Structure and Vibrational Spectrum of Some Polycyclic Aromatic Compounds Studied by Density Functional Theory. 1. Naphthalene, Azulene, Phenanthrene, and Anthracene

Martin, Jan M. L.; El-Yazal, ‡ and Jamal; François, J

doi:10.1021/jp960598q

Cited by 179 publications

(138 citation statements)

References 65 publications

(90 reference statements)

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“…The B3LYP functional has been proved to be a good choice for the description of carbon clusters [25]. In the case of small carbon clusters, the calculated geometries and the vibrational frequencies are very close to those obtained at higher levels of calculations [26][27][28]. More accurate values of electronic and binding energies have been obtained with the coupled cluster theory CCSD(T)/6-311+G(3df), which includes all single and double excitations, as well as triple excitations in a perturbative way [29], and made use of the B3LYP optimized geometry.…”

Section: Computational Detailsmentioning

confidence: 63%

Ionization potentials, dissociation energies and statistical fragmentation of neutral and positively charged small carbon clusters

Díaz‐Tendero¹,

Sánchez‐Sanz²,

Hervieux³

et al. 2006

Braz. J. Phys.

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Dissociation energies, ionization potentials and fragmentation dynamics of neutral, singly-and doubly charged small carbon clusters have been theoretically studied with a combination of the density functional theory, the coupled cluster method and the the statistical model microcanonical Metropolis Monte Carlo. The second ionization potential decreases with the cluster size and is larger than the first one, which also decreases with the size showing oscillations. Dissociation energies also oscillate with the cluster size, being those with an odd number of atoms more stable. C 3 cluster has the largest dissociation energy. The combination of a statistical treatment for the cluster fragmentation with experimental results has allowed us to evaluate the energy distribution in collisions experiments.

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Section: Computational Detailsmentioning

confidence: 63%

Ionization potentials, dissociation energies and statistical fragmentation of neutral and positively charged small carbon clusters

Díaz‐Tendero¹,

Sánchez‐Sanz²,

Hervieux³

et al. 2006

Braz. J. Phys.

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“…There are seven major Raman peaks, which can be conveniently compared between pure and intercalated phenanthrene: 1,524, 1,441, 1,350, 1,037, 830, 411 and 250 cm − 1 , as listed in Table 2. All of these peaks belong to the A 1 mode, and arise mainly from the C-C stretching vibration 26,27 . Compared with the pure phenanthrene, alkali-metaldoped phenanthrene displays obvious downshift, suggesting the phonon-mode softening effect.…”

Section: Resultsmentioning

confidence: 99%

Superconductivity at 5 K in alkali-metal-doped phenanthrene

et al. 2011

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organic superconductors have π-molecular orbitals, from which electrons can become delocalized, giving rise to metallic conductivity due to orbital overlap between adjacent molecules. Here we report the discovery of superconductivity at a transition temperature (T c ) of ~5 K in alkali-metal-doped phenanthrene. A 1-GPa pressure leads to a 20% increase of T c , suggesting that alkali-metal-doped phenanthrene shows unconventional superconductivity. Raman spectra indicate that alkali-metal doping injects charge into the system to realize the superconductivity. The discovery of superconductivity in A 3 phenanthrene (where A can be either K or Rb) produces a novel broad class of superconductors consisting of fused hydrocarbon benzene rings with π-electron networks. An increase of T c with increasing number of benzene rings from three to five suggests that organic hydrocarbons with long chains of benzene rings are potential superconductors with high T c .

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“…The extension of the basis set is less important for DFT than for configuration interaction treatments; more than 15 years of experience have shown that a correct description of the electronic densities is already obtained with atomic expansions of triple zeta quality (see for example Martin et al 1996). It is worth noting that this same B3LYP functional, with equivalent basis set, has been recently used for a study of the photophysics of acetic acid and its isomers (Puletti et al 2010).…”

Section: Computational Backgroundmentioning

confidence: 99%

A new weapon for the interstellar complex organic molecule hunt: the minimum energy principle

Lattelais¹,

Pauzat²,

Ellinger³

et al. 2010

A&A

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Context. The hunt for the interstellar complex organic molecules (COMs) supposed to be the building blocks of the molecules at the origin of life is a challenging but very expensive task. It starts with laboratory experiments, associated with theoretical calculations, that give the line frequencies and strengths of the relevant molecules to be identified and finishes with observations at the telescopes. Aims. The present study aims to suggest possible guidelines to optimize this hunt. Levering on the minimum energy principle (MEP) presented in a previous study, we discuss the link between thermodynamic stability and detectability of a number of structures in the important families of amides, sugars and aminonitriles. Methods. The question of the relative stability of these different species is addressed by means of quantum density functional theory simulations. The hybrid B3LYP formalism was used throughout. All 72 molecules part of this survey were treated on an equal footing. Each structure, fully optimized, was verified to be a stationary point by vibrational analysis. Results. A comprehensive screening of 72 isomers of CH 3 NO, C 2 H 5 NO, C 3 H 7 NO, C 2 H 4 O 2 , C 3 H 6 O 3 and C 2 H 4 N 2 chemical formula has been carried out. We found that formamide, acetamide and propanamide (the first two identified in the Inter-Stellar Medium) are the most stable compounds in their families demonstrating at the same time that the peptide bond >N-C=O at the origin of life is the most stable bond that can be formed. Dihydroxyacetone, whose detection awaits for confirmation, is far from being the most stable isomer of its family while aminoacetonitrile, that has been recently identified, is effectively the most stable species. Conclusions. The MEP appears to be a useful tool for optimizing the hunt for new species by identifying the potentially more abundant isomers of a given chemical formula.

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Structure and Vibrational Spectrum of Some Polycyclic Aromatic Compounds Studied by Density Functional Theory. 1. Naphthalene, Azulene, Phenanthrene, and Anthracene

Cited by 179 publications

References 65 publications

Ionization potentials, dissociation energies and statistical fragmentation of neutral and positively charged small carbon clusters

Ionization potentials, dissociation energies and statistical fragmentation of neutral and positively charged small carbon clusters

Superconductivity at 5 K in alkali-metal-doped phenanthrene

A new weapon for the interstellar complex organic molecule hunt: the minimum energy principle

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