Cholesteryl benzoate, also called 5-cholesten-3-yl benzoate, is an

organic chemical In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The ...

, an

ester In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides ...

cholesterol Cholesterol is any of a class of certain organic molecules called lipids. It is a sterol (or modified steroid), a type of lipid. Cholesterol is biosynthesized by all animal cells and is an essential structural component of animal cell membr ...

and

benzoic acid Benzoic acid is a white (or colorless) solid organic compound with the formula , whose structure consists of a benzene ring () with a carboxyl () substituent. It is the simplest aromatic carboxylic acid. The name is derived from gum benzoin, w ...

. It is a

liquid crystal Liquid crystal (LC) is a state of matter whose properties are between those of conventional liquids and those of solid crystals. For example, a liquid crystal may flow like a liquid, but its molecules may be oriented in a crystal-like way. The ...

material forming cholesteric liquid crystals with helical structure. It can be used with cholesteryl nonanoate and cholesteryl oleyl carbonate in some thermochromic liquid crystals. It is used in some hair colors, make-ups, and some other cosmetic preparations. It can be also used as a component of the liquid crystals used for

liquid crystal display A liquid-crystal display (LCD) is a flat-panel display or other electronically modulated optical device that uses the light-modulating properties of liquid crystals combined with polarizers. Liquid crystals do not emit light directly but ...

s. Cholesteryl benzoate was the first material in which liquid crystal properties were discovered. In the late 1880s Friedrich Reinitzer, an

Austria Austria, , bar, Östareich officially the Republic of Austria, is a country in the southern part of Central Europe, lying in the Eastern Alps. It is a federation of nine states, one of which is the capital, Vienna, the most populous ...

n botanist, while studying the chemicals in plants, heated cholesteryl benzoate. At 145 °C the material melted, yielding a cloudy fluid, which changed to the originally expected clear liquid at 178.5 °C. In 1888, the German physicist

Otto Lehmann Otto Lehmann may refer to: * Otto Lehmann (physicist) (1855–1922), German physicist * Otto Lehmann (movie producer) Otto Lehmann (22 January 1889 in Berlin – 28 April 1968 in Munich ) was a German movie producer. Career Lehmann studied to ...

concluded the cloudy fluid presents a new phase of matter, and coined the term ''liquid crystal''.{{cite web, title=History and Properties of Liquid Crystals, url=https://www.nobelprize.org/educational/physics/liquid_crystals/history/, website=Official Web Site of the Nobel Prize, accessdate=5 February 2016

References

Cholestanes Liquid crystals Benzoate esters