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ROBERT SCHWARZ RALPH E. OESPER University of Cincinnati, Cincinnati, Ohio
E V E R Y inorganic chemist is familiar with the work of
posable and air-sensitive compounds containing silicon chains. I n 1937 he prepared a compound, S ~ , O Cin~ ~ ~ , which ten silicon atoms are directly linked together. Several years later, a compound with no less than 25 links was prepared by this same procedure, namely by thermal treatment of silicon tetrachloride in the quenching tube. When cracked, such long-chain compounds go over into a highly polymeric monochloride, (SiCl),, and ring-shaped silicon chlorides can be obtained as intermediate products. The first member of this new class is SilaClle,which has the structure of a perchlorsilicodecaline. Recently he has devoted considerable attention to silicic esters, and has prepared, for the first time, a large number of these compounds. Since germanium is so closely related to silicon it was hut natural that it too became the subject of many studies. Among the important feats in this field were the preparation of an optically active germanium compound; polygermene (GeH2),; . germanium-nitrogen compounds; heteropoly acids; and numerous organic germanium compounds. Other studies in the inorganic field of special interest dealt with: the peroxides of titanium, zirconium, hafnium, and thorium; peroxy nitric acid; the constitution of chromium peroxide C r 0 ~and the blue perchromates; sulfur tetroxide; the bromine oxides BrOI and BrzO. The preparation of these oxides was accomplished by the reaction of the components in the glow discharge, which thus showed itself to be a real aid in the field of inorganic preparative chemistry. Studies of medico-chemical character yielded especially a new colloid-chemical spinal-fluid reaction in which he employed "siliquid," (a colloidal dispersion of SiO?),and gave new insights into the processes of bone formation. Other researches in the non-inorganic field have dealt with the pyrogenic syntheses of hydrocarbons in the quenching tube. Papers of a more theoretical nature discussed the relation of silicon and carbon chemistry, and the polarity principle in chemistry. A full view of the breadth and depth of his interests can only be gained by an examination of the titles of his papers (about 175) in the indexes of Chemical Abstracts. Among his hooks, the best known are: "Chemie der anorganischeu Komplexverbindungen," which mas translated into French, Spanish, and English (New York, 1923) ; "Anorganische Chemie" ; "Chemisches Praktikum fiir Merliziner." A \-e:y successful teacher, he has trained a large number of competent chemists. ' For biographical details of Meigen, see WEITZ,E., Ber., 68 Professor Schwarz is a Corresponding Member of the A, 29 (1935). Deutsche Akademie der Nat,urforscher and holds the' a S~~OESPE R.RE., , J. CHEM. EDUC.,19,444(1942): SCHWARZ, Alfred Stock Memorial Prize. R., Chem. Ztg. 44, 513 (1920).
(Karl Gottfried) Robert Schwarz, whose long list of publications has made his name a familiar one on both sides of the Atlantic. He was born in Berlin on December 17, 1887, and studied chemistry a t Berlin, Breslau, and Freiburg, where he took his Ph.D. in 1910. H,is dissertation dealt with "Bohnerztone nnd afrikanische Erden" and was prepared under the guidance of Wilhelm Meigen (1873-1934) who was much interested in the geological and crystallographic facets of chemistry.' The choice of this topic was in line with Schwarz's intention to devote himself, after graduation, to ceramics. For this reason, he worked a t first in the Experimental Station of the Staatliche Porzellanmanufaktur in Berlin, but a t the urging of his former teacher Ludwig Gattermann2 he returned to Freibnrg to prepare himself for a teaching career. He qualified as Privatdozent a t Freiburg shortly before the opening of World War 11; his habilitation work dealt with silicon chemistry and was the first of a long series of researches revolving around this element. I n 1922 he was called to the chair of inorganic and analytical chemistry at Freiburg; in 1928 he went to Frankfurt as full professor; in 1934 he moved to Konigsberg. Since 1948 he has been at his present post, professor of inorganic and electrochemistry a t the Technische Hochschule in Aachen. His youthful choice of silicon as a field of research has been pursued faithfully and in various directions. At first, he studied the chemical processes involved in weathering and kaolinization, and this extended series of researches culminated in 1933 with the successful artificial conversion of feldspar into kaolin. The laboratory synthesis of kaolin led to important conclusions regarding the conditions obtaining in the natural formation of this material. Later, silicic acids \%.erethe subject of another extensive series of studies. I t was found, contrary to previous assumptions, that this system is not one which can be definitely represented by the general formula (SiO.JZ.aq. Instead, there are definite polyacids, of which the disilicic acids (H2Si2O& can be obtained in crystalline form. Other researches in. the field of silicate chemistry include studies of the constitution of porcelain; the electrical conductivity of crystalline and vitreous silicates; the processes occurring during the electrolysis of glass a t high temperatures. An entirely different phase of silicon chemi s t is ~ represented by his studies of the easily decom-
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