Critique of the notion of aromaticity

Labarre, Jean; Crasnier, François

doi:10.1007/bfb0051963

Cited by 23 publications

(16 citation statements)

References 78 publications

(5 reference statements)

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“…These negative ions are frequently accompanied by a series m/z 89, 181, 273,..., 1101, 1193, which are probably due to solvates of anions of monoaldehydes derived by oxidation. In cases where the sample is insufficiently polar to dissolve in glycerol, we have used tetragol (7) and, where lack of polarity is an even greater problem, teracol (8).…”

Section: Discussionmentioning

confidence: 99%

Fast atom bombardment mass spectrometry: a powerful technique for the study of polar molecules

Williams¹,

Bradley²,

Bojesen³

et al. 1981

J. Am. Chem. Soc.

262

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Section: Discussionmentioning

confidence: 99%

Fast atom bombardment mass spectrometry: a powerful technique for the study of polar molecules

Williams¹,

Bradley²,

Bojesen³

et al. 1981

J. Am. Chem. Soc.

262

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“…This is explained in terms of intense current density induced by a perpendicular magnetic field in the mobile π-electron cloud. Accordingly, the value of Δχ can be related to the degree of electron delocalization, providing a hallmark for the aromatic character of a molecule. , …”

Section: Introductionmentioning

confidence: 99%

Current Density Maps, Magnetizability, and Nuclear Magnetic Shielding Tensors for Anthracene, Phenanthrene, and Triphenylene

et al. 1999

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Ab initio magnetically induced π-electron (first-order) current density maps and second-order magnetic properties, i.e., magnetizabilies, proton, and 13 C magnetic shielding tensors, calculated at coupled Hartree−Fock level of theory by means of the continuous transformation of origin of the current density method (CTOCD), are presented for a series of polycyclic aromatic hydrocarbons. The reliability of the current density maps is documented by the nice agreement between theoretical values for principal values of magnetizabilities and proton magnetic shieldings and corresponding experimental data presently available. For all three of the molecules, the π-electron current flows mainly on the external circuit of carbon atoms. Other intense circulations localized on a single ring take place over the central hexagon of anthracene and, on the contrary, on the external hexagons of phenanthrene and triphenylene. In light of the results obtained in the present work, e.g., taking advantage of high quality current density maps, important details of the ring current model for the molecules under study can be reexamined. Eventually, it is shown that the fundamental information which can be gained from knowledge of the principal components of the magnetic response tensors is easily accessible by means of the CTOCD computational method adopted here.

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“…Several criteria have been proposed to decide if a compound is aromatic or not (Labarre & Crasnier, 1971;Cook, Katritzky & Linda, 1974;Lewis & Peters, 1975). Some of them are based on chemical reactivity and thus refer to excited or transition states; others on physical properties, such as bond lengths and angles, NMR chemical shifts, resonance and stabilization energies, which refer to the ground state.…”

Section: @N ~ (I1mentioning

confidence: 99%