Although aromaticity has been observed in inorganic and all-metal species, the concept of antiaromaticity has not been extended beyond organic molecules. Here, we present theoretical and experimental evidence that the 6 -electron tetrapnictogen dianions in Na+Pn42- (Pn = P, As, Sb) undergo a transition from being aromatic to antiaromatic upon electron detachment, yielding the first inorganic an...

The physical reason for aromaticity/antiaromaticity was determined. The conclusion was reached after interpreting Hobey's mathematical results that were given in the study of the energy difference between the one-dimensional linear and cyclic particles-in-a-box models. We first revealed that the Huckel theory and particles-in-a-box model are simply different ways of solving the same Schr6dinger...

Isophlorins (two-electron-reduced porphyrins) with 20π antiaromaticity have been synthesized by metallation or core modification (replacing the inner NHs less bulky atoms) thus far. The core-modification number (CMN) is an important factor for stability of isophlorins against their oxidation to porphyrins. However, small CMN (≤ 2), i.e., without significant modification, are difficult synthesiz...

Since its introduction by August Kekulé in 1865,1 the concept of aromaticity has been continuously conquering new territories in chemistry (refs 2-20 are only a small fraction of the published articles, reviews, books, and conference proceedings on this subject). Initially, aromaticity was developed for the following classes of organic compounds: (i) monocyclic planar conjugate hydrocarbons and...

substitution of two or four carbon atoms by nitrogen in the corannulene molecule as a carbon nanostructure was done and the obtained structures were optimized at mp2/6-31g(d) level of theory. calculations of the nucleus-independent chemical shift (nics) were performed to analyze the aromaticity of the corannulene rings and its derivatives upon doping with n at b3lyp/6-31g(d) level of theory. re...

This review focuses on the recent progress in inclusion of a nonbenzenoid ring into π-backbone azaacenes, which can largely tune absorption, energy levels, and antiaromaticity, produce exciting size-dependent properties.