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Simple aromatic rings are aromatic organic compounds (also known as arenes or aromatics) that consist only of conjugated planar ring systems with delocalized pi electron clouds instead of discrete alternating single and double bonds. Typical simple aromatic compounds are benzene and indole. Image File history File links No higher resolution available. ...
Benzocyclobutene (BCB) is the simplest polycyclic aromatic hydrocarbon, being composed of a benzene ring fused to a cyclobutene ring. ...
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Pentalene has the chemical formula C8H6. ...
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Furan, also known as furane and furfuran, is a heterocyclic organic compound, produced when wood, especially pine-wood, is distilled. ...
Image File history File links Benzofuran_simple_structure. ...
Benzofuran, also known as Cumaron, Coumarone, or benzo[b]furan, is a heterocyclic aromatic organic compound. ...
Image File history File links Isobenzofuran_simple_structure. ...
Image File history File links Pyrrole_simple_structure. ...
Pyrrole, or pyrrol, is a heterocyclic aromatic organic compound, a five-membered ring with the formula C4H5N. Pyrroles are components of larger aromatic rings, including the porphyrins of heme, the chlorins and bacteriochlorins of chlorophyll, and the corrin ring of vitamin B12. ...
Image File history File links Indole_simple_structure. ...
Indole is an aromatic heterocyclic organic compound. ...
Image File history File links Isoindole_simple_structure. ...
Isoindole in heterocyclic chemistry is a benzo fused pyrrole [1]. The compound is an isomer of indole and its reduced form is an isoindoline. ...
Image File history File links Thiophene_simple_structure. ...
Thiophene is an aromatic heterocyclic compound consisting of four carbon atoms and one sulfur atom in a five-membered ring. ...
Image File history File links Benzothiophene_simple_structure. ...
Benzothiophene is an aromatic organic compound with a molecular formula C8H6S and an odor similar to naphthalene (mothballs). ...
Image File history File links Benzo-c-thiophene_simple_structure. ...
Image File history File links Imidazole_simple_structure. ...
Imidazole is a heterocyclic aromatic organic compound. ...
Image File history File links Benzimidazole_simple_structure. ...
Benzimidazole is a heterocyclic aromatic organic compound. ...
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Purine is a heterocyclic aromatic organic compound, consisting of a pyrimidine ring fused to an imidazole ring. ...
Image File history File links Pyrazole_simple_structure. ...
Pyrazole is the simplest pyrazole, a class of organic compounds of the heterocyclic series characterized by a ring structure composed of three carbon atoms and two nitrogen atoms in adjacent positions. ...
Image File history File links Indazole_simple_structure. ...
Indazole is a heterocyclic aromatic organic compound. ...
Image File history File links Oxazole_simple_structure. ...
Oxazole is the parent compound for vast class of heteroaromatic compounds. ...
Image File history File links Benzoxazole_simple_structure. ...
Benzoxazole is an aromatic organic compound with a molecular formula C7H5NO, a benzene-fused oxazole ring structure, and an odor similar to pyridine. ...
Image File history File links Isoxazole_simple_structure. ...
Isoxazole is a heterocyclic aromatic organic compound. ...
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Benzisoxazole is an aromatic organic compound with a molecular formula C7H5NO containing a benzene-fused isoxazole ring structure. ...
Image File history File links Thiazole_simple_structure. ...
Thiazole, or 1,3-thiazole, is a clear to pale yellow flammable liquid and pyridine-like odor with the molecular formula C3H3NS. It is a 5-membered ring, in which two of the vertices of the ring are nitrogen and sulfur, and the other three are carbons [1]. Thiazole is...
Image File history File links Benzothiazole_simple_structure. ...
Benzothiazole is a colorless, slightly viscous liquid with a melting point of 2°C, and a boiling point of 227-228°C. The density of benzothiazole is 1. ...
Image File history File links Benzene_simple_structure. ...
Benzene, also known as benzol, is an organic chemical compound with the formula C6H6. ...
Image File history File links Naphthalene_simple_structure. ...
Naphthalene (not to be confused with naphtha) (also known as naphthalin, naphthaline, tar camphor, white tar, albocarbon, or naphthene), is a crystalline, aromatic, white, solid hydrocarbon, best known as the primary ingredient of mothballs. ...
Image File history File links Anthracene_simple_structure. ...
In chemistry, anthracene is a solid polycyclic aromatic hydrocarbon consisting of three benzene rings derived from coal-tar. ...
Image File history File links Pyridine_simple_structure. ...
Pyridine is a chemical compound with the formula C5H5N. It is a liquid with a distinctively putrid odour. ...
Image File history File links Quinoline_simple_structure. ...
Quinoline, also known as 1-azanaphthalene, 1-benzazine, or benzo[b]pyridine, is a heterocyclic aromatic organic compound. ...
Image File history File links Isoquinoline_simple_structure. ...
Isoquinoline (also benzo[c]pyridine)is a heterocyclic aromatic organic compound. ...
Image File history File links Pyrazine_simple_structure. ...
Pyrazine is a symmetrical molecule. ...
Image File history File links Quinoxaline_simple_structure. ...
Quinoxalines, also called benzopyrazines, in organic chemistry, are heterocyclic compounds containing a ring complex made up of a benzene ring and a pyrazine ring (formula I); they are isomeric with the cinnolenes, phthalazines and quinazolines. ...
Image File history File links Acridine_simple_structure. ...
Acridine, C13H9N, is an organic compound and a nitrogen heterocycle. ...
Image File history File links Pyrimidine_simple_structure. ...
Pyrimidine is a heterocyclic aromatic organic compound similar to benzene and pyridine, containing two nitrogen atoms at positions 1 and 3 of the six-member ring [1]. It is isomeric with two other forms of diazine. ...
Image File history File links Quinazoline_simple_structure. ...
Quinazoline is a compound made up of two fused six-membered simple aromatic rings. ...
Image File history File links Pyridazine_simple_structure. ...
Pyridazine is a heteroaromatic organic compound with the molecular formula C4H4N2. ...
Image File history File links Cinnoline_simple_structure. ...
Portions of this article or section may be outdated. ...
In chemistry, an aromatic molecule is one in which electrons are free to cycle around circular arrangements of atoms, which are alternately singly and doubly bonded to one another. ...
Benzene is the simplest of the arenes, a family of organic compounds An organic compound is any member of a large class of chemical compounds whose molecules contain carbon and hydrogen; therefore, carbides, carbonates, carbon oxides and elementary carbon are not organic (see below for more on the definition controversy...
A chemically conjugated system, is a system of atoms covalently bonded with alternating single and double bonds (e. ...
In chemistry, delocalized electrons are electrons in a molecule that do not belong to a single atom or a covalent bond. ...
Geometry of the water molecule Molecules have fixed equilibrium geometries--bond lengths and angles--that are dictated by the laws of quantum mechanics. ...
Covalently bonded hydrogen and carbon in a molecule of methane. ...
Covalent bonding is a form of chemical bonding characterized by the sharing of one or more pairs of electrons between atoms, in order to produce a mutual attraction, which holds the resultant molecule together. ...
Benzene, also known as benzol, is an organic chemical compound with the formula C6H6. ...
Indole is an aromatic heterocyclic organic compound. ...
Simple aromatic rings can be heterocyclic if they contain non-carbon ring atoms, e.g. oxygen, nitrogen, or sulfur. Heterocyclic compounds are substances which contain a ring structure as found in benzene and the aromatic compounds, or aromatic hydrocarbons, but in which other atoms than carbon, such as sulfur, oxygen or nitrogen are found as part of the ring. ...
General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Standard atomic weight 12. ...
General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Standard atomic weight 15. ...
General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless gas Standard atomic weight 14. ...
General Name, Symbol, Number sulfur, S, 16 Chemical series nonmetals Group, Period, Block 16, 3, p Appearance lemon yellow Standard atomic weight 32. ...
Simple monocyclic aromatic rings are usually five-membered rings like pyrrole or six-membered rings like pyridine. Fused aromatic rings like naphthalene or purine consist of monocyclic rings that share their connecting bonds. Pyrrole, or pyrrol, is a heterocyclic aromatic organic compound, a five-membered ring with the formula C4H5N. Pyrroles are components of larger aromatic rings, including the porphyrins of heme, the chlorins and bacteriochlorins of chlorophyll, and the corrin ring of vitamin B12. ...
Pyridine is a chemical compound with the formula C5H5N. It is a liquid with a distinctively putrid odour. ...
Naphthalene (not to be confused with naphtha) (also known as naphthalin, naphthaline, tar camphor, white tar, albocarbon, or naphthene), is a crystalline, aromatic, white, solid hydrocarbon, best known as the primary ingredient of mothballs. ...
Purine is a heterocyclic aromatic organic compound, consisting of a pyrimidine ring fused to an imidazole ring. ...
The nitrogen (N) containing aromatic rings can be separated into non-basic and basic aromatic rings: Acids and bases: Acid-base reaction pH Self-ionization of water Buffer solutions Systematic naming Acid-base extraction Acidity function Proton affinity Acids: Strong acids Weak acids Superacids Lewis acids Mineral acids Organic acids Bases: Strong bases Weak bases Superbases Lewis bases Organic bases edit In chemistry, a base is...
Basic aromatic rings are aromatic rings in which the lone pair of electrons of a ring_nitrogen atom is not part of the aromatic system and extends in the plane of the ring. ...
- In the non-basic rings the lone pair of electrons of the nitrogen atom is delocalized and contributes to the aromatic pi electron system. In these compounds the nitrogen atom is connected to a hydrogen atom. Examples of non-basic nitrogen-containing aromatic rings are pyrrole and indole.
- In the basic aromatic rings the lone pair of electrons is not part of the aromatic system and extends in the plane of the ring. This lone pair is responsible for the basicity of these nitrogenous bases, similar to the nitrogen atom in amines. In these compounds the nitrogen atom is not connected to a hydrogen atom. Examples of basic aromatic rings are pyridine or quinoline. Several rings contain basic as well as non-basic nitrogen atoms, e.g. imidazole and purine. Under acidic conditions these compounds get protonated and form aromatic cations (e.g. pyridinium).
In the oxygen (O) and sulfur (S) containing aromatic rings one of the electron pairs of the heteroatoms contributes to the aromatic system (similar to the non-basic nitrogen containing rings), while the second lone pair extends in the plane of the ring (similar to the basic nitrogen containing rings). A lone pair is an electron pair without bonding or sharing with other atoms. ...
e- redirects here. ...
Nitrogenous bases are organic compounds that owe their basic properties to the lone pair of electrons of a nitrogen atom. ...
The general structure of an amine Amines are organic compounds and a type of functional group that contain nitrogen as the key atom. ...
Acidity redirects here. ...
Protonation is the addition of a proton (H+) to an atom, molecule, or ion. ...
A cation is an ion with positive charge. ...
Pyridinium cation Pyridinium refers to the cationic form of pyridine. ...
Criteria for Aromaticity - Molecule must be cyclic.
- Every atom in the ring must have a "p" orbital which overlaps with "p" orbitals on either side (completely conjugated).
- Molecule must be planar.
- It must contain an odd number of pairs of pi electrons; must satisfy Huckel's rule: (4n+1) pi electrons, where n is an integer starting at zero.
In contrast, molecules with 4n pi electrons are antiaromatic.
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