- Radical Cations of Benzopyrene and 6-Substituted Derivatives: Synthesis and Reaction with Nucleophiles
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Radial cations of benzopyrene (BP) and 6-substituted derivatives were synthesized by two methods: reaction of the hydrocarbon with I2 and AgClO4 in benzene, and reaction of the hydrocarbon with NOBF4 in CH3CN/CH2Cl2.Both the radical cation perchlorates and tetrafluoroborates were stable for prolonged periods of time when stored under argon at subzero temperatures.The radical cations were reacted with nucleophiles of various strengths, namely H2O, AcO(1-) and F(1-), as a means of best characterizing these intermediates, as well as determining their chemical properties.Reaction of BP, 6-FBP, 6-ClBP, and 6-BrBP radical cation perchlorates with H2O produced BP 1,6-, 3,6-, and 6,12-dione, whereas the radical cation derived from 6-CH3BP yielded 6-CH2OHBP.When BP(.1+)ClO4(1-) and 6-FBP(.1+)ClO4(1-) were reacted with NaOAc in H2O/CH3CN (9:1), 6-OAcBP was formed, in addition to the quinones. 6-ClBP(.1+)ClO4(1-) formed a small amount of 1-OAc-6-ClBP and 3-OAc-6-ClBP, in addition to the diones, whereas for 6-BrBP(.1+)ClO4(1-) and 6-CH3BP(.1+)ClO4(1-) the reaction products were BP diones and 6-CH2OHBP, respectively.Reactions conducted under anhydrous conditions, using tetramethylammonium acetate in CH3CN, gave similar results, except that no quinones were formed.These results confirm the reactivity of nucleophiles at the postions of high charge localization in the BP(.1+), i.e.C-6, followed by C-1 and C-3.
- Cremonesi, Paolo,Stack, Douglas E.,Rogan, Eleanor G.,Cavalieri, Ercole L.
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- POLYCYCLIC AROMATIC HYDROCARBON-BASED COMPOUNDS FOR MOLECULAR ELECTRONIC DEVICE AND MOLECULAR ELECTRONIC DEVICES COMPRISING SAME
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The present invention relates to polycyclic aromatic hydrocarbon-based compounds, for a molecular electronic device, enabling molecular rectification, and molecular electronic devices comprising a molecular layer formed by means of the compounds self-assembled on an electrode. The compounds according to the present invention can realize rectifying properties by being introduced between electrodes and thus enable a high rectification ratio by means of low voltage driving, and thus can be substituted for a silicon-based diode device and, more particularly, can be utilized for a wearable device, Bluetooth, an IoT enabling device and the like which require low voltage driving.
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Paragraph 0093-0097
(2021/11/26)
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- Synthesis and optical properties of the C-8 adduct of benzo[a]pyrene and deoxyguanosine
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8-(Benzo[a]pyren-6-yl)-2′-deoxyguanosine (Bp-dG) was prepared via a palladium-catalyzed Suzuki-Miyaura-type cross-coupling reaction from the pinacol ester of 6-benzo[a]pyrenyl boronic acid and the corresponding brominated deoxyguanosine precursor. The absorption and steady-state fluorescence properties of Bp-dG were characterized and compared with that of 6-benzo[a]pyrene. The modified nucleoside Bp-dG exhibits an unexpected high stability towards nucleosidic hydrolysis even under irradiation with UV light. Georg Thieme Verlag Stuttgart.
- Valis, Linda,Wagenknecht, Hans-Achim
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p. 2281 - 2284
(2007/10/03)
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- One-Electron Oxidation of 6-Substituted Benzopyrenes by Manganic Acetate. A Model for Metabolic Activation
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Radical cations of benzopyrene (BP) and 6-substituted derivatives were generated by one-electron oxidation with 2 equiv of Mn(OAc)3*2H2O.Some of the properties of these radical cations were investigated by nucleophilic trapping with acetate ion.BP produced predominantly 6-OAcBP and small amounts of BP 1,6-, 3,6-, and 6,12-dione. 6-FBP yielded 6-OAcBP, a mixture of 1,6-(OAc)2BP and 3,6-(OAc)2BP, and BP diones.In the case of 6-ClBP and 6-BrBP the major products obtained were a mixture of the 1-OAc and 3-OAc derivatives, and BP diones, while substantial starting material remained unreacted. 6-CH3BP afforded mostly 6-OAcCH2BP, a mixture of 1-OAc and 3-OAc derivatives of 6-CH3BP, and a mixture of 1-OAc and 3-OAc derivatives of 6-OAcCH2BP.These results indicate that nucleophilic substitution of BP-radical-cation and 6-FBP-radical-cation occurs exclusively at C-6.For 6-ClBP-radical-cation and 6-BrBP-radical-cation substitution at C-1 and C-3, which are the positions of second highest charge density in their radical cations after C-6, complete successfully for nucleophilic substitution.For 6-CH3BP-radical-cation charge localization at C-6 activates the methyl group rendering it the most reactive toward nucleophilic attack.Competitive acetoxylation of 6-CH3BP-radical-cation also occurs to a minor extent at C-1 and C-3.These mechanistic studies have been useful in clarifying some aspects of the metabolism of BP and its halogeno derivatives by cytochrome P-450 and peroxidases.Furthermore, this chemistry can provide some guidance in understanding the mechanism of tumor initiation by these compounds.
- Cremonesi, Paolo,Cavalieri, Ercole L.,Rogan, Eleanor G.
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p. 3561 - 3570
(2007/10/02)
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- Policyclic Fluoranthene Hydrocarbons. 2. A New General Synthesis
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A novel and efficient synthetic approach to policyclic fluoranthene hydrocarbons is described.The method entails fusion of an indeno ring to an appropriate alternant hydrocarbon via reaction of its aryllithium derivative with cyclohexene oxide, followed by oxidation, cyclodehydration, and aromatization.Cyclization of the cyclohexanone and cyclohexanol derivatives of the policyclic aromatic ring systems studied proceeds with high regioselectivity, and the direction of ring closure is predictable by molecular orbital methods.This synthetic approach provides a convenient general route to polyaromatic fluoranthene compounds, including potentially carcinogenic members of this class.Hydrocarbons synthesized by this method include benzacephenanthrylene (1), indenopyrene (2), indenochrysene (3), benzindenochrysene (4), fluorenochrysene (5), dibenzaceanthrylene (6), dibenzaceanthrylene (7), benzaceanthrylene (8), benzindenochrysene (9), fluorenochrysene (10), and dibenzacephenanthrylene (11).
- Cho, Bongsup P.,Harvey, Ronald G.
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p. 5668 - 5678
(2007/10/02)
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