Annulene - Wikipedia
WEBAromaticity. Annulenes may be aromatic (benzene, [6]annulene and [18]annulene), non-aromatic ( [8] and [10]annulene), or anti-aromatic (cyclobutadiene, [4]annulene). Cyclobutadiene is the only annulene with considerable antiaromaticity, since …
Cyclodecapentaene - Wikipedia
WEBCyclodecapentaene or [10]annulene is an annulene with molecular formula C 10 H 10. This organic compound is a conjugated 10 pi electron cyclic system and according to Huckel's rule it should display aromaticity. It is not aromatic, however, because various types of ring strain destabilize an all-planar geometry. [1]: 121–122
The anti-aromatic dianion and aromatic tetraanion of [18]annulene …
WEBMar 6, 2024 · Molecules with circuits of 4 n + 2 π electrons, such as [18]annulene (n = 4), are aromatic, with enhanced stability and diatropic ring currents (magnetic shielding inside the ring), whereas...
Rules for Aromaticity: The 4 Key Factors - Master Organic …
WEBFeb 23, 2017 · So what are the rules? How can we predict whether a molecule is aromatic or not? Table of Contents. Four Key Rules for Aromaticity. Condition #1 for Aromaticity: The Molecule Must Be Cyclic. Condition #2: Every atom in the ring must be conjugated. Condition #3: The Molecule Must Have [4n+2] Pi Electrons. Which Electrons Count As “Pi …
Cyclooctadecanonaene - Wikipedia
WEBAromaticity. Notably, [18]annulene is the first annulene after benzene ( [6]annulene) to be fully aromatic: its π-system contains 4n + 2 electrons (n = 4), and it is large enough to comfortably accommodate six hydrogen atoms in its interior, allowing it to adopt a planar shape, thus satisfying Hückel's rule.
Annulenes - Chemistry Steps
WEBAntiaromatic to Aromatic Conversion. Like [12]annulene, [16]annulene has also 4n electrons and it has been found to be antiaromatic. Interestingly, it can be converted into an aromatic dianion (18 electrons) or a dictation (14 electrons) :
Aromaticity of annulenes - Chemistry Stack Exchange
WEBJan 23, 2018 · [18]Annulene possesses several properties that qualify it as aromatic. However, none of the larger annulenes are as stable as benzene, as their reactivity more closely resembles a conjugated polyene than an aromatic hydrocarbon.
Aromaticity: The Alternating C - Wiley Online Library
WEBAug 9, 2004 · However, this widely accepted structure of [18]annulene is not correct. The 1 H NMR chemical shifts and energy computations show that [18]annulene prefers C C bond-length alternation and C2 symmetry.
Synthesis of a highly aromatic and planar dehydro [10]annulene …
WEBAug 15, 2022 · The first reported alternant aromatic [10]annulene derivative is the bridged 1,6-methano [10]annulene (4). It was prepared by Vogel in 1964 (ref. 32) and has recently shown potential as an...
Möbius aromaticity and antiaromaticity in expanded porphyrins
WEBThis leads to the conclusion that the annulenes containing [4 n] π -electron peripheries will be 'Möbius aromatic', whereas those with [4 n + 2] π electrons will be 'Möbius antiaromatic ...