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In the current work, the authors analyzed and compared the chemical behavior of some (anti)aromatic compounds. The species selected are benzene and cyclobutadiene as the aromatic and antiaromatic classical examples, respectively. Next, the anion Al42−, which is the first all‐metal molecule catalogued as aromatic and its non‐metallic isoelectronic analog, B42− were also analyzed. The antiaromatic clusters Al44− and B44− were studied in form of lithium salts. And the end, the non‐planar B12 boron cluster and its isoelectronic analogs (B11Be− and B11C+) were considered for being analyzed under the same criterium. The analysis was realized employing the following descriptors: molecular electrostatic potential and local hyper‐softness to get insights concerning local reactivity when facing reagents leading to ionic or covalent interactions. The results show that all the molecules analyzed presented some specific variations in their respective local reactivity despite being labeled as aromatic compounds. This analysis provides a notion that the local reactivity is more based on the nature of the atoms and the molecular geometry than the aromatic character by itself. [ABSTRACT FROM AUTHOR]

In the current work, a new family of isoelectronic analogues to B12 is reported. The construction of this family was performed through the isoelectronic substitution principle to generate species such as B11C+, B11Be−, B10BeC, B10C22+, B10Be22− B9Be2C−, and B9BeC2+. The search for the global minimum was realized by utilizing genetic algorithms, while the induced magnetic field, electronic localization function, magnetic current densities, and multicenter aromaticity criteria were calculated to understand their electronic delocalization. Our results show that, in general, C atoms avoid hypercoordination, whereas we have found species with Be atoms located in hypercoordinated positions that are relatively stable. Our analysis of aromaticity indicates that B12 has double σ and π disk aromaticity. Mono, double or triple substitution of B by C+ or Be− reduces somewhat the aromaticity of the clusters, but less in the case of Be− substitution. [ABSTRACT FROM AUTHOR]

The potential energy surfaces of the [Si.sub.5][Li.sub.n.sup.5-6] (n = 5?7) systems were explored in detail to find feasible way to design three-dimensional star-like silicon structures using the appropriate ligands. The calculation results revealed that the important contribution of ionic character of the Si-Li interactions to induce the formation of a bridged structure and the contribution of reduction of the Pauli repulsion and the maximization of the orbital towards formation of star-like structure.

The [C.sub.5.sup.2-] skeleton in combination with saturated hydrocarbon fragments is used to obtain a series of planar tetracoordinate carbon molecules in cyclic semisaturated hydrocarbons. The system is the first example of semisaturated cycles containing a planar tetracoordinate carbon stabilized only by electronic factors.

The article discusses the designing of different sets of boron rings enclosing the planar hypercoordinate group 14 elements on the basis of the geometrical and electronic fit principles. The set is designed in a way that the boron ring can accommodate the central atom easily.

Inspired by carbo-benzene and its inorganic analogues, in the current work, the viability of extended systems (called carbomers) formed from aromatic small rings was studied. The aluminum aromatic cluster, Al42−, and its isoelectronic carbon analogue, C42+, were employed as starting point. The insertion of alkynyl units into the Al-Al and C-C bonds results in the extended molecules named carbomers. These molecules were compared with the global minima structures, which were searched employing the genetic algorithm program, GEGA. The electronic delocalization (aromaticity) of the isomers was studied with the induced magnetic field (Bind). The results showed that global minimum of C122+ (formed from C42+) was an unexpected diatropic structure which presented a similar magnetic response to the C42+ cluster. Also, optical properties of C122+ were computed. [ABSTRACT FROM AUTHOR]

Abstract: In the present work, we report a simple experimental strategy for the one‐step electrochemical synthesis of nanogranular Cu2O films by copper anodization in fluoride‐containing ethylene glycol media. Microscopic exploration using field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM) and transmission electron microscopy (TEM), shows the formation of spherical shape grains with sizes ranging from 20 to 40 nm. Raman and X‐Ray Photoemission Spectroscopy (XPS) results indicate that only CuI oxide is obtained. A band gap energy Eg=2.01 eV is estimated from UV–vis reflectance spectroscopy indicating that an indirect transition mechanism between semiconductor bands takes place. These evidences indicate that the present synthesis of nanogranular Cu2O films is a promising method for obtaining improved properties of materials for the design of photoelectronic devices. [ABSTRACT FROM AUTHOR]

The stability of the LinBnH2n (n = 3–6) series was analyzed using quantum chemical calculations, and it was found that cyclic isomers are not energetically favored. This is different to what happens in their organic counterparts (CnH2n), where cyclopentane (C5H10) and cyclohexane (C6H12) are the low-lying isomers. Apparently, aromaticity is a key-stabilizing factor that needs to be considered for designing stable lithium-boron hydride analogues of cyclic organic compounds. This is verified in the Li3B3H3+ system, which has been designed as the smallest aromatic carbocation (C3H3+) analogue. The global minimum structure of Li3B3H3+ contains a triangular B3H32− moiety, which has structural and chemical bonding features similar to its organic counterpart. Besides, this new cluster is classified as aromatic according to both the 4n + 2 Hückel rule and the analysis of the induced magnetic field. This theoretical evidence leads us to propose this cluster as a viable target for experimental detection in the gas phase. [ABSTRACT FROM AUTHOR]