The degree of -electron (de)localization and aromaticity of a series of polybenzenoid hydrocarbons (PBHs) has been analyzed through the π-contribution to the electron localization function (ELFπ), calculated at the B3LYP/6-311G(d,p) hybrid density functional theory level. The extent of -electron delocalization in the various hexagons of a PBH was determined through analysis of the bifurcation...

In this work, we analyze a series of o-hydroxyaryl aldehydes to discuss the interrelation between the resonance-assisted hydrogen bond (RAHB) formation and the aromaticity of the adjacent aromatic rings. As compared to the nonaromatic reference species (malonaldehyde), the studied compounds can be separated into two groups: first, the set of systems that have a stronger RAHB than that of the re...

Polycyclic aromatic hydrocarbons (PAH) are a prominent substance class with variety of applications in molecular materials science. Their electronic properties crucially depend on the bond topology ways that often highly non-intuitive. Here, we study, using density functional theory, triplet states four biphenylene-derived PAHs finding dramatically different excitation energies for closely rela...

Aquest article analitza i desenvolupa les implicacions tributàries de dos conceptes emergents dels últims mesos: el metavers els NFT. Pel que fa al metavers, s’analitza la tributació quatre negocis digitals es poden donar seu si, com publicitat digital, comerç electrònic, compravenda dades d’usuari d’objectes a través NFT, tot plegat lliga amb concepte jurídic nexe o punt connexió. D’altra band...

Fibonacenes (zig-zag unbranched catacondensed benzenoid hydrocarbons) are a class of polycyclic conjugated systems whose molecular graphs possess remarkable properties, often related with the Fibonacci numbers. This article is a review of the chemical graph theory of fibonacenes, with emphasis on their Kekulé–structure–related and Clar–structure–related properties. ————————————————— ∗Supported ...

Strains of Entamoeba histolytica which were isolated from symptomatic patients and which possess a characteristic pathogenic isoenzyme pattern (zymodeme) have extrachromosomal circular DNA molecules containing RNA genes and clusters of tandemly reiterated PvuI elements. The nucleotide sequence of comparable reiterated BamHI elements present in amebae with nonpathogenic zymodemes differs from th...