Tetraphenylcyclopentadienone
Encyclopedia
Tetraphenylcyclopentadienone is a dark purple to black crystalline solid at standard temperature and pressure. Because of its highly conjugated nature, this organic compound
can be analyzed in the UV spectrum. Tetraphenylcyclopentadienone has a "propeller" shape in its 3D conformation
. The four phenyl rings are rotated out of the plane compared to the central ring because of steric repulsion with each other. These rings reduce the reactivity of the cyclopentadienone core by sterically blocking other reactants from getting close enough to it.
between benzil
and dibenzyl ketone
(1,3-diphenyl-2-propanone) using various bases as catalysts.
in the Diels-Alder synthesis of 1,2,3,4-tetraphenylnaphthalene
with benzyne as the dienophile. It may also be used to prepare hexaphenylbenzene
by reaction with diphenylacetylene
in the Diels-Alder reaction
. Similarly, pentaphenylpyridine derivatives may be prepared via a Diels-Alder reaction between tetraphenylcyclopentadienone and benzonitrile
.
Organic compound
An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...
can be analyzed in the UV spectrum. Tetraphenylcyclopentadienone has a "propeller" shape in its 3D conformation
Chemical structure
A chemical structure includes molecular geometry, electronic structure and crystal structure of molecules. Molecular geometry refers to the spatial arrangement of atoms in a molecule and the chemical bonds that hold the atoms together. Molecular geometry can range from the very simple, such as...
. The four phenyl rings are rotated out of the plane compared to the central ring because of steric repulsion with each other. These rings reduce the reactivity of the cyclopentadienone core by sterically blocking other reactants from getting close enough to it.
Synthesis
It can be made by a double Aldol condensationAldol condensation
An aldol condensation is an organic reaction in which an enol or an enolate ion reacts with a carbonyl compound to form a β-hydroxyaldehyde or β-hydroxyketone, followed by a dehydration to give a conjugated enone....
between benzil
Benzil
Benzil is the organic compound with the formula 2, generally abbreviated 2. This yellow solid is one of the most common diketones...
and dibenzyl ketone
Dibenzyl ketone
Dibenzyl ketone, or 1,3-diphenylacetone, is an organic compound composed of two benzyl groups attached to a central carbonyl group. This results in the central carbonyl carbon atom being electrophilic and the two adjacent carbon atoms slightly nucleophilic...
(1,3-diphenyl-2-propanone) using various bases as catalysts.
Reactions
Tetraphenylcyclopentadienone is used as the dieneDiene
In organic chemistry a diene or diolefin is a hydrocarbon that contains two carbon double bonds.Conjugated dienes are functional groups, with a general formula of CnH2n-2. Dienes and alkynes are functional isomers...
in the Diels-Alder synthesis of 1,2,3,4-tetraphenylnaphthalene
1,2,3,4-Tetraphenylnaphthalene
1,2,3,4-Tetraphenylnaphthalene is a polycyclic aromatic hydrocarbon commonly prepared in the undergraduate teaching laboratory as an introduction to the Diels-Alder reaction, in this case between benzyne and tetraphenylcyclopentadienone . It has two crystalline forms, and therefore has two...
with benzyne as the dienophile. It may also be used to prepare hexaphenylbenzene
Hexaphenylbenzene
Hexaphenylbenzene is an aromatic compound composed of a benzene ring substituted with six phenyl rings.It may be prepared through a Diels-Alder reaction by refluxing tetraphenylcyclopentadienone and diphenylacetylene in benzophenone or other high-temperature solvent.-Structure:Due to steric...
by reaction with diphenylacetylene
Diphenylacetylene
Diphenylacetylene is the chemical compound C6H5C≡CC6H5. The molecule consists of phenyl groups attached to both ends of an alkyne. It is a colorless crystalline material that is widely used as a building block in organic and as a ligand in organometallic chemistry.-Preparation:Several...
in the Diels-Alder reaction
Diels-Alder reaction
The Diels–Alder reaction is an organic chemical reaction between a conjugated diene and a substituted alkene, commonly termed the dienophile, to form a substituted cyclohexene system. The reaction can proceed even if some of the atoms in the newly formed ring are not carbon...
. Similarly, pentaphenylpyridine derivatives may be prepared via a Diels-Alder reaction between tetraphenylcyclopentadienone and benzonitrile
Benzonitrile
Benzonitrile is the chemical compound with the formula C6H5CN, abbreviated PhCN. This aromatic organic compound is colourless, with a sweet almond odour. It is prepared by the dehydration of benzamide, or by the reaction of sodium cyanide with bromobenzene....
.