13C NMR fingerprint characterizes long time-scale structure of Sc3N@C80 endohedral fullerene

Heine, Thomas; Vietze, K.; Seifert, Gotthard

doi:10.1002/mrc.1451

Cited by 55 publications

(49 citation statements)

References 15 publications

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“…Moreover, this type of reasoning should step by step explain the fullerene-encapsulation stability islands (see, e.g., Refs. [12,33]) known throughout the periodic system (though the underlying calculations are quite demanding [34][35][36][37][38][39][40]). The analysis was already applied [41] to the X@C 74 series (X = Mg, Ca, Sr, Ba) where it worked even better owing to a larger uniformity of the Mulliken charge on the metal (very close to 2).…”

Section: Resultsmentioning

confidence: 99%

Computed stabilities in metallofullerene series: Al@C₈₂, Sc@C₈₂, Y@C₈₂, and La@C₈₂

Slanina

Uhlı́k

Lee

et al. 2010

Int J of Quantum Chemistry

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This article reports computations for Al@C 82 , Sc@C 82 , Y@C 82 , and La@C 82 based on encapsulation into the IPR (isolated pentagon rule) C 2v C 82 cage. Their structural and bonding features are also used for evaluations of the relative production yields, employing the encapsulation Gibbs-energy terms and saturated metal pressures. The results can be well related to the ionization potentials of the free metal atoms and thus also rationalized.

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Section: Resultsmentioning

confidence: 99%

Computed stabilities in metallofullerene series: Al@C₈₂, Sc@C₈₂, Y@C₈₂, and La@C₈₂

Slanina

Uhlı́k

Lee

et al. 2010

Int J of Quantum Chemistry

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“…For the C 60 reference, dynamical correction to 13 C nuclear magnetic shielding about À3 to À2 ppm was obtained using different methods comparable with that of À2.5 ppm mentioned previously. 78 If anomalous contribution for atom C e in C 70 is Table 4 Calculated (BHandH/IGLO-III) 13 C chemical shift (in ppm) for C 70 excluded then the ''dynamical'' contribution for C 60 represents approximately 70% of average C 70 values (MD, FPMD). The vibrational (PT2, VCI, TCS) contributions to the 13 C NMR chemical shifts in C 70 are likely to be similar as in C 60 .…”

Section: Chemical Shiftsmentioning

confidence: 99%

Fullerene C70 characterization by 13C NMR and the importance of the solvent and dynamics in spectral simulations

Kaminský

Budêšínský

Taubert

et al. 2013

Phys. Chem. Chem. Phys.

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The nuclear magnetic resonance (NMR) spectroscopy combined with theoretical calculations is an important tool for fullerene identification. However, the accuracy of available theoretical methods is often not adequate. Therefore, in this work, different computational aspects needed to simulate realistically chemical shifts in the C70 molecule are investigated by density functional theory (DFT) calculations. The importance of the functional choice, basis set, solvent, and molecular motions was assessed. The solvent was simulated using the implicit conductor-like polarized continuum model. The molecular motions were included via anharmonic corrections and averaging of snapshots obtained from classical and first-principles molecular dynamics (MD) simulations. Comparison to experiment revealed that density functional calculations typically overestimate the (13)C NMR chemical shifts. Hybrid functionals, such as BHandH and BHandHLYP, and long-range corrected functionals, such as wB97xd and CAM-B3LYP, give the best results. While the solvent has a minor effect (chemical shift changes by ~1 ppm), the vibrational and dynamical effects are surprisingly large, causing changes up to 9 ppm. Consideration of the latter was also necessary to explain the observed temperature dependence. While the dynamical corrections for MD performed in vacuum were overestimated, inclusion of the solvent in simulations provided more realistic results. The study thus points out the importance of an appropriate solvent model and a complex approach to the modelling, balancing the static, dynamic and environmental factors.

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“…Non‐charge‐consistent DFTB was applied to study EMFs, EMCFs, and related compounds on various occasions 29–34, however a benchmark of the method and employed parameter sets with respect to first principles DFT calculations has never before been attempted. In the benchmark study of this paper, we compare molecular and electronic structures as well as energetic data of EMF and EMCF model systems between SCC‐DFTB on one hand, and three different DFT functionals on the other hand.…”

Section: Introductionmentioning

confidence: 99%

Molecular and electronic structures of endohedral fullerenes, Sc₂C₂@C_3v–C₈₂ and Sc₂@C_3v–C₈₂: Benchmark for SCC‐DFTB and proposal of new inner cluster structures

Nishimoto

Wang

Morokuma

et al. 2012

Physica Status Solidi (b)

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The molecular and electronic structures of Sc 2 C 2 @C 3v -C 82 and Sc 2 @C 3v -C 82 were investigated by means of conventional density functional theory (DFT) and the self-consistent-charge density-functional tight-binding (SCC-DFTB, short: ''DFTB'') method. In the DFT calculations, three functionals were adopted: BP86, B3LYP, and PBE. We find that it is necessary to employ tight geometry convergence criteria, which will lead to a reduction of the number of unique isomers. Generally, the DFTB method shows good agreement on relative energies, inner cluster binding energies (BE), and geometries with those predicted by the DFT calculations. In optimized structures, we found that some fullerene cages contain a more linear Sc-CC-Sc inner cluster that are more stable than those containing the butterfly-shaped cluster that was reported before. We found that DFTB overestimates Sc-Sc binding in the case of Sc 2 @C 82 isomers, which became also evident in a comparison of molecular orbital (MO) correlation diagrams between PBE and DFTB methods. It is concluded that DFTB with the present parameters can be reliably employed for fullerene systems consisting of C and Sc atoms without direct Sc-Sc bonding.

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13C NMR fingerprint characterizes long time-scale structure of Sc3N@C80 endohedral fullerene

Cited by 55 publications

References 15 publications

Computed stabilities in metallofullerene series: Al@C₈₂, Sc@C₈₂, Y@C₈₂, and La@C₈₂

Computed stabilities in metallofullerene series: Al@C₈₂, Sc@C₈₂, Y@C₈₂, and La@C₈₂

Fullerene C70 characterization by 13C NMR and the importance of the solvent and dynamics in spectral simulations

Molecular and electronic structures of endohedral fullerenes, Sc₂C₂@C_3v–C₈₂ and Sc₂@C_3v–C₈₂: Benchmark for SCC‐DFTB and proposal of new inner cluster structures

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13C NMR fingerprint characterizes long time-scale structure of Sc3N@C80 endohedral fullerene

Cited by 55 publications

References 15 publications

Computed stabilities in metallofullerene series: Al@C82, Sc@C82, Y@C82, and La@C82

Computed stabilities in metallofullerene series: Al@C82, Sc@C82, Y@C82, and La@C82

Fullerene C70 characterization by 13C NMR and the importance of the solvent and dynamics in spectral simulations

Molecular and electronic structures of endohedral fullerenes, Sc2C2@C3v–C82 and Sc2@C3v–C82: Benchmark for SCC‐DFTB and proposal of new inner cluster structures

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Computed stabilities in metallofullerene series: Al@C₈₂, Sc@C₈₂, Y@C₈₂, and La@C₈₂

Computed stabilities in metallofullerene series: Al@C₈₂, Sc@C₈₂, Y@C₈₂, and La@C₈₂

Molecular and electronic structures of endohedral fullerenes, Sc₂C₂@C_3v–C₈₂ and Sc₂@C_3v–C₈₂: Benchmark for SCC‐DFTB and proposal of new inner cluster structures