Relative stability of polymerized phases of C60: Depolymerization of a tetragonal phase

Korobov, M.V.; Bogachev, A. G.; Popov, Alexey A.; Senyavin, V. M.; Stukalin, Evgeny B.; Dzyabchenko, A. V.; Davydov, V. A.; Kashevarova, L. S.; Rakhmanina, A. V.; Агафонов, В.

doi:10.1016/j.carbon.2004.11.026

Cited by 26 publications

(11 citation statements)

References 24 publications

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“…In the 2D-T polymer (planar tetragonal polymer, 8 sp 3 -like coordinated carbon atoms), the peak downshifts to 1446 cm −1 , while in the case of the 2D-R phase (planar rhombohedral polymer, 12 sp 3 -like coordinated carbon atoms) the A g (2) mode exhibits the strongest softening and is observed at 1408 cm −1 [9]. The stability of the HPHT C 60 polymers at elevated temperature has been studied by differential scanning calorimetry (DSC) [10][11][12]. Under a heating rate of 10 -20 K/min, DSC measurements show a strong endothermic peak between 525 and 565 K, but no signal was observed during the cooling scan [10].…”

Section: Introductionmentioning

confidence: 99%

“…The change of enthalpy related to the complete polymer decomposition is the highest for the C 60 dimers, decreases for the linear polymeric chains and attains its smallest value for planar polymeric networks. The decomposition kinetics of the planar C 60 polymers was studied by IR absorption and Raman scattering and the formation of intermediate oligomeric states was observed in the case of the rhombohedral polymer [12,13]. Note that in the case of photopolymers, their small amount on the surfaces of bulk samples makes the DSC measurements practically impossible.…”

Section: Introductionmentioning

confidence: 99%

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Comparative Raman study of photo-oligomer stability in the donor-acceptor fullerene complex {Pt(dbdtc)2}•C60 and pristine C60

Meletov¹,

Arvanitidis²,

Christofilos³

et al. 2016

Nanosystems: Phys. Chem. Math.

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The photopolymerization process and the stability of the C 60 photo-oligomers at elevated temperature in the molecular donor-acceptor fullerene complex {Pt(dbdtc) 2 }·C 60 (C 60 complex with platinum dibenzyldithiocarbamate) and pristine fullerite C 60 are studied by Raman spectroscopy. Fast polymerization, manifested by the appearance of additional peaks in the frequency region of the A g (2) pentagon-pinch (PP) mode of the C 60 molecule, was observed upon sample illumination at 514.5 and 532 nm, even at low laser power density as well as at 785 nm at higher power density. The frequencies of the new peaks are in accordance with the empirical dependence of the PP-mode frequency on the number of the sp 3 -like coordinated carbon atoms per molecular cage. The temperature dependence of the polymer content under constant laser power density reveals the decomposition of the photo-oligomers to monomers at ∼ 350 K in the fullerene complex {Pt(dbdtc) 2 }·C 60 and at ∼ 410 K in the case of the pristine C 60 . These values are considerably smaller than the decomposition temperature of 525 -565 K for the crystalline polymers of C 60 .

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Comparative Raman study of photo-oligomer stability in the donor-acceptor fullerene complex {Pt(dbdtc)2}•C60 and pristine C60

Meletov¹,

Arvanitidis²,

Christofilos³

et al. 2016

Nanosystems: Phys. Chem. Math.

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“…We compared the peak positions with previous reported values in various C60 polymer phase as shown in Figure 4 [6][7][8]. The observed IR peak positions correspond with several types of C60 polymers.…”

Section: Resultsmentioning

confidence: 75%

Polymer formation in conductive Mg-doped C<inf>60</inf> films

Kojima

Nishi

Morales

et al. 2011

2011 37th IEEE Photovoltaic Specialists Conference

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Mg-doping in a C60 layer is expected to improve the electrical conduction in organic solar cells. However, the mechanism of conductivity improvement and the detailed structure of Mg-doped C60 material are still unclear. In this study, we investigated the vibrational spectra to understand structural change in Mg-doped C60 in terms of the bonding state of the adjacent C60 molecules. IR spectra can be explained by several types of C60 polymer formation in Mg-doped C60 even with the low Mg concentration. It is thought that the existence of several types of short length C60 polymers cause the crystal quality degradation.

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“…The electron-induced modification of the surface target layer goes through polymerization to fragmentation and amorphization upon the increase of the exposure dose [9,10]. However, fullerene polymers are metastable and undergo spontaneous dissociation to monomer in the temperature range of 400-600 K [18,19,20,21]. Therefore, heating and polymerization/fragmentation of the target material are two interconnected processes in the surface layer of the target whereas in the deeper layers, heat transfer prevails.…”

Section: Resultsmentioning

confidence: 99%

Kinetics of electron-beam dispersion of fullerite C60

Razanau¹,

Mieno²,

Kazachenko³

2012

Nuclear Instruments and Methods in Physics Research Section B:

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Electron-beam dispersion of pressed fullerite C 60 targets in vacuum leads to the deposition of thin films containing polymeric forms of C 60 . The aim of the present report is to analyze physical-chemical processes in the fullerite target during its electronbeam dispersion through the analysis of the kinetics of the radiation temperature of the target surface, the coating growth rate and the density of negative current on the substrate. It was shown that the induction stage of the process is determined by the negative charging and radiation-induced modification and heating of the target. The transitional stage is characterized by nonstationary sublimation of the target material through the pores in the modified surface layer and release of the accumulated negative charge. Stabilization of the process parameters owing to the convection cooling of the target by the sublimation products and the decrease in the pressure inside the microcavities beneath the pores leads to a quasi-stationary stage of target sublimation and deposition of a coating containing polymeric forms of C 60 .

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Relative stability of polymerized phases of C60: Depolymerization of a tetragonal phase

Cited by 26 publications

References 24 publications

Comparative Raman study of photo-oligomer stability in the donor-acceptor fullerene complex {Pt(dbdtc)2}•C60 and pristine C60

Comparative Raman study of photo-oligomer stability in the donor-acceptor fullerene complex {Pt(dbdtc)2}•C60 and pristine C60

Polymer formation in conductive Mg-doped C<inf>60</inf> films

Kinetics of electron-beam dispersion of fullerite C60

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