Phonons and electron-phonon interaction in halogen-fullerene compounds

Лимонов, М. Ф.; Kitaev, Yu. É.; Chugreev, A. V.; Smirnov, V. P.; Grushko, Yu. S.; Kolesnik, S. G.; Koleśnik, S.

doi:10.1103/physrevb.57.7586

Cited by 26 publications

(18 citation statements)

References 15 publications

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“…Because of its high ioni zation potential (7.6 eV), fullerene C 60 is expected not to interact with molecular iodine under no external force. Indeed, some reports indicate the weakness of this inter action [355][356][357]. However, some molecules of about the same ionization potential such as pyrene (7.41 eV) and perlyene (7.00 eV) do act as electrondonors towards molecular iodine [358,359].…”

Section: 234mentioning

confidence: 99%

Molecular iodine/polymer complexes

Moulay

2013

Journal of Polymer Engineering

166

127

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A unique feature of molecular iodine by far, is its ability to bind to polymeric materials. A plethora of natural and synthetic polymers develop complexes when treated with molecular iodine, or with a mixture of mole cular iodine and potassium iodide. Many unexpected findings have been encountered upon complexation of iodine and the polymer skeleton, including the color formation, the polymer morphology changes, the compl exation sites or regions, the biological activity, and the electrical conductivity enhancement of the complexes, with poly iodides (I n¯) , mainly I 3¯ and I 5¯, as the actual binding species. Natural polymers that afford such complexes with iodine species are starch (amylose and amylopectin), chitosan, glycogen, silk, wool, albumin, cellulose, xylan, and natural rubber; iodinestarch being the oldest iodinenatural polymer complex. By contrast, numerous synthetic polymers are prone to make com plexes, including poly(vinyl alcohol) (PVA), poly(vinyl pyrrolidone) (PVP), nylons, poly(Schiff base)s, poly aniline, unsaturated polyhydrocarbons (carbon nano tubes, fullerenes C 60 /C 70 , polyacetylene; iodinePVA being the oldest iodinesynthetic polymer complex.

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Section: 234mentioning

confidence: 99%

Molecular iodine/polymer complexes

Moulay

2013

Journal of Polymer Engineering

166

127

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“…Raman and infrared (IR) spectroscopic techniques [38,39] are useful experimental tools to investigate how doping modifies the structural and dynamical properties of the pristine material and to understand the physical origin of such induced changes. Over the past 10 years, both techniques have been used widely to study the vibrational properties of C 60 [40][41][42][43][44][45], its derivative compounds [46][47][48][49][50][51][52][53][54][55][56][57], and (doped) carbon nanotubes [58][59][60][61][62][63][64]. It has been shown that C 60 has in total 46 vibrational modes including 4 IR-active [40][41][42][43] and 10 Raman-active vibrational modes [44,45].…”

Section: Introductionmentioning

confidence: 99%

First-principles calculations of structural, electronic, vibrational, and magnetic properties of C60 and C48N12: A comparative study

Xie

Bryant

Jensen

et al. 2003

The Journal of Chemical Physics

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We perform first-principles calculations of the structural, electronic, vibrational and magnetic properties of the C48N12 azafullerene and C60. Full geometrical optimization shows that C48N12 is characterized by several distinguishing features: only one nitrogen atom per pentagon, two nitrogen atoms preferentially sitting in one hexagon, S6 symmetry, 6 unique nitrogen-carbon and 9 unique carbon-carbon bond lengths. The Mulliken charge analysis indicates that the doped nitrogen atoms in C48N12 exist as electron acceptors and three-fourths of the carbon atoms as electron donors. Electronic structure calculations of C48N12 show that the highest occupied molecular orbital (HOMO) is a doubly degenerate level of ag symmetry and the lowest unoccupied molecular orbital (LUMO) is a nondegenerate level of au symmetry. The calculated binding energy per atom and HOMO-LUMO energy gap of C48N12 are about 1 eV smaller than those of C60. For both C48N12 and C60, the total energies calculated with STO-3G, 3-21G and 6-31G basis sets differ from the 6-31G* basis set results by about 1.5%, 0.6% and 0.05%, respectively. Because of electron correlations, the HOMO-LUMO gap decreases about 5 eV and the binding energy per atom increases about 2 eV. Our vibrational frequency analysis predicts that C48N12 has in total 116 vibrational modes: 58 modes are infraredactive (29 doubly-degenerate and 29 non-degenerate modes) and 58 modes are Raman-active (29 doubly-degenerate unpolarized and 29 non-degenerate polarized). It is found that C48N12 exhibits eight 13 C and two 15 N NMR (nuclear magnetic resonance) spectral signals. In comparison to isolated carbon or nitrogen atoms, an enhancement in the dipole polarizability is found due to the delocalized π electrons in C48N12 and C60. The average second-order hyperpolarizability of C48N12 is about 55% larger than that of C60. In addition, the effects of basis sets are discussed in detail, and the different methods for calculating nuclear magnetic shielding tensors are compared. Our detailed study of C60 reveals the importance of electron correlations and the choice of basis sets in the first-principles calculations. Our best-calculated results for C60 with the B3LYP hybrid density functional theory are in excellent agreement with experiment and demonstrate the desired efficiency and accuracy needed for obtaining quantitative information on the structural, electronic and vibrational properties of these molecules. Our results suggest that C48N12 has potential applications as semiconductor components, nonlinear optical materials, and possible building blocks for molecular electronics and photonic devices.

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“…6 Though C 60 Cl 24 was proposed to be isostructural to T h -C 60 Br 24 , no redundant proof for the molecular structure of C 60 Cl 24 was actually obtained. Moreover, whenever spectroscopic data for C 60 Cl 24 were presented, 4,7 the presence of broad unresolved bands ruled out the formation of an individual compound, at least with T h molecular symmetry.…”

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confidence: 99%