The ascertainment of magnetic aromaticity is not necessarily straightforward, especially for large and bent systems, such as the cycloporphyrin nanorings recently synthesized by group Anderson. Six these were studied here computationally. Indirect methods, based on nuclear shielding magnetizabilities, direct standard quantum mechanics, both used effectively to determine their magnetically induc...

Carbon nanotubes are composed of cylindrical graphite sheets. Both nanotubes and graphite sheets are benzenoid derivatives composed of sp2 carbon atoms arranged in a hexagonal pattern. Therefore both systems are aromatic. The extent of the aromatic character of a molecule G (here benzenoids) can be explained in terms of the number of possible Kekulé structures in G. In this work the Kekulé stru...

Equilibrium geometry, electronic structures, and vibrational modes of CoB8- were investigated in the PBEPBE/6-311+G(d,p) level of theory. The nucleus independent chemical shift (NICS) analysis and magnetizability values were used for studying of aromaticity in CoB8-. The effects of different solvents on the structure and frontier orbital energies were calculated using the polarizable continuum ...

Aromaticity, a very important term in organic chemistry, has never been defined unambiguously. Various ways to describe it come from different phenomena that have experimentally observed. The most examples related some theoretical concepts are presented here.

Several nonradiative processes compete with tryptophan fluorescence emission. The difficulty in spectral interpretation lies in associating specific molecular environmental features with these processes and thereby utilizing the fluorescence spectral data to identify the local environment of tryptophan. Here, spectroscopic and molecular modeling study of Lys-Trp dipeptide charged species shows ...