Richard August Carl Emil Erlenmeyer
Encyclopedia
Richard August Carl Emil Erlenmeyer or Emil Erlenmeyer (28 June 1825 – 22 January 1909) was a German chemist
known for formulating the Erlenmeyer Rule
and designing a type of chemical flask
.
to study medicine, but after attending lectures of Justus von Liebig
changed to chemistry. In the summer of 1846 he went to Heidelberg
for one year, and studied physics, botany and mineralogy returning to Giessen in 1847. After serving as assistant to H. Will and then to Carl Remigius Fresenius
, Erlenmeyer decided to devote himself to pharmaceutical chemistry. For this purposes he studied in Nassau, where he passed the State pharmaceutical examination, and shortly afterwards acquired an apothecary’s business, first at Katzenelnbogen
and then in Wiesbaden
. He soon dissatisfied in pharmacy and returned to chemistry, graduating in Giessen in 1850. In 1855 he moved to Heidelberg and there converted a shed into a private laboratory. In 1857 he became privatdocent and his PhD thesis "On the manufacture of the artificial manure known as superphosphate” contained a description of several crystalline substances which greatly interested Robert Bunsen
. It was while at Heidelberg that Erlenmeyer was brought under the influence of Friedrich Kekulé
, whose theoretical views he was one of the first to adopt. In 1863, he became "extraordinary professor" at the University of Heidelberg and in 1868 was called to Munich
to take charge of the laboratories of the new Polytechnic School, a post which he held until his retirement from teaching in 1883. His work mostly focused on theoretical chemistry, where he suggested the formula for naphthalene
and formulated the Erlenmeyer Rule: alcohol
s in which the hydroxyl group is attached directly to a double-bonded carbon
atom become aldehyde
s or ketone
s. Erlenmeyer’s practical investigations were concerned mostly with aliphatic compound
s. In 1859 he synthesised aminohexoic acid and proceeded to study the general behavior of albumin
oids on hydrolysis
. He worked out methods to determine the relative amounts of leucine
and tyrosine
, which are produced during the degradation of several substances of this class, and was the first (1860) to understand the nature of glycide and to suggest that this substance is related to glycerol
in the same way as is metaphosphoric acid to orthophosphoric acid. In the following year he studied the action of hydriodic acid on glycerol
, and showed that the product is isopropyl
- and not propyl iodide
. His investigations of the higher alcohols produced during fermentation yielded the important proof that these alcohols do not belong to the normal series.
His other work included the isolation of glycolic acid
from unripe grapes (1864), synthesis of sodium oxalate by heating sodium formate
(1868), hydrolysis of ether to alcohol (1858), synthesis of phenyl-lactic acid (1880), preparation of pyruvic acid
by the distillation of tartaric acid
(1881) and the formation of carbostyril from quinoline
(1885). His investigations in the aromatic series include isomerism of the cinnamic acid
s and the synthesis of tyrosine
from phenylalanine
(1882). In 1875, by nitrating benzoic acid
, Erlenmeyer disproved the prevalent opinion that more than three nitrobenzoic acid
s exist. In 1861 he invented the conical flask
that bears his name.
Chemist
A chemist is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties such as density and acidity. Chemists carefully describe the properties they study in terms of quantities, with detail on the level of molecules and their component atoms...
known for formulating the Erlenmeyer Rule
and designing a type of chemical flask
Erlenmeyer flask
An Erlenmeyer flask, also known as a conical flask, is a widely used type of laboratory flask which features a flat bottom, a conical body, and a cylindrical neck. It is named after the German chemist Emil Erlenmeyer, who created it in 1861...
.
Biography
Erlenmeyer was the son of Dr. Friedrich Erlenmeyer, a Protestant theologist. He enrolled to the University of GiessenUniversity of Giessen
The University of Giessen is officially called the Justus Liebig University Giessen after its most famous faculty member, Justus von Liebig, the founder of modern agricultural chemistry and inventor of artificial fertiliser.-History:The University of Gießen is among the oldest institutions of...
to study medicine, but after attending lectures of Justus von Liebig
Justus von Liebig
Justus von Liebig was a German chemist who made major contributions to agricultural and biological chemistry, and worked on the organization of organic chemistry. As a professor, he devised the modern laboratory-oriented teaching method, and for such innovations, he is regarded as one of the...
changed to chemistry. In the summer of 1846 he went to Heidelberg
Heidelberg
-Early history:Between 600,000 and 200,000 years ago, "Heidelberg Man" died at nearby Mauer. His jaw bone was discovered in 1907; with scientific dating, his remains were determined to be the earliest evidence of human life in Europe. In the 5th century BC, a Celtic fortress of refuge and place of...
for one year, and studied physics, botany and mineralogy returning to Giessen in 1847. After serving as assistant to H. Will and then to Carl Remigius Fresenius
Carl Remigius Fresenius
Carl Remigius Fresenius , was a German chemist, known for his studies in analytical chemistry.- Biography :Fresenius was born on 28 December 1818, in Frankfurt, Germany...
, Erlenmeyer decided to devote himself to pharmaceutical chemistry. For this purposes he studied in Nassau, where he passed the State pharmaceutical examination, and shortly afterwards acquired an apothecary’s business, first at Katzenelnbogen
Katzenelnbogen
Katzenelnbogen is the name of a castle and small city in the district of Rhein-Lahn-Kreis in Rhineland-Palatinate, Germany. Katzenelnbogen is the seat of the Verbandsgemeinde Katzenelnbogen.-History:...
and then in Wiesbaden
Wiesbaden
Wiesbaden is a city in southwest Germany and the capital of the federal state of Hesse. It has about 275,400 inhabitants, plus approximately 10,000 United States citizens...
. He soon dissatisfied in pharmacy and returned to chemistry, graduating in Giessen in 1850. In 1855 he moved to Heidelberg and there converted a shed into a private laboratory. In 1857 he became privatdocent and his PhD thesis "On the manufacture of the artificial manure known as superphosphate” contained a description of several crystalline substances which greatly interested Robert Bunsen
Robert Bunsen
Robert Wilhelm Eberhard Bunsen was a German chemist. He investigated emission spectra of heated elements, and discovered caesium and rubidium with Gustav Kirchhoff. Bunsen developed several gas-analytical methods, was a pioneer in photochemistry, and did early work in the field of organoarsenic...
. It was while at Heidelberg that Erlenmeyer was brought under the influence of Friedrich Kekulé
Friedrich August Kekulé von Stradonitz
Friedrich August Kekule von Stradonitz was a German organic chemist. From the 1850s until his death, Kekule was one of the most prominent chemists in Europe, especially in theoretical chemistry...
, whose theoretical views he was one of the first to adopt. In 1863, he became "extraordinary professor" at the University of Heidelberg and in 1868 was called to Munich
Munich
Munich The city's motto is "" . Before 2006, it was "Weltstadt mit Herz" . Its native name, , is derived from the Old High German Munichen, meaning "by the monks' place". The city's name derives from the monks of the Benedictine order who founded the city; hence the monk depicted on the city's coat...
to take charge of the laboratories of the new Polytechnic School, a post which he held until his retirement from teaching in 1883. His work mostly focused on theoretical chemistry, where he suggested the formula for naphthalene
Naphthalene
Naphthalene is an organic compound with formula . It is a white crystalline solid with a characteristic odor that is detectable at concentrations as low as 0.08 ppm by mass. As an aromatic hydrocarbon, naphthalene's structure consists of a fused pair of benzene rings...
and formulated the Erlenmeyer Rule: alcohol
Alcohol
In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....
s in which the hydroxyl group is attached directly to a double-bonded carbon
Carbon
Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...
atom become aldehyde
Aldehyde
An aldehyde is an organic compound containing a formyl group. This functional group, with the structure R-CHO, consists of a carbonyl center bonded to hydrogen and an R group....
s or ketone
Ketone
In organic chemistry, a ketone is an organic compound with the structure RCR', where R and R' can be a variety of atoms and groups of atoms. It features a carbonyl group bonded to two other carbon atoms. Many ketones are known and many are of great importance in industry and in biology...
s. Erlenmeyer’s practical investigations were concerned mostly with aliphatic compound
Aliphatic compound
In organic chemistry, aliphatic compounds are acyclic or cyclic, non-aromatic carbon compounds.Thus, aliphatic compounds are opposite to aromatic compounds.- Structure :...
s. In 1859 he synthesised aminohexoic acid and proceeded to study the general behavior of albumin
Albumin
Albumin refers generally to any protein that is water soluble, which is moderately soluble in concentrated salt solutions, and experiences heat denaturation. They are commonly found in blood plasma, and are unique to other blood proteins in that they are not glycosylated...
oids on hydrolysis
Hydrolysis
Hydrolysis is a chemical reaction during which molecules of water are split into hydrogen cations and hydroxide anions in the process of a chemical mechanism. It is the type of reaction that is used to break down certain polymers, especially those made by condensation polymerization...
. He worked out methods to determine the relative amounts of leucine
Leucine
Leucine is a branched-chain α-amino acid with the chemical formula HO2CCHCH2CH2. Leucine is classified as a hydrophobic amino acid due to its aliphatic isobutyl side chain. It is encoded by six codons and is a major component of the subunits in ferritin, astacin and other 'buffer' proteins...
and tyrosine
Tyrosine
Tyrosine or 4-hydroxyphenylalanine, is one of the 22 amino acids that are used by cells to synthesize proteins. Its codons are UAC and UAU. It is a non-essential amino acid with a polar side group...
, which are produced during the degradation of several substances of this class, and was the first (1860) to understand the nature of glycide and to suggest that this substance is related to glycerol
Glycerol
Glycerol is a simple polyol compound. It is a colorless, odorless, viscous liquid that is widely used in pharmaceutical formulations. Glycerol has three hydroxyl groups that are responsible for its solubility in water and its hygroscopic nature. The glycerol backbone is central to all lipids...
in the same way as is metaphosphoric acid to orthophosphoric acid. In the following year he studied the action of hydriodic acid on glycerol
Glycerol
Glycerol is a simple polyol compound. It is a colorless, odorless, viscous liquid that is widely used in pharmaceutical formulations. Glycerol has three hydroxyl groups that are responsible for its solubility in water and its hygroscopic nature. The glycerol backbone is central to all lipids...
, and showed that the product is isopropyl
Isopropyl
In organic chemistry, isopropyl is a propyl with a group attached to the secondary carbon. If viewed as a functional group an isopropyl is an organic compound with a propyl group attached at its secondary carbon.The bond is therefore on the middle carbon....
- and not propyl iodide
Propyl iodide
Propyl iodide may refer to:* n-Propyl iodide* Isopropyl iodide...
. His investigations of the higher alcohols produced during fermentation yielded the important proof that these alcohols do not belong to the normal series.
Glycolic acid
Glycolic acid is the smallest α-hydroxy acid . This colorless, odorless, and hygroscopic crystalline solid is highly soluble in water. It is used in various skin-care products. Glycolic acid is found in some sugar-crops...
from unripe grapes (1864), synthesis of sodium oxalate by heating sodium formate
Sodium formate
Sodium formate, HCOONa, is the sodium salt of formic acid, HCOOH. It usually appears as a white deliquescent powder.-Uses:Sodium formate is used in several fabric dyeing and printing processes...
(1868), hydrolysis of ether to alcohol (1858), synthesis of phenyl-lactic acid (1880), preparation of pyruvic acid
Pyruvic acid
Pyruvic acid is an organic acid, a ketone, as well as the simplest of the alpha-keto acids. The carboxylate ion of pyruvic acid, CH3COCOO−, is known as pyruvate, and is a key intersection in several metabolic pathways....
by the distillation of tartaric acid
Tartaric acid
Tartaric acid is a white crystalline diprotic organic acid. It occurs naturally in many plants, particularly grapes, bananas, and tamarinds; is commonly combined with baking soda to function as a leavening agent in recipes, and is one of the main acids found in wine. It is added to other foods to...
(1881) and the formation of carbostyril from quinoline
Quinoline
Quinoline is a heterocyclic aromatic organic compound. It has the formula C9H7N and is a colourless hygroscopic liquid with a strong odour. Aged samples, if exposed to light, become yellow and later brown...
(1885). His investigations in the aromatic series include isomerism of the cinnamic acid
Cinnamic acid
Cinnamic acid is a white crystalline organic acid, which is slightly soluble in water.It is obtained from oil of cinnamon, or from balsams such as storax. It is also found in shea butter and is the best indication of its environmental history and post-extraction conditions...
s and the synthesis of tyrosine
Tyrosine
Tyrosine or 4-hydroxyphenylalanine, is one of the 22 amino acids that are used by cells to synthesize proteins. Its codons are UAC and UAU. It is a non-essential amino acid with a polar side group...
from phenylalanine
Phenylalanine
Phenylalanine is an α-amino acid with the formula C6H5CH2CHCOOH. This essential amino acid is classified as nonpolar because of the hydrophobic nature of the benzyl side chain. L-Phenylalanine is an electrically neutral amino acid, one of the twenty common amino acids used to biochemically form...
(1882). In 1875, by nitrating benzoic acid
Benzoic acid
Benzoic acid , C7H6O2 , is a colorless crystalline solid and the simplest aromatic carboxylic acid. The name derived from gum benzoin, which was for a long time the only source for benzoic acid. Its salts are used as a food preservative and benzoic acid is an important precursor for the synthesis...
, Erlenmeyer disproved the prevalent opinion that more than three nitrobenzoic acid
Nitrobenzoic acid
Nitrobenzoic acids are derivatives of benzoic acid. Two are commercially important. They are about ten times more acidic than the parent benzoic acid .*2-Nitrobenzoic acid is prepared by oxidation of 2-nitrotoluene....
s exist. In 1861 he invented the conical flask
Erlenmeyer flask
An Erlenmeyer flask, also known as a conical flask, is a widely used type of laboratory flask which features a flat bottom, a conical body, and a cylindrical neck. It is named after the German chemist Emil Erlenmeyer, who created it in 1861...
that bears his name.