Otto Ruff RALPH E. OESPER
University of Cincinnati, Cincinnati, Ohio
U
NPROFITABLE ventures in match manufacture and shale oil distillation by Otto Ruff's grandfather and father convinced the family that a young man in moderate circumstances had better exercise his chemical talents in a profession giving more promise of a sure livelihood. However, three years' service as apothecary apprentice was enough; Ruff felt that he was made for better things than vending packaged remedies and rolling pills. He decided to risk his future, and devote himself to chemistry. He chose the University of Berlin because Emil Fischer was there, but, of course, Ruff had no direct contact with the great man for several years. Ruff's manipulative skill attracted attention; after only one semester he was made assistant to Piloty, under whom he completed his doctorate in 1897. Ruff passed the state examination in pharmacy in 1896, and during his studentship supported himself, for the most part, by clerking in drugstores. The young doctor stayed on a t Berlin, but now as assistant to Fischer. He changed his field of research from nitroso compounds to sugars, and achieved considerable success, particularly in his studies of the degradation of these carbohydrates by oxidation. Ruff's habilitation lecture in 1901 was entitled, "Synthesis in the Sugar Groups," and he seemed destined to become another in that great company of organic chemists that issued from Fischer's influence. This was not to be; and none other than Emil Fischer was responsible for a sudden and final change in Ruff's interests. A good organic chemist was forced into the inorganic field, and the chemical world is doubtless far richer. From time to time Ruff took on problems brought to him by the organic industries. His work on carbazole was so good that a tempting offerto enter the full-time employ of one of the big dye corporations followed. How often have brilliant young professors been confronted with this situation? Ruff's mind was made up for him by Fischer, who offered him the headship of the inorganic division, but with the stipulation that Ruffand his assistants not only teach inorganic chemistry but do their research in that field. Fischer fully realized that the over-emphasis on the organic side was a real danger to the healthy advance of German chemistry. Faced with the necessity of finding new fields of investigation, Ruff felt his way cautiously, getting inspiration and suggestions wherever he could. Always interested in materials rather than theories, he naturally turned to the preparative side, and soon had to his credit a series of interesting new compounds. The
most important chapter in his career isused from such simple beginnings. The determination of the titanium content of silicates was based on the volatilization of the silicon, as SiR, when a mixture of the oxides is treated with hydrofluoric and sulfuric acids. As titanium tetrafluoride had not been prepared, the method could not be considered certain until actual tests of the now volatility of this compound had been made. Ruff prepared TiF, by heating the tetrachloride with anhydrous hydrofluoric acid, whose preparation in those days was in itself quite a feat. The reaction went so smoothly that i t was successfully tried on many other chlorides. In time, Ruff developed other methods of preparing fluorides, and eventually became the world authority on inorganic compounds of this element. Some sixty new fluorides were made in his laboratory and others were studied there. Much of this involved beautiful low-temperature technic. His biographer Huckel,' points out that although RuF6was prepared by Ruff, his efforts to make RuFn were not successful, which really was too bad, because the formula would have spelled his name! Ruff was an expert in demonstration experiments and his illustrated survey of fluorine chemistry before the German Chemical Society in 1936 will long be remembered as a model of this type of l e c t ~ r e . ~ Like Moissan, the isolator of fluorine, Ruff also contributed much to high-temperature studies. Th: production of good stoneware, the manufacture of ceramic vessels for high-temperature work, synthetic gems, the various forms of carbon, electrolysis of fused salts, gas explosions in coal mines, are typical instances of his broad range of interests. In 1904, he went to Danzig to direct work in inorganic and technological chemistry; in 1916 he was called to the Technical High School a t Breslau, and from 1933 to his retirement in 1936 be was also on the faculty of the University of Breslau. Ruff was purely a synthetic chemist; his chief aim was to make and study the physical properties of compounds. Werner's coordination theory, and similar concepts, and the application of physical chemistry appealed to him slightly if a t all. He felt that theory had fallen far behind the experimental data of the inorganic field. The niceties of analytical chemistry were passed over; to him analysis was merely a means to an end. He was a "lone wolf," and founded no school. Honors came to him in full measure, both in Germany and abroad, but the 300 papers that came from his laboratory constitute his lasting memorial.
' HOCKEL.Ber.. 73A, 125 (1940).
' Rum. Chem. Ztg., 60, 873 (1936)
