High yield selective synthesis of C60 dimers

Tanoue, Koji; Mitani, Tadaoki; Iwasa, Yoshihiro; Izuoka, Akira; Sugawara, Tadashi; Yagi, T.

doi:10.1039/a802382d

Cited by 35 publications

(34 citation statements)

References 8 publications

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“…We focus on the FIR frequency region, 20-650 cm Ϫ1 , which allows us to search for intermolecular modes below 200 cm Ϫ1 and identify features derived from I h C 60 modes in the lower frequency portion of the intramolecular spectrum ͑below 400 cm Ϫ1 ), which has not been measured in previous IR studies of these systems. 3,4,16,17,[22][23][24][25][26]36 Using detailed assignments of on-ball vibrations, we confirm both very narrow and unprecedentedly wide mode splittings which characterize the vibrational spectra of the three different structures.…”

Section: Introductionmentioning

confidence: 57%

“…17 For the orthorhombic polymer, C 60 powder was wrapped in tantalum foil and pressed for 1 h at 1.5 GPa and 300°C inside a lava mold using a piston/cylinder-type press. X-ray diffraction confirmed the same orthorhombic structure as reported in Ref.…”

Section: Methodsmentioning

confidence: 99%

“…13 Methods of preparing the 2 ϩ2 cycloaddition dimer include mechanochemical reaction of C 60 with KCN or Li, 7,14 high-temperature phototransformation, 15 quasihydrostatic compression, 16 and pressurization of the template compound (ET) 2 C 60 . 17 Roomtemperature exposure of C 60 to visible or ultraviolet light creates a disordered array of small closed oligomers, referred to as the photopolymer. 13 The extended 2ϩ2-connected structures ͑1D, 2D, and 3D͒ can be made with neutral C 60 's under a variety of high-pressure high-temperature ͑HPHT͒ conditions.…”

Section: Introductionmentioning

confidence: 99%

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Far-infrared vibrational properties of high-pressure high-temperatureC60polymers and theC60
Long
¹
,
Musfeldt
²
,
Kamarás
³

et al. 2000
Phys. Rev. B
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We report high-resolution far-infrared transmission measurements of the 2ϩ2 cycloaddition C 60 dimer and two-dimensional rhombohedral and one-dimensional orthorhombic high-pressure high-temperature C 60 polymers. In the spectral region investigated (20-650 cm Ϫ1 ), we see no low-energy interball modes, but symmetry breaking of the linked C 60 balls is evident in the complex spectrum of intramolecular modes. Experimental features suggest large splittings or frequency shifts of some I h C 60 -derived modes that are activated by symmetry reduction, implying that the balls are strongly distorted in these structures. We have calculated the vibrations of all three systems by first-principles quantum molecular dynamics and use them to assign the predominant I h C 60 symmetries of observed modes. Our calculations show unprecedentedly large downshifts of T 1u ͑2͒-derived modes and extremely large splittings of other modes, both of which are consistent with the experimental spectra. For the rhombohedral and orthorhombic polymers, the T 1u ͑2͒-derived mode that is polarized along the bonding direction is calculated to downshift below any T 1u ͑1͒-derived modes. We also identify a previously unassigned feature near 610 cm Ϫ1 in all three systems as a widely split or shifted mode derived from various silent I h C 60 vibrations, confirming a strong perturbation model for these linked fullerene structures.

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Section: Introductionmentioning

confidence: 57%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Far-infrared vibrational properties of high-pressure high-temperatureC60polymers and theC60
Long
¹
,
Musfeldt
²
,
Kamarás
³

et al. 2000
Phys. Rev. B
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“…263,264 The splittings and shifts should be useful for detecting possible dimer formation in discrete fullerides. 265 The first fullerenium ion salt to be characterized by infrared spectroscopy was [C 76 + ][CB 11 H 6 Br 6 -]. 30 The D 2 symmetry neutral fullerene has about 20 observable bands, 266 but because of masking absorptions of the anion, the shifts of only seven of these bands can be followed upon oxidation.…”

Section: A Infrared Spectroscopymentioning

confidence: 99%

Discrete Fulleride Anions and Fullerenium Cations

2000

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His research interests include reactive cation and superacid chemistry with inert carborane counterions, ionic liquids, bioinorganic chemistry, spin-coupling phenomena, fullerene chemistry, and new carbon-or porphyrin-based materials. He is a Sloan Fellow, a Dreyfus Teacher−Scholar Awardee, and a Guggenheim Fellow. Robert Bolskar received his B.S. degree in Chemistry from Carroll College in Waukesha, WI, in 1992. He earned his Ph.D. degree at the University of Southern California in Los Angeles under the direction of Christopher Reed in 1997, investigating the synthetic redox chemistry of fullerene anions and cations. In 1998 he moved to the University of California, Riverside, as Managing Research Associate. He is currently Senior Chemist at TDA Research in Wheat Ridge, CO. His research interests include the chemistry and physics of fullerene compounds, supramolecular chemistry, strongly oxidizing systems, and electrophilic cations.

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“…The purified dimer can be unambiguously identified by the IR spectrum. All peaks of its spectrum were assigned as dimer lines by comparing the data with those of dimers prepared by different methods previously [9,10]. Thus, we produced the cycloadduct Ci2o dimer by the above photopolymerization method in spectroscopically pure form.…”

Section: Structure Of the Dimer And The Polymersmentioning

confidence: 99%

Isolation and structure of fullerene photodimer, C[sub 120]

Pekker

2001

AIP Conference Proceedings

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Abstract. Photopolymerization of C 60 was performed on a gram scale via a new monomer transport method. After subsequent extractions of the raw polymer in organic solvents, lOOmg dimer and lOmg mixture of soluble oligomers were yielded. The structures of the soluble fractions and the insoluble polymer were studied by optical spectroscopy and x-ray diffraction methods. According to IR and UV-VIS spectroscopic data, the obtained photodimer is identical to the (2+2) cycloadduct C 12 o prepared previously. In contrast to previous crystallization studies, a fast precipitation of the dimer from toluene gives rise to the formation of a solvent-free microcrystalline solid. The crystal structure of the pure dimer is fee (a= 14.05 A) consisting of closely packed balls with the cycloadduct bonds oriented randomly along the 12 nearest neighbor directions. A linear relationship is found to exist between the fee lattice parameter (a) and the average number of bonded neighbours (n B ) in various photopolymerized structures. For insoluble polymers n B «2 is estimated, supporting previous photopolymer models of small ring or branched clusters.

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High yield selective synthesis of C60 dimers

Cited by 35 publications

References 8 publications

Far-infrared vibrational properties of high-pressure high-temperatureC60polymers and theC60
Long
¹
,
Musfeldt
²
,
Kamarás
³

et al. 2000
Phys. Rev. B
Self Cite
29
2
33
0
View full text Add to dashboard Cite

Far-infrared vibrational properties of high-pressure high-temperatureC60polymers and theC60
Long
¹
,
Musfeldt
²
,
Kamarás
³

et al. 2000
Phys. Rev. B
Self Cite
29
2
33
0
View full text Add to dashboard Cite

Discrete Fulleride Anions and Fullerenium Cations

Isolation and structure of fullerene photodimer, C[sub 120]

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High yield selective synthesis of C60 dimers

Cited by 35 publications

References 8 publications

Far-infrared vibrational properties of high-pressure high-temperatureC60polymers and theC60Long1, Musfeldt2, Kamarás3 et al. 2000Phys. Rev. BSelf Cite292330View full textAdd to dashboardCite

Far-infrared vibrational properties of high-pressure high-temperatureC60polymers and theC60Long1, Musfeldt2, Kamarás3 et al. 2000Phys. Rev. BSelf Cite292330View full textAdd to dashboardCite

Discrete Fulleride Anions and Fullerenium Cations

Isolation and structure of fullerene photodimer, C[sub 120]

Contact Info

Product

Resources

About

Far-infrared vibrational properties of high-pressure high-temperatureC60polymers and theC60
Long
¹
,
Musfeldt
²
,
Kamarás
³

et al. 2000
Phys. Rev. B
Self Cite
29
2
33
0
View full text Add to dashboard Cite

Far-infrared vibrational properties of high-pressure high-temperatureC60polymers and theC60
Long
¹
,
Musfeldt
²
,
Kamarás
³

et al. 2000
Phys. Rev. B
Self Cite
29
2
33
0
View full text Add to dashboard Cite