

Upstream product

• 100-41-4 ethylbenzene 
• 95-46-5 2-methylphenyl bromide 
• 4453-79-6 2-benzyl-1,3,5-trimethylbenzene 
• 4393-30-0 10,10′-tetrahydro-9,9′-dihydroxybianthryl 
• 108-24-7 acetic anhydride 
• 104-87-0 4-methyl-benzaldehyde 
• 71-43-2 benzene 
• 103-29-7 1,1'-(1,2-ethanediyl)bisbenzene 
• 46491-50-3 9,19-Dibromo-9,10-dihydroanthracene 
• 67-66-3 chloroform 
• 109-89-7 diethylamine 
• 67-72-1 hexachloroethane 
• 4462-90-2 naphthotropone 
• 84-65-1 9,10-phenanthrenequinone 

Downstream Products

• 5675-70-7 cis-9,10-dihydro-9,10-ethanoanthracene-11,12-diol cyclic carbonate 
• 5434-63-9 9,10-dihydro-9,10-ethanoanthracene-11-carboxylic acid 
• 217-59-4 triphenylene 
• 477-75-8 triptycene 
• 83742-19-2 trans-9,10-dihydro-9,10-ethano-anthracene-11,12-dicarboxylic acid (11,12)-diethyl ester 
• 1564-64-3 9-Bromoanthracene 
• 113951-44-3 11-phenyl-9,10-dihydro-9,10-ethano-anthracene-11,12-dicarboxylic acid-anhydride 
• 723-62-6 anthracen-9-carboxylic acid 
• 6373-11-1 aceanthrenequinone 
• 1210-12-4 9-cyanoanthracene 
• 91-20-3 naphthalene 
• 5675-64-9 9,10-ethanoanthracene 
• 642-31-9 9-anthracene aldehyde 
• 114553-29-6 (9,10-dihydro-9,10-ethano-anthracen-11-ylmethyl)-mesityl ether 

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Relevant articles and documents

In situelectrosynthesis of anthraquinone electrolytes in aqueous flow batteries

We demonstrate the electrochemical oxidation of an anthracene derivative to a redox-active anthraquinone at room temperature in a flow cell without the use of hazardous oxidants or noble metal catalysts. The anthraquinone, generatedin situ, was used as the active species in a flow battery electrolyte without further modification or purification. This potentially scalable, safe, green, and economical electrosynthetic method is also applied to another anthracene-based derivative and may be extended to other redox-active aromatics.

Photochemistry of 9-Benzoylanthracene

Photoexcitation of 9-benzoylanthracene (1) in toluene solution under argon results in head-to-tail dimerization by 4? + 4? cycloaddition to give dibenzoyl-substituted dianthracene in about 60percent yield.The concomitant formation of both anthracene and 9,10-dibenzoylanthracene (ca. 4percent yield) suggests that intermolecular benzoyl group/hydrogen exchange may be an inefficient mode of deactivation the intermediate excimer.Irradiation of crystalline 1 gave the head-to-tail dimer, without byproducts, in a maximal yield of 50percent.It was established by X-ray diffraction that theasymmetric unit of 1 consists of two molecules, 1A and 1B, in which the carbonyl group is twisted out of the plane of the anthracene by 67.4 deg and 86.5 deg, respectively.Investigation of the packing pattern revealed that only parallel overlapping head-to-tail oriented molecules of 1A, characterized by an interplanar spacing of 3.35 Angstroem, can undergo photochemical dimerization by 4? + 4? cycloaddition.The spatial relation of adjacent molecules of 1B is such as to preclude their involvement in the photochemical dimerization.

Stoichiometric Formation of an Oxoiron(IV) Complex by a Soluble Methane Monooxygenase Type Activation of O2 at an Iron(II)-Cyclam Center

In soluble methane monooxygenase enzymes (sMMO), dioxygen (O2) is activated at a diiron(II) center to form an oxodiiron(IV) intermediate Q that performs the challenging oxidation of methane to methanol. An analogous mechanism of O2 activation at mono-or dinuclear iron centers is rare in the synthetic chemistry. Herein, we report a mononuclear non-heme iron(II)-cyclam complex, 1-trans, that activates O2 to form the corresponding iron(IV)-oxo complex, 2-trans, via a mechanism reminiscent of the O2 activation process in sMMO. The conversion of 1-trans to 2-trans proceeds via the intermediate formation of an iron(III)-superoxide species 3, which could be trapped and spectroscopically characterized at-50 °C. Surprisingly, 3 is a stronger oxygen atom transfer (OAT) agent than 2-trans; 3 performs OAT to 1-trans or PPh3 to yield 2-trans quantitatively. Furthermore, 2-trans oxidizes the aromatic C-H bonds of 2,6-di-tert-butylphenol, which, together with the strong OAT ability of 3, represents new domains of oxoiron(IV) and superoxoiron(III) reactivities.

Indium-catalyzed construction of polycyclic aromatic hydrocarbon skeletons via dehydration

Polycyclic aromatic compounds can be synthesized from 2-benzylic- or 2-allylbenzaldehydes using a catalytic amount of In(III) or Re(I) complexes. By using this method, polycyclic aza-aromatic compounds can also be prepared efficiently. In these reactions, only water is formed as a side product.

Synthesis and Pyrolysis of a Triafulvene Precursor

In view of retro-Diels-Alder reactions (RDA reactions), the triafulvene precursor 3 has been prepared in a simple three-step synthesis by dibromocarbene addition at dibenzo-barralene (11-->12; 44percent), halogen-Li exchange followed by methylation (12-->14, 100percent) and HBr elimination (14-->3, 62percent) Scheme 3).Reactivity of the so far unknown bridged 1,1-dibromocyclopropane 12 has been explored, including reductions, allylic rearrangements, and "carbene dimerizations" (Scheme 4).First experiments with respect to the thermal behaviour of 3 show that RDA reaction, although occuring in most cases, is not the predominant pathway.When 3 is heated in a sealed tube without solvent, two dimers 26 and 27 are isolated in a total yield of 55percent (Scheme 6).On the other hand, gas-phase pyrolysis of 3 at 400 deg mainly produces rearranged 28 (56percent; Scheme 7).It is assumed that bridged trimethylenemethane 29 is an essential intermediate in thermal rearrangements of 3 (Scheme 8).

Evaluation of the Transferability of the “Flexible Steric Bulk” Concept from N-Heterocyclic Carbenes to Planar-Chiral Phosphinoferrocenes and their Electronic Modification

The concept of “flexible steric bulk” is discussed at 2-phenylvinyl-1-phosphinoferrocenes. The introduction of freely rotatable 1'-silyl groups increases the catalytic productivity within the synthesis of tri-ortho-substituted biaryls by Suzuki–Miyaura C,C cross-coupling reactions, giving higher yields with 1/4 of catalyst concentration than for the non-silylated derivatives. Electronic modification of the P and the vinyl donor functionalities was investigated by introducing substituents in the para positions of both groups. Therein, electron-withdrawing phosphines increased the yield from 78 to 91 percent for a given biaryl, by changing from a diphenylphosphino to the P(p-CN-C6H4)2 unit. Opposite results, obtained from electron-donating and sterically demanding phosphines, were in accordance with the 1J(31P,77Se) values. However, the electron density of the ferrocenyl backbone, expressed by the redox potential of the first ferrocenyl-related redox process, cannot be correlated with the donor-properties at the P atom. Changing from a PPh2-substituted ferrocene to a (RA)-1,1'-binaphthyl-containing phosphonite, a complex interaction between the axial- and the planar-chiral motifs occurs, resulting a change of the absolute biaryl configuration.

The effect of oils on PAH, PCDD, PCDF, and PCB emissions from a spark engine fueled with leaded gasoline

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OXIDATION OF ARENES BY MOLTEN GALLIUM(III) CHLORIDE

Molten, anhydrous Ga2Cl6 at 100-130 deg C readily oxidizes pyrene, anthracene and naphthacene with the concomitant reduction of Ga(III) to Ga(I).Dilute solutions of these arenes (ArH) are oxidized to their radical cations (ArH+.), wich decay very slowly in Ga2Cl6, while more concentrated solutions are oxidized to stable arenium ions (ArH2+) with hydrogen derived from aryl-aryl coupling reactions.

Metal organic frameworks as efficient heterogeneous catalysts for the oxidation of benzylic compounds with t-butylhydroperoxide

Iron and copper metal organic frameworks of 1,3,5-benzenetricarboxylate [Fe(BTC) and Cu3(BTC)2] are efficient and reusable solid catalysts for the oxidation of benzylic compounds with t-butylhydroperoxide as oxidant in acetonitrile with moderate to good yields. The solids were stable under the reaction conditions as confirmed by comparison of the powder XRD of the fresh and reused catalysts. EPR spectroscopy using diphenyl-N-t-butyl nitrone as spin trap has allowed to detect C-centered radicals as reaction intermediates.

9,10-Dehydroanthracene: p-Benzyne-type biradicals abstract hydrogen unusually slowly

The 9,10-dehydroanthracene biradical, a model for the p-benzyne-type biradicals implicated in DNA cleavage by the enediyne antitumor antibiotics, was prepared by photodissociation of a propellane in solution. Trapping products characteristic of biradicals, e.g. anthracene-d2, are found. The rates of hydrogen abstraction by the biradical from acetonitrile and isopropyl alcohol are measured directly by flash photolysis/transient absorption spectroscopy, giving second-order rate constants of k(MeCN,abstr) = (1.1 ± 0.2) x 103 M-1 s-1 and k(i-PrOH,abstr) = (6.5 ± 0.6) x 103 M-1 s-1 at room temperature, which are 100-200 times lower than the corresponding rate constants for phenyl or 9-anthryl radical. A second decay route for the biradical is found, and assigned, based on thermochemical, kinetic, and trapping arguments to a retro-Bergman reaction that converts the 9,10-dehydroanthracene biradical into the ring-opened 3,4-benzocyclodeca-3,7,9-triene-1,5-diyne. Although the retro-Bergman reaction is relatively fast, k ~ 4 x 105 s-1 at room temperature, it is competitive with hydrogen abstraction by the biradical only because the hydrogen abstraction is slower than expected. Through-bond coupling in the 1,4-biradical is discussed as a rationalization for the 100- to 200-fold reduction in the abstraction rate.

Photochemical Debromination of Meso-Substituted Bromoanthracenes Studied by Steady-State Photolysis and Laser Photolysis

Debrominations of 9-bromoanthracene (BA) and 9,10-dibromoanthracene (DBA) in acetonitrile containing triethylamine (TEA) or N,N-dimethylaniline (DMA) have been studied by means of steady-state photolysis and laser photolysis.By the addition of TEA, the decay constants of the lowest excited singlet states of BA and DBA increase and the maximum yields of the triplet states decrease.The singlet quenching rate constants by TEA are calculated to be of the order of 1E10 M-1 s-1, showing that the reactions are diffusion controlled.Compared with the result of γ-radiolysis and pulse radiolysis, it is suggested that the photochemical debrominations of BA and DBA in the presence of amines take place via the anion radicals which are produced through exciplexes between amines and the lowest excited singlet states of bromoanthracenes.

Reactivity of bio-inspired Cu(II) (N2/Py2) complexes with peroxide at room temperature

Developing coordination complexes of earth abundant metals that can perform substrate oxidations under benign conditions is an ongoing challenge. Herein, the reactivity of two mononuclear Cu-complexes toward the oxidant H2O2 is reported. Both complexes displayed ligand oxidation upon reaction with the oxidant. Analysis of spectroscopic data established that the respective product complexes contained mononuclear Cu(II) centers. Moreover, treatment of these Cu-complexes with oxidant in the presence of substrate resulted in the interception of ligand oxidation with preferential oxidation of the substrate. Computational studies identified plausible mechanistic pathways, suggesting a copper-oxyl intermediate as the likely reactive intermediate responsible for substrate and ligand oxidation. To our knowledge, this is the first Cu-mediated system that showed ligand oxidation, oxo-transfer capability, and external hydrocarbon oxidation under stoichiometric conditions.

Metal-Free Selective Borylation of Arenes by a Diazadiborinine via C-H/C-F Bond Activation and Dearomatization

A newly developed annulated 5-chlorinated 1,3,2,5-diazadiborinine derivative (4) selectively activates a C-H bond of benzene (C6H6) and 1,3-di(trifluoromethyl)benzene, as well as a C-F bond in partially fluorinated arenes, to furnish borylation products under catalyst-, metal-, and irradiation-free conditions. Moreover, 4 readily undergoes a reversible dearomative coupling reaction with polycyclic aromatic hydrocarbons to afford diboration products. The latter represents the first reversible intermolecular dearomative diboration of arenes.

Dioxygen Activation by a Hexagonal SrMnO3 Perovskite Catalyst for Aerobic Liquid-Phase Oxidation

Heterogeneous catalysts, which allow a reductive activation of dioxygen (O2) under mild reaction conditions, are promising candidates for highly efficient aerobic oxidation. An effective hexagonal SrMnO3 (SMO) perovskite catalyst for liquid-phase selective oxidation with O2 was successfully synthesized by the polymerized complex method. The activity of SMO for the aerobic oxidation of alcohols was higher than those of typical manganese oxide-based catalysts and was heterogeneous, so that the recovered catalyst could be reused without heat treatment under oxidative conditions while keeping its high catalytic performance. The reversible reaction on the surface Mn species on SMO with O2 leads to the formation of Mn–superoxo species, which catalyze the selective oxidative transformation of various types of organic substrates into the desired oxygenated or dehydrogenated products.

Stabilizing Terminal Ni(III)-Hydroxide Complex Using NNN-Pincer Ligands: Synthesis and Characterization

The reaction of [Ni(COD)2] (COD; cyclooctadiene) in THF with the NNN-pincer ligand bis(imino)pyridyl (L1) reveals a susceptibility to oxidation in an inert atmosphere ([O2] level III(L1··)2-(OH)] (1). Various isotopically labeled experiments (16O/18O) assertively endorse the origin of terminal oxygen based ligand in 1 due to the activation of molecular dioxygen. The presence of proton bound to the terminal oxygen in 1 is well supported by NMR, IR spectroscopy, DFT calculations, and hydrogen atom transfer (HAT) reactions promoted by 1. The observation of shakeup satellite peaks for the primary photoelectron lines of Ni(2p) in the X-ray photoelectron spectroscopy (XPS) unambiguously confirms the paramagnetic signature associated with the distorted square planar nickel ion, which is consistent with the trivalent oxidation state assigned for the nickel ion in 1. The variable temperature magnetic susceptibility data of 1 shows dominant antiferromagnetic interactions exist among the paramagnetic centers, resulting in an overall S = 1/2 ground state. Variable temperature X-band EPR studies performed on 1 show evidence for the S = 1/2 ground state, which is consistent with magnetic data. The unusual g-tensor extracted for the ground state S = 1/2 is analyzed under a strong exchange limit of spin-coupled centers. The electronic structure predicted for 1 is in good agreement with theoretical calculations.

Pd(II) Coordination Sphere Engineering: Pyridine Cages, Quinoline Bowls, and Heteroleptic Pills Binding One or Two Fullerenes

Fullerenes and their derivatives are of tremendous technological relevance. Synthetic access and application are still hampered by tedious purification protocols, peculiar solubility, and limited control over regioselective derivatization. We present a modular self-assembly system based on a new low-molecular-weight binding motif, appended by two palladium(II)-coordinating units of different steric demands, to either form a [Pd2L14]4+ cage or an unprecedented [Pd2L23(MeCN)2]4+ bowl (with L1 = pyridyl, L2 = quinolinyl donors). The former was used as a selective induced-fit receptor for C60. The latter, owing to its more open structure, also allows binding of C70 and fullerene derivatives. By exposing only a fraction of the bound guests' surface, the bowl acts as fullerene protecting group to control functionalization, as demonstrated by exclusive monoaddition of anthracene. In a hierarchical manner, sterically low-demanding dicarboxylates were found to bridge pairs of bowls into pill-shaped dimers, able to host two fullerenes. The hosts allow transferring bound fullerenes into a variety of organic solvents, extending the scope of possible derivatization and processing methodologies.

A Highly Reactive Seven-Coordinate Osmium(V) Oxo Complex: [OsV(O)(qpy)(pic)Cl]2+

Seven-coordinate ruthenium oxo species have been proposed as active intermediates in catalytic water oxidation by a number of highly active ruthenium catalysts, however such species have yet to be isolated. Reported herein is the first example of a seven-coordinate group 8 metal-oxo species, [OsV(O)(qpy)(pic)Cl]2+ (qpy=2,2′:6′,2″:6″,2-quaterpyridine, pic=4-picoline). The X-ray crystal structure of this complex shows that it has a distorted pentagonal bipyramidal geometry with an Os=O distance of 1.7375 ?. This oxo species undergoes facile O-atom and H-atom-transfer reactions with various organic substrates. Notably it can abstract H atoms from alkylaromatics with C-H bond dissociation energy as high as 90 kcal mol-1. This work suggests that highly active oxidants may be designed based on group 8 seven-coordinate metal oxo species.

Base-Free Palladium-Catalyzed Borylation of Aryl Chlorides with Diborons

The base-free palladium-catalyzed borylation of aryl chlorides with diborons was achieved. The base-free conditions offered acceptable functional group compatibility. Based on experimental and computational studies, it was shown that smooth boryl transfer from the diborons to the arylpalladium chloride was promoted by strong interaction between the Lewis acidic boron and the chlorine atom on palladium.

Alkaline Earth Metal-Ammonia-Anion Radical Complexes

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C(sp3)-H Fluorination with a Copper(II)/(III) Redox Couple

Despite the growing interest in the synthesis of fluorinated organic compounds, few reactions are able to incorporate fluoride ions directly into alkyl C-H bonds. Here, we report the C(sp3)-H fluorination reactivity of a formally copper(III) fluoride complex. The C-H fluorination intermediate, LCuF, along with its chloride and bromide analogues, LCuCl and LCuBr, were prepared directly from halide sources with a chemical oxidant and fully characterized with single-crystal X-ray diffraction, X-ray absorption spectroscopy, UV-vis spectroscopy, and 1H nuclear magnetic resonance spectroscopy. Quantum chemical calculations reveal significant halide radical character for all complexes, suggesting their ability to initiate and terminate a C(sp3)-H halogenation sequence by sequential hydrogen atom abstraction (HAA) and radical capture. The capability of HAA by the formally copper(III) halide complexes was explored with 9,10-dihydroanthracene, revealing that LCuF exhibits rates 2 orders of magnitude higher than LCuCl and LCuBr. In contrast, all three complexes efficiently capture carbon radicals to afford C(sp3)-halogen bonds. Mechanistic investigation of radical capture with a triphenylmethyl radical revealed that LCuF proceeds through a concerted mechanism, while LCuCl and LCuBr follow a stepwise electron transfer-halide transfer pathway. The capability of LCuF to perform both hydrogen atom abstraction and radical capture was leveraged to enable fluorination of allylic and benzylic C-H bonds and α-C-H bonds of ethers at room temperature.

Non-heme iron(ii/iii) complexes that model the reactivity of lipoxygenase with a redox switch

Three ferrous/ferric complexes of a N6 hexadentate ligand, N,N,N′,N′-tetrakis(2-benzimidazolyl-methyl)ortho-diamine-trans- cyclohexane (ctb), [FeII(ctb)](ClO4)2· EtOH (1), [FeIII(OEt)(Hctb)](ClO4)3·EtOH (2), and [FeIII(OMe)(Hctb)](ClO4)3· 3MeOH·4.5H2O (3), were synthesized and characterized as models of lipoxygenase. The lipoxygenase activities of the complexes were checked and the results indicate that ferrous complex 1 is inactive while ferric alkoxide complexes 2 and 3 show catalytic activity via the hydrogen atom abstraction reaction mechanism.

Spectroscopic capture and reactivity of a low-spin cobalt(IV)-oxo complex stabilized by binding redox-inactive metal ions

High-valent cobalt-oxo intermediates are proposed as reactive intermediates in a number of cobalt-complex-mediated oxidation reactions. Herein we report the spectroscopic capture of low-spin (S=1/2) CoIV-oxo species in the presence of redox-inactive metal ions, such as Sc3+, Ce3+, Y3+, and Zn2+, and the investigation of their reactivity in C-H bond activation and sulfoxidation reactions. Theoretical calculations predict that the binding of Lewis acidic metal ions to the cobalt-oxo core increases the electrophilicity of the oxygen atom, resulting in the redox tautomerism of a highly unstable [(TAML)CoIII(O.)]2- species to a more stable [(TAML)CoIV(O)(Mn+)] core. The present report supports the proposed role of the redox-inactive metal ions in facilitating the formation of high-valent metal-oxo cores as a necessary step for oxygen evolution in chemistry and biology. What is the metal's role? Cobalt(IV)-oxo complexes binding redox-inactive metal ions, such as Sc3+, Ce3+, Y3+, and Zn2+, are investigated in oxygenation reactions. Theory predicts that the binding of metal ions to the cobalt-oxo core increases the electrophilicity of the oxygen atom. This result supports the role of redox-inactive metal ions in facilitating the formation of high-valent metal-oxo cores as a necessary step for oxygen evolution in chemistry and biology. CAN=cerium ammonium nitrate.

Investigating reactivity and electronic structure of copper(II)-polypyridyl complexes and hydrogen peroxide

This work presents a detailed study of the reactivity of three mononuclear CuII complexes supported by derivatives of the tetradentate ligand N,N'-bis(2-pyridylmethyl)-1,2-ethylenediamine (bispicen). The CuII complexes are capable of performing C[sbnd]H bond activation in the presence of NEt3 and H2O2 through what has been proposed computationally to be a [CuO]+ intermediate. A wavefunction-based quantum chemical investigation into the electronic structure of the proposed [CuO]+ intermediate reveals a triplet ground state predominantly consistent with an S = ? CuII center ferromagnetically coupled to an oxyl radical, though contributions from the corresponding biradicaloid CuI-oxene resonance structure may be nontrivial. Furthermore, correlation of the electronic structure of the proposed intermediate with analogous high-valent metal-oxo species capable of olefin epoxidation suggests that the CuII complexes might be also capable of olefin epoxidation in the presence of NEt3 and H2O2. To test this hypothesis experimentally, the CuII complexes are treated with NEt3 and H2O2 in the presence of alkene substrates, resulting in the formation of epoxides.

A Bottleable Imidazole-Based Radical as a Single Electron Transfer Reagent

Reduction of 1,3-bis(2,6-diisopropylphenyl)-2,4-diphenyl-1H-imidazol-3-ium chloride (1) resulted in the formation of the first structurally characterized imidazole-based radical 2. 2 was established as a single electron transfer reagent by treating it with an acceptor molecule tetracyanoethylene. Moreover, radical 2 was utilized as an organic electron donor in a number of organic transformations such as in activation of an aryl-halide bond, alkene hydrosilylation, and in catalytic reduction of CO2 to methoxyborane, all under ambient temperature and pressure.

Metal-Free Heterogeneous Semiconductor for Visible-Light Photocatalytic Decarboxylation of Carboxylic Acids

A suitable protocol for the photocatalytic decarboxylation of carboxylic acids was developed with metal-free ceramic boron carbon nitrides (BCN). With visible light irradiation, BCN oxidize carboxylic acids to give carbon-centered radicals, which were trapped by hydrogen atom donors or employed in the construction of the carbon-carbon bond. In this system, both (hetero)aromatic and aliphatic acids proceed the decarboxylation smoothly, and C-H, C-D, and C-C bonds are formed in moderate to high yields (35 examples, yield up to 93%). Control experiments support a radical process, and isotopic experiments show that methanol is employed as the hydrogen atom donor. Recycle tests and gram-scale reaction elucidate the practicability of the heterogeneous ceramic BCN photoredox system. It provides an alternative to homogeneous catalysts in the valuable carbon radical intermediates formation. Moreover, the metal-free system is also applicable to late-stage functionalization of anti-inflammatory drugs, such as naproxen and ibuprofen, which enrich the chemical toolbox.