Benzophenone

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Benzophenone

Benzophenone is the organic compound

Organic compound

An organic compound is any member of a large class of chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of compounds such as carbonates, simple oxides of carbon and cyanides, as well as the allotropes of carbon, are considered Inorganic compound....
with the formula (C

Carbon

Carbon is a chemical element with chemical symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalence?making four electrons available to form covalent bond chemical bonds....
₆H

Hydrogen

Hydrogen is the chemical element with atomic number 1. It is represented by the chemical symbol H. At standard temperature and pressure, hydrogen is a colorless, odorless, nonmetallic, tasteless, highly combustion and explosive Diatomic molecule gas with the molecular formula H2....
₅)₂CO

Oxygen

Oxygen no O2 produced; 2) O2 produced, but absorbed in oceans & seabed rock; 3) O2 starts to gas out of the oceans, but is absorbed by land surfaces and formation of ozone layer; 4-5) O2 sinks filled and the gas accumulates]]...
, generally abbreviated Ph₂CO. Benzophenone is a widely used building block in organic chemistry, being the parent diarylketone.

ophenone can be used as a photo initiator in UV-curing applications such as inks, imaging, and clear coatings in the printing

Printing

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Encyclopedia

Benzophenone is the organic compound

Organic compound

Carbon

Hydrogen

Oxygen

Uses

Benzophenone can be used as a photo initiator in UV-curing applications such as inks, imaging, and clear coatings in the printing

Printing

Printing is a process for reproducing text and image, typically with ink on paper using a printing press. It is often carried out as a large-scale industrial process, and is an essential part of publishing and transaction printing....
industry. Benzophenone prevents ultraviolet (UV) light from damaging scents and colors in products such as perfumes and soaps. It can also be added to the plastic packaging as a UV blocker. Its use allows manufacturers to package the product in clear glass or plastic. Without it, opaque or dark packaging would be required.

Synthesis

Benzophenone can be prepared by the reaction of benzene with carbon tetrachloride

Carbon tetrachloride

Carbon tetrachloride, also known by many other names is the organic compound with the chemical formula CCl4. It is a reagent in organic synthesis chemistry and was formerly widely used in fire extinguishers, as a precursor to refrigerations, and a cleaning agent....
followed by hydrolysis of the resulting diphenyldichloromethane, or by Friedel-Crafts acylation of benzene

Benzene

Benzene, or benzol, is an organic compound chemical compound and a known carcinogen with the molecular formula Carbon6Hydrogen6....
with benzoyl chloride

Benzoyl chloride

Benzoyl chloride, also known as benzenecarbonyl chloride, is a colourless, fuming liquid, C6H5COCl, with an irritating odour....
in the presence of a Lewis acid

Lewis acid

A Lewis acid is a chemical compound, A, that can accept a pair of electrons from a Lewis base, B, that acts as an electron-pair donor, forming an adduct, AB.Gilbert N....
(e.g. aluminium chloride

Aluminium chloride

Aluminium chloride is a chemical compound of aluminium and chlorine. The solid has a low melting and boiling point, and is Covalent bond. It sublimation at 178 ?Celsius....
) catalyst. The industrial synthesis relies on the copper-catalyzed oxidation of diphenylmethane

Diphenylmethane

Diphenylmethane is an organic compound with the chemical formula 2CH2. The compound consists of methane wherein two hydrogen atoms are replaced by two phenyl groups....
with air.

Organic chemistry

Benzophenone is a common photosensitizer

Photosensitizer

In pharmacology, a photosensitizer is a drug, food, or other chemical that increases photosensitivity of the organism. This may be an adverse effect of many drugs, or a desired effect in photodynamic therapy of tumors....
in photochemistry

Photochemistry

Photochemistry, a sub-discipline of chemistry, is the study of the interactions between atoms, small molecules, and light . The pillars of photochemistry are UV/VIS spectroscopy, photochemical reactions in organic chemistry and photosynthesis in biochemistry....
. It crosses

Intersystem crossing

Intersystem crossing is a photophysical process. An isoenergetic non-radiative transition between two electronic states having different Term symbol....
from the S₁ state into the triplet state with nearly 100% yield. The resulting diradical will abstract a hydrogen atom from a suitable hydrogen donor to form a ketyl

Ketyl

A ketyl group in organic chemistry is an anion radical with the general structure C-O. in which an oxygen radical is bonded directly to carbon....
radical

Radical (chemistry)

In chemistry, radicals are atoms, molecules or ions with unpaired electrons on an otherwise open shell configuration. These unpaired electrons are usually highly chemical reaction, so radicals are likely to take part in chemical reactions....
.

Benzophenone radical anion

Sodium reduces benzophenone to the deeply colored radical anion, diphenylketyl:

Na + Ph₂CO ? Na⁺ + Ph₂CO^-

This ketyl is used in the purification of hydrocarbon solvents, because it reacts with water and oxygen to give colorless non-volatile products:

Na + H₂O ? NaOH + 0.5H₂

Commercially significant derivatives

Substituted benzophenones such as oxybenzone

Oxybenzone

Oxybenzone is an organic compound used in sunscreens. It is a derivative of benzophenone. It forms colorless crystals that are readily soluble in most organic solvents....
and dioxybenzone

Dioxybenzone

Dioxybenzone is an organic compound used in sunscreen to block UVB and short-wave UVA rays. It is a derivative of benzophenone. It is a yellow powder with a melting point of 68 ?C....
are used in some sunscreen

Sunscreen

Sunscreen is a lotion, spray, gel or other topical product that absorbs or reflects the sun's ultraviolet radiation and protects the skin.Sunscreens contain one or more UV filters of which there are three main types :...
s. The use of benzophenone-derivatives which structurally resemble a strong photosensitizer

Photosensitizer

Sunscreen controversy

Sunscreen protects against two common forms of skin cancer, squamous cell carcinoma and basal cell carcinoma , and several sunscreen ingredients protect against tumor development in photocarcinogenicity tests in mice....
)

p,p-bis(N,N-dimethylamino)benzophenone or Michler's ketone
Michler's ketone

Michler?s ketone is an organic compound with the formula of [2NC6H4]2CO. This electron-rich derivative of benzophenone is an intermediate in the production of dyes and pigments, for example Methyl violet....
has dimethylamino
Aniline

Aniline, phenylamine or aminobenzene is an organic compound with the Chemical formula C6H7N. It is the simplest and one of the most important aromatic amines, being used as a precursor to more complex chemicals....
substituent
Substituent

In organic chemistry, a substituent is an atom or group of atoms substituted in place of a hydrogen atom on the parent chain of a hydrocarbon. The suffix -yl is used when naming organic compounds that contain a substituent....
s at each para position.

The high-strength polymers PEEK
Peek

The term Peek or PEEK can mean more than one thing, depending on context:* PEEK and POKE, the low-level commands of the BASIC programming language...
, polyetherether ketones, are prepared from derivatives of benzophenone.

See also

Sunscreen
Sunscreen

Sunscreen is a lotion, spray, gel or other topical product that absorbs or reflects the sun's ultraviolet radiation and protects the skin.Sunscreens contain one or more UV filters of which there are three main types :...
for the substituted compounds benzophenone-1 – benzophenone-12

Footnotes

Merck Index, 11th Edition, 1108.

Notations

Gallery
zophenone bottle.jpg|A bottle of benzophenone by Lancaster. Image:Toluene with sodium-benzophenone.jpg|Toluene is refluxed with sodium

Sodium

Sodium is an element which has the symbol Na , atomic number 11, atomic mass 23 amu , and a common oxidation number +1. Sodium is a soft, silvery white, highly reactive element and is a member of the alkali metals within "group 1" ....
and benzophenone to produce dry, oxygen-free toluene. Image:Toluene with sodium-benzophenone - brown.jpg|The mixture is still not blue yet indicating that the reaction is not complete. Image:Toluene with sodium-benzophenone - intense blue.jpg|The intense blue coloration due to the benzophenone ketyl radical shows that the toluene is considered free of air and moisture. Image:Distillation of dry and oxygen-free toluene.jpg|After the toluene has been thoroughly dried by the sodium and benzophenone, it is distilled at atmospheric pressure under a slight positive pressure of nitrogen to prevent contamination by air into the receiving Schlenk flask.