An arena is an aromatic hydrocarbon or a hydrocarbon with a single bond or a double bond, and between carbon atoms. Configuration 6 carbon atoms in an aromatic compound called benzene rings. Aromatic hydrocarbons can be monocyclic or polycyclic.
Some aromatic compounds that are not called heteroarena benzene derivatives, these compounds follow Hückel Rule. In these compounds, at least one carbon atom is replaced by another atom, such as oxygen, nitrogen, or sulfur. One contohn compound is furan, a heterocyclic ring compound having 5 members, one oxygen atom. Another example is pyridine, a heterocyclic ring compound with 6 members, one nitrogen atom
Aromatic substitutionIn aromatic substitution,
1 substituents on the ring arena (usually hydrogen) will be replaced with other substituents.
2 main types are electrophilic aromatic substitution (active electrophile reagent) and nucleophilic aromatic substitution (reagennya nucleophile). In the radical-nucleophilic aromatic substitution, a radical form of active reagents. One example is the nitration of salicylic acid: [4]:
Nitration of salicylic acidCouplingsAt couplings, metal will catalyze the coupling between the two radical fragments formal. The results are usually obtained from the coupling reaction is the formation of new carbon-carbon bonds, for example alkilarena, vinyl arena, biraril, the carbon-nitrogen (aniline) or a carbon-oxygen bond new. An example is the arylation of perfluorobenzenaIn the field of organic chemistry, the structure of a series of ring-shaped atoms sometimes have greater stability than expected. Aromaticity is a chemical property in which a conjugated ring bond consists of unsaturated bond, a single pair, or an empty orbit showed stronger stability than the stability of a system consisting only of conjugation. Aromaticity can also be considered a manifestation of cyclic delocalization and resonance.
It is usually thought to occur because the electrons can spin in the form of a circle of atoms, which alternate between single and double covalent bonds. These bonds can be viewed as a hybrid bond (mix) between a single bond and a double bond, all bonds are the same (identical) with the other bond. Models commonly used aromatic ring, a benzene ring (cyclohexatriena) is formed of six-membered carbon ring with alternating, first developed by Kekulé. The model consists of two benzene resonance forms, which describes the single and double bonds covalen an alternate position. Benzene is a more stable molecule than expected regardless of the charge delocalization.
Some aromatic compounds that are not called heteroarena benzene derivatives, these compounds follow Hückel Rule. In these compounds, at least one carbon atom is replaced by another atom, such as oxygen, nitrogen, or sulfur.
BalasHapusmy question is what are the rules Hückel?
Aromatic hydrocarbons can be monocyclic or polycyclic.
what is the difference monocyclic and polycyclic hydrocarbons?
In organic chemistry, Hückel rule determines a planar ring molecules have aromatic properties. This rule was proposed by the German chemist Erich Hückel in 1931.
HapusA planar ring molecules meet Hückel rule, if it has as many as π electron-4N +2, where n is an integer.
From the data aromatics hydrogenation of alkenes are more stable than expected, the stability of the "extra" is caused by a cloud of delocalized electrons, called resonance energy. Criteria for simple aromatic compounds:
Meet Hückel rule, have much 4N π electron cloud +2 in the delocalized p-orbital.
Shaped planar and cyclic.
Each atom in the ring must be able to participate in the delocalization of electrons by having a p-orbital or lone pair.
*Simply put, Huckel's rule for aromaticity states that a monocyclic system will be aromatic if there are 4n + 2 delocalised electrons, (n an integer) contained within it. e.g.: 2, 6, 10, 14 etc
BalasHapus*Polycyclic aromatic compounds are also referred to as aromatics polinuklir, ring-integrated, or compressible ring. Romatik compound is characterized by rings that use certain carbon atoms together and the usual aromatic pi cloud.
Heterocyclic aromatic compound is a compound ring (cyclic) where the atom-atom ring consists of two or more different elements.
Pyridine is an aromatic six-member heterocyclic compounds which is a weak base and has a partial positive ring. pyridine has a structure similar to that of benzene but pyridine terdeaktifkan the electrophilic substitution
Hückel rule determines a planar ring molecules have aromatic properties. This rule was proposed by the German chemist Erich Hückel in 1931.
BalasHapusA planar ring molecules meet Hückel rule, if it has as many as π electron-4N +2, where n is an integer.
From the data aromatics hydrogenation of alkenes are more stable than expected, the stability of the "extra" is caused by a cloud of delocalized electrons, called resonance energy. Criteria for simple aromatic compounds:
Meet Hückel rule, have much 4N π electron cloud +2 in the delocalized p-orbital.
Shaped planar and cyclic.
Each atom in the ring must be able to participate in the delocalization of electrons by having a p-orbital or lone pair.
Polycyclic aromatic compounds are also known as aromatic compounds or ring polinuklir integrated. Aromatic compounds are characterized by aromatic rings that use certain carbon atoms together, or two or more benzene rings combined.
Polycyclic aromatic hydrocarbons and their derivatives largely shaped solids
usually a simple monocyclic aromatic five-membered ring, as pirola, or six-membered rings, such as pyridine.