Preferred Label : aromatic;
IUPAC acronym : NMR;
IUPAC definition : the terms aromatic and antiaromatic have been extended to describe the stabilization
or destabilization of transition states of pericyclic reactions the hypothetical reference
structure is here less clearly defined, and use of the term is based on application
of the hückel (4n 2) rule and on consideration of the topology of orbital overlap
in the transition state. reactions of molecules in the ground state involving antiaromatic
transition states proceed, if at all, much less easily than those involving aromatic
transition states.; a cyclically conjugated molecular entity with a stability (due to delocalization )
significantly greater than that of a hypothetical localized structure (e.g. kekulé
structure ) is said to possess aromatic character. if the structure is of higher energy
(less stable) than such a hypothetical classical structure, the molecular entity is
antiaromatic. the most widely used method for determining aromaticity is the observation
of diatropicity in the h1nmr spectrum. hückel (4n 2) rule möbius aromaticity; in the traditional sense, having a chemistry typified by benzene.;
Origin ID : A00441;
UMLS CUI : C0772162;
Automatic exact mappings (from CISMeF team)
- Currated CISMeF NLP mapping
- False automatic mappings
- See also
- Semantic type(s)
- UMLS correspondences (same concept)
the terms aromatic and antiaromatic have been extended to describe the stabilization
or destabilization of transition states of pericyclic reactions the hypothetical reference
structure is here less clearly defined, and use of the term is based on application
of the hückel (4n 2) rule and on consideration of the topology of orbital overlap
in the transition state. reactions of molecules in the ground state involving antiaromatic
transition states proceed, if at all, much less easily than those involving aromatic
transition states.
a cyclically conjugated molecular entity with a stability (due to delocalization )
significantly greater than that of a hypothetical localized structure (e.g. kekulé
structure ) is said to possess aromatic character. if the structure is of higher energy
(less stable) than such a hypothetical classical structure, the molecular entity is
antiaromatic. the most widely used method for determining aromaticity is the observation
of diatropicity in the h1nmr spectrum. hückel (4n 2) rule möbius aromaticity
in the traditional sense, having a chemistry typified by benzene.
