André S. Dreiding (22 June 1919 in
Zürich
Zurich (; ) is the list of cities in Switzerland, largest city in Switzerland and the capital of the canton of Zurich. It is in north-central Switzerland, at the northwestern tip of Lake Zurich. , the municipality had 448,664 inhabitants. The ...
– 24 December 2013 in
Herrliberg near Zurich) was a
Swiss
Swiss most commonly refers to:
* the adjectival form of Switzerland
* Swiss people
Swiss may also refer to: Places
* Swiss, Missouri
* Swiss, North Carolina
* Swiss, West Virginia
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Other uses
* Swiss Café, an old café located ...
chemist.
[University of Zurich, Institute of Organic Chemistry: André S. Dreiding](_blank)
accessed 2010-07-22 He finished his high school studies in Zürich and then studied at
Columbia University
Columbia University in the City of New York, commonly referred to as Columbia University, is a Private university, private Ivy League research university in New York City. Established in 1754 as King's College on the grounds of Trinity Churc ...
in
New York, where he was awarded BS and MS degrees. After two years as a research assistant at
Hoffmann-La Roche
F. Hoffmann-La Roche AG, commonly known as Roche (), is a Swiss multinational holding healthcare company that operates worldwide under two divisions: Pharmaceuticals and Diagnostics. Its holding company, Roche Holding AG, has shares listed on ...
, he continued postgraduate studies at the
University of Michigan
The University of Michigan (U-M, U of M, or Michigan) is a public university, public research university in Ann Arbor, Michigan, United States. Founded in 1817, it is the oldest institution of higher education in the state. The University of Mi ...
in
Ann Arbor
Ann Arbor is a city in Washtenaw County, Michigan, United States, and its county seat. The 2020 United States census, 2020 census recorded its population to be 123,851, making it the List of municipalities in Michigan, fifth-most populous cit ...
under professor
Werner Emmanuel Bachmann and was awarded his
PhD
A Doctor of Philosophy (PhD, DPhil; or ) is a terminal degree that usually denotes the highest level of academic achievement in a given discipline and is awarded following a course of graduate study and original research. The name of the deg ...
in 1947. He remained at the university until 1949 as Rackham and Lloyd Postdoctoral Fellow. From 1949 to 1954, Dreiding was an assistant professor at
Wayne University, Detroit Institute of Cancer Research. He also temporarily took over Bachmann's teaching and research duties at the University of Michigan after Bachmann's death in 1951 and held them until 1952. In 1954, Dreiding turned to Switzerland and the
University of Zurich
The University of Zurich (UZH, ) is a public university, public research university in Zurich, Switzerland. It is the largest university in Switzerland, with its 28,000 enrolled students. It was founded in 1833 from the existing colleges of the ...
, where he became professor and stayed until his retirement in 1987, after which he was an
emeritus professor
''Emeritus/Emerita'' () is an honorary title granted to someone who retires from a position of distinction, most commonly an academic faculty position, but is allowed to continue using the previous title, as in "professor emeritus".
In some c ...
.
Dreiding Stereomodels
In 1958, Dreiding invented a
molecular model
A molecular model is a physical model of an atomistic system that represents molecules and their processes. They play an important role in understanding chemistry and generating and testing hypotheses. The creation of mathematical models of mole ...
, used primarily in
stereochemistry
Stereochemistry, a subdiscipline of chemistry, studies the spatial arrangement of atoms that form the structure of molecules and their manipulation. The study of stereochemistry focuses on the relationships between stereoisomers, which are defined ...
, named the ''Dreiding Stereomodel''.
It was a so-called
skeletal model, consisting of slim stainless steel tubes and rods. Unlike the older
ball-and-stick model
In chemistry, the ball-and-stick model is a molecular model of a chemical substance which displays both the Molecular geometry, three-dimensional position of the atoms and the chemical bond, bonds between them. The atoms are typically represente ...
s, the atoms were not represented by a ball but rather by the point of intersection of the steel tubes.
[Aldrich Technical Bulletin AL-199: Dreiding Stereomodels](_blank)
/ref> The intersection area was painted with a color to indicate the atom's identity . As the tubes represented the bonds, the model focused on the geometry of the bonds between atoms rather than the atoms themselves. The Dreiding Stereomodel was not the first skeletal model, but was the first to do away with the connectors used in, e.g. John Kendrew's earlier protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...
models. Instead, the Dreiding Stereomodels used a valency of the bonds/steel tubes to facilitate connections; they were either a hollow tube or a slightly narrower solid rod which fit into the tube. A tube not connected to another tube represented a hydrogen
Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter ...
atom and the bond from the other atom (for example carbon
Carbon () is a chemical element; it has chemical symbol, symbol C and atomic number 6. It is nonmetallic and tetravalence, tetravalent—meaning that its atoms are able to form up to four covalent bonds due to its valence shell exhibiting 4 ...
, oxygen
Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), non ...
or nitrogen
Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. ...
) to the hydrogen atoms. This gave the Dreiding Stereomodels a neat look and made the assembly much quicker than earlier skeletal models. They were also quite precise in representing the molecular geometry, so rulers could be used to determine inter-atomic distances and angles.
Availability of Dreiding Stereomodels
The Dreiding Stereomodels were primarily used as a research tool rather than an educational tool for undergraduates. They were widely used by organic chemists, stereochemists and natural products chemists in universities and other research laboratories. The models were sold by Büchi in Europe and by Aldrich in North America. A simpler and cheaper plastic version was later introduced, intended for educational purposes, but never became as widely spread as the original steel version. When molecular modeling software became more readily available in the 1990s, the use of Dreiding Stereomodels declined, production stopped, and the models were discontinued around 2005. However, especially for spectroscopic structure elucidation using NMR and MS, the availability of "hands-on" accurate molecular models remains very valuable. E.g., in natural products chemistry, where structures are often elucidated ab initio, Dreiding Stereomodels can be extremely useful as they allow the rapid assembly of alternative and closely related structures with high geometric precision (e.g., for NOE or 2D NMR interpretations).
Because of their widespread use and availability for >40 years, many researchers and departments still maintain and use their collections. In order to ease the general supply problem for spare parts or entire models, the '
Dreiding Model Exchange
'' was established in 2010 at the University of Illinois at Chicago.
References
{{DEFAULTSORT:Dreiding, Andre
Swiss chemists
Columbia University alumni
University of Michigan alumni
Wayne State University faculty
Academic staff of the University of Zurich
1919 births
2013 deaths