منابع مشابه
Double aromaticity in monocyclic carbon, boron, and borocarbon rings based on magnetic criteria.
The double-aromatic character of selected monocyclic carbon, boron, and borocarbon rings is demonstrated by refined nucleus-independent chemical shift (NICS) analyses involving the contributions of individual canonical MOs and their out-of-plane NICS tensor component (CMO-NICS(zz)). The double aromaticity considered results from two mutually orthogonal Hückel p AO frameworks in a single molecul...
متن کاملAromaticity of the planar hetero[8]circulenes and their doubly charged ions: NICS and GIMIC characterization.
A series of planar hetero[8]circulenes and their doubly charged ions are studied by the NICS and GIMIC methods to interpret the aromatic properties of these high symmetry species. In accordance with the performed calculations all studied hetero[8]circulenes are found to be nonaromatic compounds because paratropic and diatropic ring-currents are completely canceled yielding almost zero net curre...
متن کاملShannon entropy as a new measure of aromaticity, Shannon aromaticity.
Based on the local Shannon entropy concept in information theory, a new measure of aromaticity is introduced. This index, which describes the probability of electronic charge distribution between atoms in a given ring, is called Shannon aromaticity (SA). Using B3LYP method and different basis sets (6-31G**, 6-31+G** and 6-311++G**), the SA values of some five-membered heterocycles, C(4)H(4)X, a...
متن کاملAromaticity Alexandru
Aromaticity has been lately in the center of attention of chemists with books [1-3], journal special issues [4-10], reviews [11, 12], and publications (these are too numerous to cite). The discoveries of fullerenes, nanotubes, nanocones, and nanotori as well as the recent techniques for obtaining graphene sheets with monatomic thickness and astounding properties have enlarged our views about th...
متن کاملAromaticity of Carbon Nanotubes
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...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Bulletin of the Chemical Society of Japan
سال: 1976
ISSN: 0009-2673,1348-0634
DOI: 10.1246/bcsj.49.1427