The magnetic circular dichroism and absorption spectra of C60 isolated in Ar matrices

Gasyna, Zbigniew; Schatz, P. N.; Hare, Jonathon; Dennis, T. John S.; Kroto, Harold W.; Taylor, Roger; Walton, D. R. M.

doi:10.1016/0009-2614(91)80064-5

Cited by 133 publications

(78 citation statements)

References 11 publications

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“…At this level of CI approach, Marconi and Salvi [3] have concluded that: "for the lowest permitted states of Ti u symmetry the Α term is well reproduced in size and sign independently from the parametrization and the amount of configuration interaction used". We do not agree with that conclusion as the CNDO/S method used with the limited number of configurations yields the intensities and the magnetic moments of the Τ1u-symmetry states to be strongly at variance with the MCD experiment [4] and also with our later calculations [1]. Moreover, the energies and intensities calculated for the three low-energy T1 u states obtained by Marconi and Salvi [3,5] are also inconsistent with those recently found using the CNDO/S method employed at the same level of CI treatment [6].…”

Section: Introductioncontrasting

confidence: 72%

“…In fact, such a trend is seen in Table. However, the CNDO/S method used with 171 configurations fits the experimental energies [4] at E (lT1u ) = 3.80 eV, Ε(2T1u) = 4.90 eV, Ε(3T1u ) = 5.96 eV, much better than CNDO/S method does with the larger number of 196 configurations. Specifically, the CNDO/S calculations with 196 configurations lead to energies which are significantly lower than those found in the experiment.…”

Section: Resultsmentioning

confidence: 91%

“…The corresponding experimental spectra without the background correction are those reported in Ref. [4].…”

Section: Resultsmentioning

confidence: 99%

“…We wish to note, however, that SCFPPP calculations leading to solid line spectra in Fig. 1b were done without spin-orbit couplings suggested in the original experimental paper [4] to play a role in a interpretation of MCD data. Since the spin-orbit coupling effects are usually small, the minor redistribution of MCD would be expected when 1Τ1u and 3T1u electronic manifolds would be involved in the spin-orbit coupling.…”

Section: Resultsmentioning

confidence: 99%

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Influence of Configuration Interaction on the Magnetic Circular Dichroism Spectra of C₆₀Molecule

Pilch¹,

Pawlikowski²

1993

Acta Phys. Pol. A

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Α1/D0 and D0 characteristics of magnetic circular dichroism and absorption spectra are studied for the low-energy Ag → T1u transitions in the C60 molecule in terms of the self-consistent field Parieser-Parr -Pople method applied in the full configuration interaction -i treatment. The effects are discussed at different levels of configuration interaction and the results are compared to the earlier ones obtained From the CNDO/S method. We argue that the earlier treatment fails to account correctly for the experimental magnetic circular dichroism and absorption spectra of C60 molecule. This is most probably due to deficiency of the configuration interaction basis set and/or to the intrinsic parametrization of complete neglect of differential overlap method.

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Section: Introductioncontrasting

confidence: 72%

Section: Resultsmentioning

confidence: 91%

“…The corresponding experimental spectra without the background correction are those reported in Ref. [4].…”

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Influence of Configuration Interaction on the Magnetic Circular Dichroism Spectra of C₆₀Molecule

Pilch¹,

Pawlikowski²

1993

Acta Phys. Pol. A

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“…This can be extracted from the graph of the integrated strength f E defined in Eq. (29). The jumps at low energies give the f strengths of the discrete transitions.…”

Section: Application To C 60mentioning

confidence: 99%

Magnetic circular dichroism in real-time time-dependent density functional theory

Lee

Yabana

Bertsch

2011

The Journal of Chemical Physics

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We apply the adiabatic time-dependent density functional theory to magnetic circular dichroism (MCD) spectra using the real-space, real-time computational method. The standard formulas for the MCD response and its A and B terms are derived from the observables in the timedependent wave function. We find real time method is well suited for calculating the overall spectrum, particularly at higher excitation energies where individual excited states are numerous and overlapping. The MCD sum rules are derived and intepreted in the real-time formalism; we find that they are very useful for normalization purposes and assessing the accuracy of the theory.The method is applied to MCD spectrum of C 60 using the adiabatic energy functional from the local density approximation. The theory correctly predicts the signs of the A and B terms for the lowest allowed excitations. However, the magnitudes of the terms only show qualitative agreement with experiment.

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Fullerenes

Taylor

2002

Kirk-Othmer Encyclopedia of Chemical Technology

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Fullerenes are closed cage carbon molecules C 2 n ( n ≥ 10) comprising a combination of n carbon atoms of sp 2 (trigonal) hybridisation arranged into 12 pentagons and ( n ‐ 20)/2 hexagons. They are sometimes referred to as the “third form of carbon” (after diamond and graphite). Unlike the other forms of carbon, fullerenes are soluble in many organic solvents and undergo a wide range of standard chemical reactions. They can be formed by various procedures, but most commonly by vaporization of graphite either by use of lasers or electric arc discharge in an inert atmosphere. They do not occur naturally because of their instability arising from fairly rapid air oxidation. For a given value of n , very many isomers (having a wide range of stabilities) are possible, the number increasing geometrically with increasing size of n . Only a few are isolable. The most abundant fullerene is the spherical I h isomer of C 60 (there are 1819 other isomers, all unstable), which has a diameter of ∼10.0 Å. The next most abundant is C 70 , which is shaped like a kiwi fruit, and fullerenes containing >70 atoms are known as higher fullerenes. The geodesic structure of the molecules led to C 60 being named as “Buckminsterfullerene” after R. Buckminsterfullerene who popularized the use of geodesic domes in building construction. This term, now rarely used, gave rise to the abbreviated “fullerenes” for describing the whole class of materials. Because of the curved surfaces of the fullerenes, the π‐electrons are poorly delocalized so that C 60 is not very aromatic and contains essentially 30 double bonds and 60 single bonds. The main chemical reactions of fullerenes are therefore additions, and because of the cage curvature and hybridization state of the carbons, they are strongly electron deficient, reactions with electron‐rich nucleophiles being especially favored. Many derivatives having electron‐donor groups attached to the cage are being investigated with regard to their photoinduced electron‐transfer properties with potential for conversion of light into electricity. The cages are able to enclose a wide variety of atoms and molecules and these incar‐ or endohedral fullerenes have properties that differ from those of the empty cages. Larger fullerenes can also incorporate smaller ones and these multiwall or “nested” fullerenes are known as “onions”. Very elongated cages are known as nanotubes, and are potentially the strongest known constructional materials. These may consist of either a single tube (single‐wall nanotube, SWNT) or numerous concentric tubes within each other (multiwall nanotubes, MWNT), and various elements and molecules have been incorporated inside these also. Aza phospha‐ and borafullerenes have one or more nitrogen, phosphorus, or boron atom, respectively, replacing the corresponding number of carbon atoms in the cage structure. Nanotubes containing both nitrogen and boron atoms are also known. Fullerenes may be joined together in various ways (eg, by the use of high pressure) to give polymeric structures, but these are difficult to process and analyse because of very low solubility. Some fullerenes with alkaline metals incorporated into the lattices show superconducting properties in the solid state, but they are pyrophoric. Although fullerenes are insoluble in water, some derivatives are very soluble and this has led to investigations of biological properties. In particular, their use in connection with removal of free radicals, anti‐ human immunodeficiency virus (HIV) properties, antiviral behavior, and photodynamic therapy are all under investigation.

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The magnetic circular dichroism and absorption spectra of C60 isolated in Ar matrices

Cited by 133 publications

References 11 publications

Influence of Configuration Interaction on the Magnetic Circular Dichroism Spectra of C₆₀Molecule

Influence of Configuration Interaction on the Magnetic Circular Dichroism Spectra of C₆₀Molecule

Magnetic circular dichroism in real-time time-dependent density functional theory

Fullerenes

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The magnetic circular dichroism and absorption spectra of C60 isolated in Ar matrices

Cited by 133 publications

References 11 publications

Influence of Configuration Interaction on the Magnetic Circular Dichroism Spectra of C60Molecule

Influence of Configuration Interaction on the Magnetic Circular Dichroism Spectra of C60Molecule

Magnetic circular dichroism in real-time time-dependent density functional theory

Fullerenes

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Product

Resources

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Influence of Configuration Interaction on the Magnetic Circular Dichroism Spectra of C₆₀Molecule

Influence of Configuration Interaction on the Magnetic Circular Dichroism Spectra of C₆₀Molecule