Lewis Acid-Assisted Nucleophilic Substitution of Fullerene Epoxide

Tajima, Yusuke; Hara, Takumi; Honma, Takeshi; Matsumoto, Shiro; Takeuchi, Kazuo

doi:10.1021/ol0610183

Cited by 65 publications

(51 citation statements)

References 27 publications

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“…[36][37][38][39] The absorption peaks around 430 nm are slightly red-shifted from those of PCBM. Additionally, the bis-and trisadducts showed broader absorptions as a result of the fact that they are a mixture of regioisomers.…”

Section: Photophysical Propertiesmentioning

confidence: 97%

Cyclobutadiene–C₆₀ Adducts: N‐Type Materials for Organic Photovoltaic Cells with High V_OC

Han¹,

Collins²,

Andrew³

et al. 2013

Adv Funct Materials

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We have developed new tetraalkylcyclobutadiene-C 60 adducts, via Diels-Alder cycloaddition of C 60 with in situ generated cyclobutadienes. The cofacial π-orbital interactions between the fullerene orbitals and the cyclobutene are shown to decrease the electron affinity and thereby increase the LUMO energy level of C 60 significantly (ca. 100 meV and 300 meV for mono-and bisadducts, respectively). These variations in LUMO levels of fullerene can be used to generate higher open-circuit voltages (V OC ) in bulk heterojunction polymer solar cells. The tetramethylcyclobutadiene-C 60 monoadduct displays an open-circuit voltage (0.61V) and a power conversion efficiency (2.49%) comparable to the widely used P3HT/PCBM composite (0.58V and 2.57% respectively). The role of the cofacial π-orbital interactions between C 60 and the attached cyclobutene group was probed chemically by epoxidation of the cyclobutene moiety and theoretically through density functional theory (DFT) calculations. The electrochemical, photophysical, and thermal properties of the newly synthesized fullerene derivatives support the proposed effect of functionalization on electron affinities and photovoltaic performance.

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Section: Photophysical Propertiesmentioning

confidence: 97%

Cyclobutadiene–C₆₀ Adducts: N‐Type Materials for Organic Photovoltaic Cells with High V_OC

Han¹,

Collins²,

Andrew³

et al. 2013

Adv Funct Materials

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“…+ intermediate (Scheme 1); 20 2) reaction of C 60 with arylhydrazine and sodium nitrite producing 1,4-C 60 Ar(OH), 21 which react with arenes in the presence of p-toluenesulfonic acid giving 1,4-C 60 Ar 2 (Scheme 2); 22 3) hydroarylation reaction of C 60 in the presence of trichloroaluminum and a small amount of water giving C 60 Ar 2 H 2 , 23 which is deprotonated by base, followed by oxidation of the resulting fullerene anions by copper(I) salt to produce 1,4-C 60 Ar 2 (Scheme 3); 24 4) rhodiumcatalyzed addition reaction of arylboronic acids to C 60 producing monoadducts C 60 ArH, 25 which undergo palladium-catalyzed cross-coupling reaction with aryl halide to obtain 1,4-C 60 Ar 2 (Scheme 4). 26 Although diarylfullerene is a stable compound, its performance as an electron-acceptor in organic thin-film solar cells is limited.…”

Section: ç Improvement Of Open-circuit Voltage By Installation Of Elementioning

confidence: 99%

Design Concept for High-LUMO-level Fullerene Electron-acceptors for Organic Solar Cells

Matsuo

2012

Chemistry Letters

113

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This review article describes design concept, synthesis, and features of fullerene derivatives having high lowest unoccupied molecular orbital (LUMO) levels to achieve high open-circuit voltage in organic thin-film photovoltaic devices. Installation of organic electron-donating groups onto fullerene and decrease of the size of the fullerene ³-electron-conjugated system raise the LUMO levels, affording high-performance organic solar cells. Addition of the methano group as the smallest carbon addend to fullerene to obtain 56³-electron fullerene derivatives is likely a promising strategy for this purpose. Ç IntroductionOrganic thin-film solar cells are lightweight and flexible, and thus are expected to allow for low-cost production through a printing process. 1 The active layer that converts light into electricity contains organic semiconductors, whose development is the key to improving power conversion efficiency. Accordingly, organic chemistry has a major role to play. Up to now, the development of organic thin-film solar cells has been led by material scientists and device engineers, but there is increasing demand for collaboration with synthetic chemists who can design and synthesize organic semiconductor molecules.Although the power conversion efficiency of organic thinfilm solar cells was about 1% before 2000, a sharp increase in conversion efficiency was seen after 2000, owing to the discovery of the combination of poly(3-hexylthiophene) (P3HT; an organic electron-donor) and phenyl-C 61 -butyric acid methyl ester (PCBM; an organic electron-acceptor).2 When heated and exposed to solvent vapor, P3HT undergoes self-assembly and forms ³-stacked structures, improving its electrical properties and light absorption characteristics. Furthermore, PCBM is a fullerene derivative that is soluble in organic solvents, and its solubility allows for blend solutions containing P3HT to be prepared over a range of concentrations. Furthermore, thin films prepared through the use of a P3HT/PCBM blend solution have made it possible to develop composite films with a bulk heterojunction structure, in which an electron-donor and an electron-acceptor are suitably mixed.3 In comparison with conventional pn heterojunction devices, bulk heterojunction devices have a greater interface area between the donor and acceptor and charge separation is more efficient. In this way, around 2005, power conversion efficiency reached 45%. 4 In the last few years, the power conversion efficiency of organic thin-film solar cells has increased further to about 10%. 5This vast improvement was largely due to the development of new materials, for example, new electron-donors such as low band gap polymers, 6 which are capable of absorbing longwavelength light. These materials are alternating copolymers with electron-rich and electron-deficient parts, and for this reason they have high-lying HOMO and low-lying LUMO levels. Intermolecular charge transfer from electron-rich parts to electron-deficient parts makes such materials capable of absorbing...

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“…For example, fullerene epoxide, [4] with a highly reactive three-membered ring, has been used as a reactive candidate to obtain structurally-defined biaryl- [5] and cycloaminofullerenes. [6] However, the initial epoxidation of fullerene by photooxy-…”

Section: Introductionmentioning

confidence: 99%

Notably Enhanced Reactivity of the Fulleroid anti‐Bredt Double Bond in Diels–Alder Reactions

2011

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(3d) and 2-methylbutadiene (3e)] has been carried out in toluene at 30°C. Notably, the relative rate ratio k/k 0 for each dienophile (vs. C 60 ) was remarkably dependent on the diene used; the less hindered H/CN fulleroids 1a and 1b became 25-104 times more reactive than C 60 with conformationally flexible dienes such as 3d and 3e. These fulleroids, however, showed similar or rather diminished reactivity with rigid 3a and 3b. In contrast,

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Lewis Acid-Assisted Nucleophilic Substitution of Fullerene Epoxide

Abstract: [Structure: see text] A 1,4-bis(phenyl)-1,4-dihydro[60]fullerene resulting from an efficient nucleophilic substitution has been obtained by reaction of a fullerene epoxide, C60O, with nucleophilic aromatic compounds in the presence of boron trifluoride etherate as a Lewis acid.

Cited by 65 publications

References 27 publications

Cyclobutadiene–C₆₀ Adducts: N‐Type Materials for Organic Photovoltaic Cells with High V_OC

Cyclobutadiene–C₆₀ Adducts: N‐Type Materials for Organic Photovoltaic Cells with High V_OC

Design Concept for High-LUMO-level Fullerene Electron-acceptors for Organic Solar Cells

Notably Enhanced Reactivity of the Fulleroid anti‐Bredt Double Bond in Diels–Alder Reactions

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Lewis Acid-Assisted Nucleophilic Substitution of Fullerene Epoxide

Abstract: [Structure: see text] A 1,4-bis(phenyl)-1,4-dihydro[60]fullerene resulting from an efficient nucleophilic substitution has been obtained by reaction of a fullerene epoxide, C60O, with nucleophilic aromatic compounds in the presence of boron trifluoride etherate as a Lewis acid.

Cited by 65 publications

References 27 publications

Cyclobutadiene–C60 Adducts: N‐Type Materials for Organic Photovoltaic Cells with High VOC

Cyclobutadiene–C60 Adducts: N‐Type Materials for Organic Photovoltaic Cells with High VOC

Design Concept for High-LUMO-level Fullerene Electron-acceptors for Organic Solar Cells

Notably Enhanced Reactivity of the Fulleroid anti‐Bredt Double Bond in Diels–Alder Reactions

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About

Cyclobutadiene–C₆₀ Adducts: N‐Type Materials for Organic Photovoltaic Cells with High V_OC

Cyclobutadiene–C₆₀ Adducts: N‐Type Materials for Organic Photovoltaic Cells with High V_OC