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Richard Herz
Richard Herz (July 21, 1867 – November 18, 1936) was a German chemist. He discovered the Herz reaction. He studied chemistry at the University of Heidelberg, at the Technical College of Berlin and at the University of Berlin, and earned his PhD in 1891. From 1892 he was employed by the Leonhardt und Co. Works in Mühlheim am Main and in 1895 he joined a British firm, Levinstein, in Manchester. He was recruited by Cassella in 1899, and played a key role in the company's development of sulfur dye Sulfur dyes are the most commonly used dyes manufactured for cotton in terms of volume. They are inexpensive, generally have good wash-fastness, and are easy to apply. Sulfur dyes are predominantly black, brown, and dark blue. Red sulfur dyes are u ...s. He received power of procuration in 1918 and became deputy director in 1925. He retired in 1931.Winfried R. Pötsch, Annelore Fischer, Wolfgang Müller: ''Lexikon bedeutender Chemiker'', Harri Deutsch 1989, , p. 200. References 1867 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herz Reaction
The Herz reaction, named after the chemist Richard Herz, is the chemical conversion of an aniline-derivative (1) to a so-called Herz salt (2) with disulfur dichloride, followed by hydrolysis of this Herz salt (2) to the corresponding sodium thiolate (3): Applications Benzothiadiazoles The Herz salts hydrolyze to give aminothiophenols, which are suitable for diazotization, giving Benzothiadiazoles. Benzothiazoles The sodium thiolate can be converted to an intermediate zinc mercaptide with zinc sulfate, followed by reaction of the mercaptide with for instance benzoyl chloride, forming a 1,3-benzothiazole. Dyes Aniline 5 is converted to compound 6, in three steps; # conversion to an ortho- aminothiol through the Herz-reaction (aniline 5 and disulfur dichloride), followed by # conversion to an ortho-aminoarylthioglycolacid and # conversion of the aromatic amine function to a nitrile via the Sandmeyer reaction. # In a last step the nitrile is hydrolysed resulting in 6. This com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemische Berichte
''Chemische Berichte'' (usually abbreviated as ''Ber.'' or ''Chem. Ber.'') was a German-language scientific journal of all disciplines of chemistry founded in 1868. It was one of the oldest scientific journals in chemistry, until it merged with ''Recueil des Travaux Chimiques des Pays-Bas'' to form ''Chemische Berichte/Recueil'' in 1997. ''Chemische Berichte/Recueil'' was then merged with other European journals in 1998 to form ''European Journal of Inorganic Chemistry''. History Founded in 1868 as ''Berichte der Deutschen Chemischen Gesellschaft'' (, CODEN BDCGAS), it operated under this title until 1928 (Vol. 61). The journal was then split into: * ''Berichte der Deutschen Chemischen Gesellschaft, A: Vereins-Nachrichten'' (, CODEN BDCAAS), and * ''Berichte der Deutschen Chemischen Gesellschaft, B: Abhandlungen'' (, CODEN BDCBAD). Vol. 78 and 79 (1945–1946) were omitted and not published due to World War II. The journal was renamed ''Chemische Berichte'' (, CODEN CHBEAM) in 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Heidelberg
} Heidelberg University, officially the Ruprecht Karl University of Heidelberg, (german: Ruprecht-Karls-Universität Heidelberg; la, Universitas Ruperto Carola Heidelbergensis) is a public research university in Heidelberg, Baden-Württemberg, Germany. Founded in 1386 on instruction of Pope Urban VI, Heidelberg is Germany's oldest university and one of the world's oldest surviving universities; it was the third university established in the Holy Roman Empire. Heidelberg is one of the most prestigious and highly ranked universities in Europe and the world. Heidelberg has been a coeducational institution since 1899. The university consists of twelve faculties and offers degree programmes at undergraduate, graduate and postdoctoral levels in some 100 disciplines. The language of instruction is usually German, while a considerable number of graduate degrees are offered in English as well as some in French. As of 2021, 57 Nobel Prize winners have been affiliated with the city o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Technical University Of Berlin
The Technical University of Berlin (official name both in English and german: link=no, Technische Universität Berlin, also known as TU Berlin and Berlin Institute of Technology) is a public research university located in Berlin, Germany. It was the first German university to adopt the name "Technische Universität" (Technical University). The university alumni and professor list includes several US National Academies members, two National Medal of Science laureates and ten Nobel Prize laureates. TU Berlin is a member of TU9, an incorporated society of the largest and most notable German institutes of technology and of the Top International Managers in Engineering network, which allows for student exchanges between leading engineering schools. It belongs to the Conference of European Schools for Advanced Engineering Education and Research. The TU Berlin is home of two innovation centers designated by the European Institute of Innovation and Technology. The university is labeled ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Berlin
Humboldt-Universität zu Berlin (german: Humboldt-Universität zu Berlin, abbreviated HU Berlin) is a German public research university in the central borough of Mitte in Berlin. It was established by Frederick William III on the initiative of Wilhelm von Humboldt, Johann Gottlieb Fichte and Friedrich Ernst Daniel Schleiermacher as the University of Berlin () in 1809, and opened in 1810, making it the oldest of Berlin's four universities. From 1828 until its closure in 1945, it was named Friedrich Wilhelm University (german: Friedrich-Wilhelms-Universität). During the Cold War, the university found itself in East Berlin and was ''de facto'' split in two when the Free University of Berlin opened in West Berlin. The university received its current name in honour of Alexander and Wilhelm von Humboldt in 1949. The university is divided into nine faculties including its medical school shared with the Freie Universität Berlin. The university has a student enrollment of around ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cassella
Cassella AG, formerly Leopold Cassella & Co. and Cassella Farbwerke Mainkur AG, commonly known as Cassella, was a German chemical and pharmaceutical company with headquarters in Frankfurt am Main. Founded in 1798 in the Frankfurt Jewish Alley by Leopold Cassella, Cassella operated as an independent company until 1995 and was one of many predecessor companies of today's Sanofi. Its main products were dyes, drugs, cosmetics and various other chemical products. From 1949 Cassella focused increasingly on pharmaceuticals and cosmetics rather than its former primary focus, dyes. Much of its history is closely associated with the Gans family, a prominent family of industrialists and philanthropists and former owners of Cassella. History The company was founded as a spice store inside the Frankfurt Jewish Alley in 1798 by the Jewish businessman Leopold Cassella and his brother-in-law Isaac Elias Reiss, and was originally named ''Cassel & Reiss''. In its early years, the company f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfur Dye
Sulfur dyes are the most commonly used dyes manufactured for cotton in terms of volume. They are inexpensive, generally have good wash-fastness, and are easy to apply. Sulfur dyes are predominantly black, brown, and dark blue. Red sulfur dyes are unknown, although a pink or lighter scarlet color is available. Chemistry Sulfur linkages are the integral part of chromophore in sulfur dyes. They are organosulfur compounds consisting of sulfide (–S–), disulfide (–S–S–) and polysulfide (–Sn–) links in heterocyclic rings. They feature thiazoles, thiazone, thianthrene, and phenothiazonethioanthrone subunits. Being nonionic, sulfur dyes are insoluble in water. Process Dyeing includes a few stages, viz. reduction, dyeing, washing, oxidation, soaping, and final washing. The anion is developed on reducing and solubilising at boil when it shows affinity for cellulose. Sodium sulfide (Na2S), the reducing and solubilising agent, performs both reduction and solubilisation, produ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1867 Births
Events January–March * January 1 – The Covington–Cincinnati Suspension Bridge opens between Cincinnati, Ohio, and Covington, Kentucky, in the United States, becoming the longest single-span bridge in the world. It was renamed after its designer, John A. Roebling, in 1983. * January 8 – African-American men are granted the right to vote in the District of Columbia. * January 11 – Benito Juárez becomes Mexican president again. * January 30 – Emperor Kōmei of Japan dies suddenly, age 36, leaving his 14-year-old son to succeed as Emperor Meiji. * January 31 – Maronite nationalist leader Youssef Bey Karam leaves Lebanon aboard a French ship for Algeria. * February 3 – ''Shōgun'' Tokugawa Yoshinobu abdicates, and the late Emperor Kōmei's son, Prince Mutsuhito, becomes Emperor Meiji of Japan in a brief ceremony in Kyoto, ending the Late Tokugawa shogunate. * February 7 – West Virginia University is established in Morgantown, West Virginia. * Febru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1943 Deaths
Events Below, the events of World War II have the "WWII" prefix. January * January 1 – WWII: The Soviet Union announces that 22 German divisions have been encircled at Stalingrad, with 175,000 killed and 137,650 captured. * January 4 – WWII: Greek-Polish athlete and saboteur Jerzy Iwanow-Szajnowicz is executed by the Germans at Kaisariani. * January 11 ** The United States and United Kingdom revise previously unequal treaty relationships with the Republic of China (1912–1949), Republic of China. ** Italian-American anarchist Carlo Tresca is assassinated in New York City. * January 13 – Anti-Nazi protests in Sofia result in 200 arrests and 36 executions. * January 14 – January 24, 24 – WWII: Casablanca Conference: Franklin D. Roosevelt, President of the United States; Winston Churchill, Prime Minister of the United Kingdom; and Generals Charles de Gaulle and Henri Giraud of the Free French forces meet secretly at the Anfa Hotel in Casablanca, Morocco, to plan the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
19th-century German Chemists
The 19th (nineteenth) century began on 1 January 1801 ( MDCCCI), and ended on 31 December 1900 ( MCM). The 19th century was the ninth century of the 2nd millennium. The 19th century was characterized by vast social upheaval. Slavery was abolished in much of Europe and the Americas. The First Industrial Revolution, though it began in the late 18th century, expanding beyond its British homeland for the first time during this century, particularly remaking the economies and societies of the Low Countries, the Rhineland, Northern Italy, and the Northeastern United States. A few decades later, the Second Industrial Revolution led to ever more massive urbanization and much higher levels of productivity, profit, and prosperity, a pattern that continued into the 20th century. The Gunpowder empires, Islamic gunpowder empires fell into decline and European imperialism brought much of South Asia, Southeast Asia, and almost all of Africa under Colonialism, colonial rule. It was also marked ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cassella People
Cassella AG, formerly Leopold Cassella & Co. and Cassella Farbwerke Mainkur AG, commonly known as Cassella, was a German chemical industry, chemical and pharmaceutical industry, pharmaceutical company with headquarters in Frankfurt am Main. Founded in 1798 in the Frankfurter Judengasse, Frankfurt Jewish Alley by Leopold Cassella, Cassella operated as an independent company until 1995 and was one of many predecessor companies of today's Sanofi. Its main products were dyes, Pharmaceutical drug, drugs, cosmetics and various other chemical products. From 1949 Cassella focused increasingly on pharmaceuticals and cosmetics rather than its former primary focus, dyes. Much of its history is closely associated with the Gans family, a prominent family of industrialists and philanthropists and former owners of Cassella. History The company was founded as a spice store inside the Frankfurter Judengasse, Frankfurt Jewish Alley in 1798 by the Jewish businessman Leopold Cassella and his brothe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
