Karl Ernst Claus (also Karl Klaus or Carl Claus,23 January 1796 – 24 March 1864) was a Baltic German chemist and naturalist, primarily known as a chemist and discoverer of the chemical element ruthenium, but also as one of the first scientists who applied quantitative methods in botany. He was born in 1796 in Dorpat (Tartu), Livonia, Russia, as the son of a painter. At the age of four, he lost his father and two years later became an orphan. In 1810, he moved to Saint Petersburg and started working as an assistant in a pharmacy. Although he had not received formal education, at age 21, Claus managed to pass the State exam on the pharmacist at the Military Medical Academy of St. Petersburg, becoming the youngest pharmacist in Russia at that time. Later in 1826, he established his own pharmacy in Kazan.
In 1827, Claus became involved, as an assistant of Eduard Friedrich Eversmann, in the botanical research of the steppes of the riversUral and Volga. He later used the collected data in his work "Flora der Wolgagegenden" (Flora of the Volga Region). In 1834, while still studying at the University of Tartu, Claus went into another botanic trip to the trans-Volga steppes – this time with chemistry professor Gebel. The results of this expeditions were published in 1837–1838. In 1828, when he already turned 32, Claus decided to continue his education at the University of Tartu. During the course of his studies, in 1831, he started working as an assistant at the chemical laboratory of the university. He graduated in 1835, and in 1837, defended his PhD thesis on analytical phytochemistry ("Grundzüge der Analytischen Phytochemie") at the University of Tartu.
In 1840, Claus, received a substantial amount of platinum ore samples for his studies from the Saint Petersburg Mint and started working on chemistry and isolation of noble metals, in particular rhodium, iridium, osmium, and to a lesser extent, palladium andplatinum. In 1844, he discovered a new chemical element, which he named ruthenium after Ruthenia, the Latin name of Russia. Claus managed not only to isolate ruthenium, but also determine its atomic weight and chemical properties. He noted the similarity of the chemical properties of ruthenium, rhodium, palladium and platinum and meticulously documented his results. Claus sent samples of new element for analysis to Jöns Jakob Berzelius, who was one of the most renowned scientists in the field of new elements, and thereby became known to European scientists
Ruthenium is a chemical element with symbol Ru and atomic number 44. It is a raretransition metal belonging to the platinum group of the periodic table. Like the other metals of the platinum group, ruthenium is inert to most other chemicals. Ruthenium usually occurs as a minor component of platinum ores; annual production is about 20 tonnes. Most ruthenium produced is used for wear-resistant electrical contacts and the production of thick-film resistors. A minor application of ruthenium is its use in some platinum alloys.The corrosion resistance of titanium is increased markedly by the addition of a small amount of ruthenium. The metal can be plated either by electroplating or by thermal decomposition methods. A ruthenium-molybdenum alloy is known to be superconductive at temperatures below 10.6 K.Ruthenium is exceedingly rare, only the 74th most abundant metal on Earth. This element isgenerally found in ores with the other platinum group metals in the Ural Mountains and in North and South America. Small but commercially important quantities are also found in pentlandite extracted from Sudbury, Ontario, Canada, and in pyroxenite deposits in South Africa. The native form of ruthenium is a very rare mineral (Ir replaces part of Ru in its structure)
Roughly 12 tonnes of ruthenium is mined each year with world reserves estimated as 5,000 tonnes. The composition of the mined platinum group metal (PGM) mixtures varies in a wide range depending on the geochemical formation. Ruthenium, like the other platinum group metals, is obtained commercially as a by-product from nickel and copper mining and processing as well as by the processing of platinum group metal ores. Because of its ability to harden platinum and palladium, ruthenium is used in platinum and palladium alloys to make wear-resistant electrical contacts. In this application, only thin plated films are used to achieve the necessary wear-resistance. Because of its lower cost and similar properties compared to rhodium, the use as plating material for electric contacts is one of the major applications. The thin coatings are either applied by electroplating or sputtering.
Ruthenium dioxide and lead and bismuth ruthenates are used in thick-film chip resistors. These two electronic applications account for 50% of the ruthenium consumption.
Only a few ruthenium alloys are used other than those with other platinum group metals. Ruthenium is often used in small quantities in those alloys to improve some of their properties.The beneficial effect on the corrosion resistance of titanium alloys led to the development of a special alloy containing 0.1% ruthenium. Ruthenium is also used in some advanced high-temperature single-crystal superalloys, with applications including the turbine blades in jet engines. From 1944 onward, the famous Parker 51 fountain pen was fitted with the "RU" nib, a 14K gold nib tipped with 96.2% ruthenium and 3.8% iridium. Ruthenium-centered complexes are being researched for possible anticancer properties.Compared with platinum complexes, those of ruthenium show greater resistance to hydrolysis and more selective action on tumors. NAMI-A and KP1019 are two drugs undergoing clinical evaluation against metastatic tumors and colon cancers. Ruthenium tetroxide is used to expose latent fingerprints by turning to the brown/black ruthenium dioxide when in contact with fatty oils or fats contained in sebaceous contaminants of the print.
Some ruthenium complexes absorb light throughout the visible spectrum and are being actively researched in various, potential, solar energy technologies. These films show promising properties for the use in microchips and for the giant magnetoresistive read element for hard disk drives. Ruthenium was also suggested as a possible material for microelectronics because its use is compatible with semiconductor processing techniques. Many ruthenium based oxides show very unusual properties, such as a quantum critical point behavior, exotic superconductivity, and high temperature ferromagnetism.
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Despite a bad relation with father, forced to study business & botany; this swiss followed his passion for Maths & physics !!!