Franz Hein
Encyclopedia
Franz Hein was a German scientist. One of his notable contributions is in the discovery of π-(arene) complexes of chromium
(I).
, as well as, his college years at the University of Leipzig
. He completed his Ph.D. in 1917 on optical studies of bismuth
and triphenylmethane
derivatives. Hein made Assistant at the University and in 1920 Oberassistent. He continued working on his Habilitation becoming a professor in 1923. With the completion of his Habilitation, Hein went to work on organometallic system electrochemistry. From 1941 to 1965, he worked on main-group-metal derivatives of metal carbonyls. After 1942, Hein moved from Leipzig to the Friedrich Schiller University of Jena where he became the Director of the Institute for Inorganic Chemistry. War came in March 1945 and the University was destroyed. Hein came back to help rebuild towards the end of 1946. Until his retirement, he held a position as a chair in inorganic chemistry until 1959.
(CrCl3) and phenylmagnesium bromide
(C6H5MgBr), Hein created a mixture of compounds that would change the world of chemistry. While unable to determine the structure of his compounds, he started the journey that would unfold the answers. He was able to produce what he called phenylmagnesium salts. Hein denoted them as: (C6H5)5CrX, (C6H5)4CrX, and (C6H5)3CrX. Based on observed chemistry at that time, these were reasonable structures. However, it was later found that the correct structures were of sandwich compound
type complexs. The discovery of ferrocene
and the research done by Zeiss, Tsutsui, and others lead to this structure determination.
Chromium
Chromium is a chemical element which has the symbol Cr and atomic number 24. It is the first element in Group 6. It is a steely-gray, lustrous, hard metal that takes a high polish and has a high melting point. It is also odorless, tasteless, and malleable...
(I).
History
Franz Hein was born in Grötzingen (Baden), Germany. His high school years were spent in LeipzigLeipzig
Leipzig Leipzig has always been a trade city, situated during the time of the Holy Roman Empire at the intersection of the Via Regia and Via Imperii, two important trade routes. At one time, Leipzig was one of the major European centres of learning and culture in fields such as music and publishing...
, as well as, his college years at the University of Leipzig
University of Leipzig
The University of Leipzig , located in Leipzig in the Free State of Saxony, Germany, is one of the oldest universities in the world and the second-oldest university in Germany...
. He completed his Ph.D. in 1917 on optical studies of bismuth
Bismuth
Bismuth is a chemical element with symbol Bi and atomic number 83. Bismuth, a trivalent poor metal, chemically resembles arsenic and antimony. Elemental bismuth may occur naturally uncombined, although its sulfide and oxide form important commercial ores. The free element is 86% as dense as lead...
and triphenylmethane
Triphenylmethane
Triphenylmethane, or triphenyl methane, is the hydrocarbon with the formula 3CH. This colorless solid is soluble in nonpolar organic solvents and not in water. Triphenylmethane has the basic skeleton of many synthetic dyes called triarylmethane dyes, many of them are pH indicators, and some display...
derivatives. Hein made Assistant at the University and in 1920 Oberassistent. He continued working on his Habilitation becoming a professor in 1923. With the completion of his Habilitation, Hein went to work on organometallic system electrochemistry. From 1941 to 1965, he worked on main-group-metal derivatives of metal carbonyls. After 1942, Hein moved from Leipzig to the Friedrich Schiller University of Jena where he became the Director of the Institute for Inorganic Chemistry. War came in March 1945 and the University was destroyed. Hein came back to help rebuild towards the end of 1946. Until his retirement, he held a position as a chair in inorganic chemistry until 1959.
Phenylchromium compounds
With the reaction of anhydrous chromium(III) chlorideChromium(III) chloride
Chromium chloride is a violet coloured solid with the formula CrCl3. The most common form of CrCl3 sold commercially is a dark green hexahydrate with the formula [CrCl24]Cl.2H2O. Two other hydrates are known, pale green [CrCl5]Cl2.H2O and violet [Cr6]Cl3...
(CrCl3) and phenylmagnesium bromide
Phenylmagnesium bromide
Phenylmagnesium bromide, with the simplified formula , is a magnesium-containing organometallic compound. It is so commonly used that it is commercially available as a solution in diethyl ether or tetrahydrofuran . Phenylmagnesium bromide is a Grignard reagent...
(C6H5MgBr), Hein created a mixture of compounds that would change the world of chemistry. While unable to determine the structure of his compounds, he started the journey that would unfold the answers. He was able to produce what he called phenylmagnesium salts. Hein denoted them as: (C6H5)5CrX, (C6H5)4CrX, and (C6H5)3CrX. Based on observed chemistry at that time, these were reasonable structures. However, it was later found that the correct structures were of sandwich compound
Sandwich compound
In organometallic chemistry, a sandwich compound is a chemical compound featuring a metal bound by haptic covalent bonds to two arene ligands. The arenes have the formula CnHn, substituted derivatives and heterocyclic derivatives...
type complexs. The discovery of ferrocene
Ferrocene
Ferrocene is an organometallic compound with the formula Fe2. It is the prototypical metallocene, a type of organometallic chemical compound consisting of two cyclopentadienyl rings bound on opposite sides of a central metal atom. Such organometallic compounds are also known as sandwich compounds...
and the research done by Zeiss, Tsutsui, and others lead to this structure determination.