Schmidt, Gerhard

HANS MATTER, STEFAN GOSSREGEN, FRIEDEMANN SCHMIDT, GERHARD HESSLER, THORSTEN NAUMANN, and KARL-HEINZ BARINGHAUS... 

V. Gerhard, H. Schirra, G. Wagner, H. Schmidt, in Extended Abstract of the Fourth Saar-Lor-Lux Meeting on Functional Advanced Materials (Ed. G. Kugel, CLOES-SUPELEC, Technopole de Metz/France), November 1994. 

The development of the principles of solid-state reactions of substituted cinnamic acids was pioneered by Gerhard M. J. Schmidt. The trans-SLcid was found to be polymorphic, and three different crystal forms (designated a, and 7) were identified by him. The finding that the nature of the cyclobutane derivatives formed by the solid-state photochemical reaction on crystals of frans-cinnamic acid depend on which polymorph is irradiated was of great interest. The products of the photo-... 

Thorium was discovered in 1828 by Swedish chemist Jons Jakob Berzelius (1779—1848). At the time, Berzelius did not realize that thorium was radioactive. That fact was discovered 70 years later, in 1898, by Polish-French physicist Marie Curie (1867—1934) and English chemist Gerhard C. Schmidt (1864-1949). 

At the time Berzelius made his discovery, the concept of radioactivity was unknown. Radioactivity refers to the process by which an element spontaneously breaks down and gives off radiation. In that process, the element often changes into a new element. One of the first scientists to study radioactivity was Marie Curie. She and Gerhard C. Schmidt announced at almost the same time in 1898 that Berzelius thorium was radioactive. 

We are indebted to Dr. Gerhard Schmidt for his kindness in reading and criticizing this section. 

When I was young, solid-state phase changes and chemical reactions were regarded more as a nuisance than as an area worthy of serious study and attention. It was the topochemical approach to solid-state chemical reactions, pioneered by Gerhard Schmidt, that transformed the subject for me and for many others. The textbook example is the photochemical dimerization of (fj-cinnamic acids in solution such compounds yield mixtures of the various possible stereoisomeric products, but irradiation of a particular crystal leads to a single product, or to no reaction, depending on the crystal structure [40]. Thus, one can determine the relative positions of the atoms before the reaction and after it, and haice deduce the metrical relationships that needed to be satisfied for reaction to proceed. In the meantime we have learned that not all chemical reactions in solids are topochemical. Some proceed not in the ordered bulk of the crystal but at defects, on the surface, or at other irregularities. 

KARL-HEINZ BARINGHAUS, GERHARD HESSLER, HANS MATTER, and FRIEDEMANN SCHMIDT... 

Huneck S, Schmidt J (1995) Neue Flechtenanalysen aus verschiedenen Ver-wandtschaftskreisen. Flechten Follmann. Contrib to Lichenology in Honour of Gerhard Follmann. Geobot and Phytotaxonomical Study Group, Cologne 15... 

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