History of Crystallography at the U. of Zürich

Chemical Crystallography at the University of Zürich

An historical overview by Helmut W. Schmalle and Anthony Linden

Originally published by the Swiss Society of Crystallography, SGK Newsletter No. 41, June, 1996. Reproduced here with updates.

The University of Zürich was founded in 1833. Chemistry research and teaching was started by Karl Löwig shortly thereafter. The Chemistry Laboratory changed its location in 1842, 1887 and 1909. Detailed descriptions of the history and development of chemistry are given in the book "Die Universität Zürich 1833-1983", ed. by the Rektorat der Universität Zürich, in the excellent article "150 Jahre Chemie an der Universität Zürich" by Conrad Hans Eugster (Chimia 37 (1983), 194-237) and in the recently edited booklet "Chemistry at the University of Zurich" (ed. M. Volkan Kisakürek).

The fast development of chemical research in Zürich, which is connected with the famous Alfred Werner (1893-1919 head of the Chemistry Laboratory) and Paul Karrer (active between 1919 and 1959), made it necessary to subdivide the Institute of Chemistry. The Physikalisch-chemisches Institut (PCI) was founded in 1930. In 1959 the Anorganisch-chemisches Institut (ACI) and Organisch-chemisches Institut (OCI) were generated from the former Chemisches Institut.

The history of crystallography in Zürich goes back to the year 1856 and is directly connected with the ETH (Eidgenössische Technische Hochschule), where famous crystallographers such as Paul Niggli, Werner Nowacki, Fritz Laves and Heinrich Heesch have made important contributions. Johann Jakob Burckhard gives an impressive and detailed insight into this period of time with the book "Die Symmetrie der Kristalle", ed. Birkhäuser, Basel, Boston, Berlin, 1988. An overview of crystallography in Zürich, which focussed on the high standard of crystallographic research and teaching at the ETH, was presented in the SGK Newsletter No. 40, (Jan. 1996) by Volker Gramlich and Walter Steurer. At the University of Zürich, both the OCI and the ACI use small molecule X-ray crystallography as an analytical tool and the Biochemisches Institut established a macromolecular crystallography research group under the direction of Markus Grütter in 1997.

Crystallography in the Institute for Inorganic Chemistry

Fundamental knowledge and the necessity for increasing employment of X-ray crystallography was brought to the ACI in 1966 when Hans Rudolf Oswald was appointed professor and director of the institute. His research areas cover, among others, reactivity of solids, coordination compounds, catalysis, thermal analysis, and powder- and single-crystal analyses of inorganic crystal structures. A Picker FACS-1 4-circle diffractometer was acquired in 1969, and the crystallographic calculations were initially performed on an IBM-1620 computer of the University. In 1982 an Enraf-Nonius CAD-4 diffractometer was installed in connection with a PDP-11/34 computer system. Today a u-Vax cluster system (a micro-Vax 3100, a micro-Vax 3100 station and a micro-Vax 3520 graphics station) and a SGI Indy, connected via the Internet to the University's computer centre, are available for the ACI service crystallography. Until 1990, the position of the service crystallographer in the ACI had been financially supported by the Swiss National Science Foundation within the framework of Hans Rudolf Oswald's research projects and was occupied by several postdocs from different countries (e.g. Geoffrey Jameson, New Zealand, and Wolfgang Bensch, Germany). Since October 1990, service crystallography has been a permanent position at the ACI held by Helmut Schmalle, supporting the chemical education of students, PhD students and postdocs with single crystal X-ray structure analyses of varying complexity. Erich Dubler offers courses in chemical X-ray crystallography for all students of chemistry and biochemistry.

The single crystal 4-circle diffractometer (Enraf-Nonius CAD-4) served several research groups for 16 years: Inorganic solid state chemistry and reactivity of solids (Hans Rudolf Oswald), Perovskites and related oxide systems (Armin Reller, now at University of Hamburg), Bio-Inorganic chemistry (Erich Dubler), Copper(I)-thiolates, lipoic acid- and squaric acid-complexes (Markus Baumgartner, Erich Dubler), Molecular based magnetic materials (2-D and 3-D polymeric network structures) (Silvio Decurtins), Modulated tin-tungsten bronzes (EM group, John Ralph Günter), Iron-clusters, metal coordination with polyalcohols (collaboration with Kaspar Hegetschweiler of the ETH, now at the University of Saarbrücken).

The strong demand for crystal structure analyses in the field of organometallic chemistry in Heinz Berke's group (in the ACI since 1988) made it necessary for that group to acquire and run its own diffractometers (Siemens P3 and the old Nicolet R3 from the OCI upgraded to a Siemens P4), the crystallographic work usually being carried out by postdocs.

All of the institute's diffractometers were replaced in 1998 by a Stoe IPDS system, which is managed by Helmut Schmalle. This acquisition greatly increased the throughput of structures. A second identical instrument was added in 1999 for use by the research group of Roger Alberto.

Some examples from the last five years show a cross-section of the research activities in connection with X-ray structure determinations for different research groups at the ACI.

Crystallography in the Institute for Organic Chemistry

In planning for the move to the new Irchel campus in 1979, the OCI decided to include X-ray crystallography in its comprehensive range of analytical services. Until then, structure determinations had usually been carried out through the kind auspices of F. Hoffmann-La Roche. Jost Bieri was charged with the task of setting up a state-of-the-art service laboratory, and in late 1980 the first service structures were turned out using a Nicolet R3 diffractometer with a low-temperature attachment, Huber Weissenberg and precession cameras and a Data General Eclipse computer. J. Bieri remained manager of the facility, while most of the structural analyses were conducted by Roland Prewo. J. Bieri retired in 1987 after a long period of illness and R. Prewo moved to Stuttgart in 1988.

The X-ray Crystallography Facility was combined with the institute's computational services in 1988 to form the Laboratory for Computer Chemistry and X-ray Structure Analysis, administratively headed by Roland Kunz. The position of service crystallographer was then briefly filled by Beverly Vincent until he was enticed to join Molecular Structure Corporation in the middle of 1989. Since October 1989, Anthony Linden has managed the laboratory, ably assisted by one laboratory technician. The Eclipse computer was replaced by a Vax 6320 in 1989, while a Rigaku AFC5R diffractometer with a rotating anode generator and a low-temperature attachment was purchased in 1991 to replace the Nicolet R3. These upgrades substantially increased the annual productivity of the laboratory. The Nicolet diffractometer was transferred to the ACI where it was upgraded to a Siemens P4 and saw several more years of very active service until 1998. An SGI Indigo-2 (R10000) was made available to the laboratory in 1996, while the Vax computer ended its service at the end of 1998, being replaced by an SGI Origin 200. At the end of 2000, the Rigaku AFC5R diffractometer was replaced by a Nonius KappaCCD diffractometer on a FR590 sealed tube generator, thereby launching the laboratory into the modern age of CCD detectors with the incumbent dramatic increase in sample throughput capacity.

With these technological advances, the standard of the service has been improved steadily over the years. Improvements in structure solving and refinement software are well known to all crystallographers, but particular attention has also been paid to the presentation of the results at the end of the analysis. As a service laboratory, it is the results which are of prime interest to our customers, and the ease with which they can be utilised is a very important aspect of our service. The tables, diagrams and much of the publication-ready experimental details are automatically produced as Word documents which can be retrieved from a file server. This permits easy inclusion of these details directly into theses and publications, which saves time and reduces the chances of typographical errors or omissions.

The X-ray Crystallography Facility serves the needs of the following research groups within the OCI: heptalene chemistry and asymmetric induction in transition-metal catalysed transformations (Hans-Jürgen Hansen), natural product chemistry, ring enlargement reactions and mass spectroscopy (Manfred Hesse), bio-organic chemistry (John Robinson), heterocyclic compounds and peptides (Heinz Heimgartner), computational chemistry and molecular dynamics (J. Hutter), organophosphorus and phytochemistry (Peter Rüedi), and organosilicon chemistry (Stefan Bienz). The research groups of André Dreiding, Conrad Eugster, Max Viscontini, Wolfgang von Philipsborn (now Professors Emeriti), Andreas Vasella (now at the ETH-Zürich), and Wolf-Dieter Woggon (now at Universität Basel) also made use of the service in earlier years. More recently, the facility has participated in collaborative research projects being conducted jointly with other groups from within Switzerland and from countries as far afield as Australia, Singapore, Canada, Germany, Spain, Bulgaria, Poland and Hungary, and occasionally provides structure determination services for some Swiss pharmaceutical companies.

A list of publications shows some of the crystallographic work being conducted in the OCI.

Last update: 1-November-2000/ AL