We have studied aromaticity in detail and are acquainted with various compounds that are aromatic. A variety of physical properties have been used as a
130.What is so special about 4n+2 π electrons?
We have been reiterating that aromatic compounds have 4n+2π electrons and antiaromatic compounds 4n π electrons. Ever wondered why these numbers are so important? Let’s
129.Aromaticity(22) -Antiaromaticity.
Aromaticity refers to the extra stability that some cyclic compounds have, owing to their structure. Antiaromaticity means exactly the opposite of that. An aromatic compound
128.Fullerenes.
Elemental carbon in its sp2 hybridized state can form some very interesting structures, which have very wide applications in industry. Fullerenes are one such class
127.Annulenes (2).
Is [12]annulene aromatic? [12]annulene has 4n π electrons and so is anti-aromatic. It is highly unstable compound and exists only at very low temperatures. At
126. Annulenes(1).
Annulenes are completed conjugated monocyclic non-benzenoid hydrocarbons, with a general formula – CnHn ,when n is an even number CnHn+1 , when n is an
125.Polycyclic aromatic hydrocarbons(2)- Azulene,Anthracene, Phenanthrene, Pyrene, Phenacenes.
In the last post we studied naphthalene molecule in detail and we understood why it shows aromatic stability. Similarly , other polycyclic hydrocarbons are also
124.Polycyclic aromatic hydrocarbons(1)- Naphthalene.
In this post we shall discuss aromaticity of some polycyclic aromatic hydrocarbons (PAHs). What are polycyclic aromatic hydrocarbons? Poly = many cyclic = ring structure.
123.Aromaticity(16) – Heterocyclic aromatic systems(2)-Furan,pyrrole and thiophene.
Furan, Pyrrole and Thiophene. All the above structures are similar to each other , except for the fact that pyrrole has a lone pair and
122.Heterocyclic aromatic systems(1)-Pyridine.
In the last post we studied some examples of homocyclic aromatic compounds. What happens if the ring has an atom other than carbon in it?
121.Homocyclic charged aromatic systems.
Benzene with six π electrons – the aromatic sextet– is a “perfect” example of an aromatic compound. In this post we shall study some examples
120 .Cyclobutadiene and benzene.
We learned in detail how HMO theory explains the structure and aromaticity of benzene in previous posts. In this post let us compare benzene to
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