chemistry inventions

Chemistry Inventions, Discoveries and Patents

Invention
Inventor
Year
Short Description
Patent No.




Aluminum
Charles Hall
1888
Electrolytic method for extracting pure aluminum from its ore
US400,665




Anti-Leukemia Drugs
Gertrude Elion
1955
2-Amino-6-Mercaptopurine, or "Purinethol," the first major medicine to fight leukemia.
US2,884,667




Bakelite
Leo Baekeland
1907
Nonflammable material that was cheaper and more versatile than other known plastics. Used in everything from engine parts to jewelry to electronics.
US942,699




Bromine Extraction
Herbert Dow
1891
Entirely new method of extracting bromine from prehistoric brine.
US11,232




Carborundum
Edward Acheson
1897
Highly effective abrasive used in manufacturing.
US492,767US615,648




Catalytic Cracking
William Burton
1912
First commercially successful process for cracking crude oil into gasoline and other products.
US1,049,667




Cortisone (Synthetic)
Lewis Sarett
1945
Synthetic version of the hormone cortisone: an effective treatment against rheumatoid arthritis.
US2,462,133




Dynamite
Alfred Nobel
1866
Combination of nitroglycerin absorbed by a porous substance that enabled an easily handled, solid yet malleable explosive.
US78,317




HDPE and Polypropylene Plastics
Robert BanksPaul Hogan
1956
A method to produce HDPE in a low pressure situation.
US2,825,721




Isothiocyanate Compounds
Joseph BurckhalterRobert Seiwald
1958
Identification of antigens through the synthesis of fluorescein isothiocyanate (FITC)
US2,937,186




Kevlar
Stephanie Kwolek
1971
Polymer fiber five times stronger than the same weight of steel for bullet-resistant vests and many other applications.
US3,819,587




Nystatin
Rachel BrownElizabeth Hazen
1952
Antifungal / antibiotic cure for many disfiguring and disabling fungal infections of the skin, mouth, throat, and intestinal tract.
US2,797,183




Oral Contraceptives
Frank Colton
1951
Enovid, the first oral contraceptive
US2,691,028




Pasteurization
Louis Pasteur
1862
Process of heating food for the purpose of killing harmful organisms such as bacteria, viruses, protozoa, molds, and yeasts.
US135,245




Peanut Products
George Washington Carver
1923
Peanut cosmetics, paints and stains.
US1,522,176US1,541,478




Penicillin Production
Andrew Moyer
1945
By culturing the penicillium mold in a culture broth comprising corn steep liquor and lactose, penicillin yields could be increased many fold
US2,442,141US2,443,989




Penicillin Production
John Sheehan
1957
The first rational total and general synthesis of natural penicillin.
US3,939,151




Pentothal
Donalee TabernErnest Volwiler
1936
General anesthetic Pentothal, one of the most important agents in modern medicine
US2,153,729




pH Meter
Arnold Beckman
1935
Apparatus for testing acidity
US2,058,761




Photography
George Eastman
1885
The first commercial film was cut in narrow strips and wound on a roller device patented by Eastman and Walker
US226,503




Polymerase Chain Reaction (PCR)
Kary Mullis
1983
PCR amplifies specific DNA sequences from very small amounts of complex genetic material. The amplification produces an almost unlimited number of highly purified DNA molecules suitable for analysis or manipulation. Essential for screening genetic and infectious diseases, genetics, medicine, forensics and paternity testing.
US4,683,202




Polyurethane
William HanfordDonald Holmes
1939
Process that reacts polyols and related hydroxy compounds with di-isocyanates for making the multipurpose material polyurethane. Uses: upholstery, heat-insulation, artificial hearts, safety padding in modern automobiles and carpeting.
US2,284,896




Polyvinyl Chloride (PVC)
Waldo Semon
1926
A method to plasticize PVC by blending it with various additives rendering it a more flexible and more easily processed material that soon has become the world's second-best-selling plastic.
US1,929,453US2,188,396




Prozac
Bryan MolloyKlaus Schmiegel
1974
A class of aryloxyphenylpropylamines, which includes the active ingredient in Prozac®, the most widely used antidepressant.
US4,314,081




Scotchgard (TM) Textile Protector
Patsy ShermanSamuel Smith
1956
One of the most widely used and valuable products in stain repellency and soil removal.
US3,574,791




Synthetic Rubber
Julius Nieuwland
1928
A process by which monovinylacetylene were treated with hydrogen chloride and the resulting chloroprene polymerized, neoprene would result.
US1,811,959




Synthetic Rubber
Wallace Carothers
1930
A process that enabled the large-scale production of Neoprene, the first commercially successful synthetic rubber.
US2,130,947US2,130,948




Tagamet - Cimetidine
Graham DurantJohn EmmettCharon Ganellin
1974
Tagamet is one of the world's most essential drugs for its ability to heal stomach ulcers without surgery.
US3,950,333US4,024,271




Teflon
Roy Plunkett
1938
A synthetic fluoropolymer which has an extremely low coefficient of friction against polished steel and is used as a non-stick coating for pans and other cookware. It is very non-reactive, and so is often used in containers and pipework for reactive and corrosive chemicals.
US2,230,654




Tetracycline
Lloyd Conover
1953
Tetracycline one of the most prescribed broad spectrum antibiotic and is the drug of choice for a number of serious bacterial infections.
US2,699,054




Titanium
William Kroll
1932
"Kroll Process" enables the production of metallic ductile titanium by combining titanium tetrachloride with calcium.
US2,205,854




Transparent Silica
James Hyde
1934
A process for making fused silica, an impurity-free glass, using a method called “frame hydrolysis.”
US2,272,342




Vaccine for Hepatitis B
Baruch BlumbergIrving Millman
1963
Blumberg discovered an antigen in 1963 that detected the presence of hepatitis B in blood samples. Blumberg and Millman developed later a test that identified hepatitis B in blood samples and developed a vaccine against the virus.
US3,636,191US3,872,225




Vitamins
Max Tishler
1940
Process for the synthesis of riboflavin that would permit economical, large-scale production of the essential vitamin (B2).
US2,261,608US2,404,199




Vitamins
Robert Williams
1933
Isolation of vitamin B1 (thiamine) from a syrup of rice polishings.
US2,049,988




Vulcanization of Rubber
Charles Goodyear
1839
A process by which rubber is mixed with sulfur and heated - what came to be known as vulcanization strengthened rubber. Uses: a vast variety of industrial uses, including, eventually, automobile tires.
US3,633

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Ionic liquid | 1-butyl-3-methylimidazolium salts

Ionic liquid
An ionic liquid is a liquid that contains essentially only ions. Some ionic liquids, such as ethylammonium nitrate, are in a dynamic equilibrium where at any time more than 99.99% of the liquid is made up of ionic rather than molecular species. In the broad sense, the term includes all molten salts, for instance, sodium chloride at temperatures higher than 800 °C. Today, however, the term "ionic liquid" is commonly used for salts whose melting point is relatively low (below 100 °C). In particular, the salts that are liquid at room temperature are called room-temperature ionic liquids, or RTILs.


1-butyl-3-methylimidazolium salts or bmim
//
History
Whereas the date of discovery, as well as discoverer, of the "first" ionic liquid is disputed, one of the earlier known ionic liquids was [EtNH3]+ [NO3]- (m.p. 12 °C), the synthesis of which was published in 1914.Much later, series of ionic liquids based on mixtures of 1,3-dialkylimidazolium or 1-alkylpyridinium halides and trihalogenoaluminates, initially developed for use as electrolytes, were to follow.An important property of the imidazolium halogenoaluminate salts was that they were tuneable – viscosity, melting point and the acidity of the melt could be adjusted by changing the alkyl substituents and the ratio of imidazolium or pyridinium halide to halogenoaluminate.
A major drawback was their moisture sensitivity and, though to a somewhat lesser extent, their acidity/basicity, the latter which can sometimes be used to an advantage. In 1992, Wilkes and Zawarotko reported the preparation of ionic liquids with alternative, 'neutral', weakly coordinating anions such as hexafluorophosphate ([PF6]-) and tetrafluoroborate ([BF4])-, allowing a much wider range of applications for ionic liquids It was not until recently that a class of new, air- and moisture stable, neutral ionic liquids, was available that the field attracted significant interest from the wider scientific community.
More recently, people have been moving away from [PF6]- and [BF4]- since they are highly toxic, and towards new anions such as bistriflimide [(CF3SO2)2N]- or even away from halogenated compounds completely. Moves towards less toxic cations have also been growing, with compounds like ammonium salts (such as choline) being just as flexible a scaffold as imidazole.
Characteristics
Ionic liquids are electrically conductive and have extremely low vapor pressure. (Their noticeable odours are likely due to impurities.) Their other properties are diverse. Many have low combustibility, excellent thermal stability, a wide liquid range, and favorable solvating properties for diverse compounds. Many classes of chemical reactions, such as Diels-Alder reactions and Friedel-Crafts reactions, can be performed using ionic liquids as solvents. Recent work has shown that ionic liquids can serve as solvents for biocatalysis . The miscibility of ionic liquids with water or organic solvents varies with sidechain lengths on the cation and with choice of anion. They can be functionalized to act as acids, bases or ligands, and have been used as precursor salts in the preparation of stable carbenes. Because of their distinctive properties, ionic liquids are attracting increasing attention in many fields, including organic chemistry, electrochemistry, catalysis, physical chemistry, and engineering; see for instance magnetic ionic liquid.
Despite their extremely low vapor pressures, some ionic liquids can be distilled under vacuum conditions at temperatures near 300 °C.Some ionic liquids (such as 1-butyl-3-methylimidazolium nitrate) generate flammable gases on thermal decomposition. Thermal stability and melting point depend on the components of the liquid.
The solubility of different species in imidazolium ionic liquids depends mainly on polarity and hydrogen bonding ability. Simple aliphatic compounds are generally only sparingly soluble in ionic liquids, whereas olefins show somewhat greater solubility, and aldehydes can be completely miscible. This can be exploited in biphasic catalysis, such as hydrogenation and hydrocarbonylation processes, allowing for relatively easy separation of products and/or unreacted substrate(s). Gas solubility follows the same trend, with carbon dioxide gas showing exceptional solubility in many ionic liquids, carbon monoxide being less soluble in ionic liquids than in many popular organic solvents, and hydrogen being only slightly soluble (similar to the solubility in water) and probably varying relatively little between the more popular ionic liquids. (Different analytical techniques have yielded somewhat different absolute solubility values.)
Room temperature ionic liquids
Room temperature ionic liquids consist of bulky and asymmetric organic cations such as 1-alkyl-3-methylimidazolium, 1-alkylpyridinium, N-methyl-N-alkylpyrrolidinium and ammonium ions. A wide range of anions is employed, from simple halides, which generally inflect high melting points, to inorganic anions such as tetrafluoroborate and hexafluorophosphate and to large organic anions like bis-trifluorsulfonimide, triflate or tosylate. There are also many interesting examples of uses of ionic liquids with simple non-halogenated organic anions such as formate, alkylsulfate, alkylphosphate or glycolate. As an example, the melting point of 1-butyl-3-methylimidazolium tetrafluoroborate or [bmim][BF4] with an imidazole skeleton is about -80 °C, and it is a colorless liquid with high viscosity at room temperature.
It has been pointed out that in many synthetic processes using transition metal catalyst, metal nanoparticles play an important role as the actual catalyst or as a catalyst reservoir. It also been shown that ionic liquids (ILs) are an appealing medium for the formation and stabilization of catalytically active transition metal nanoparticles. More importantly, ILs can be made that incorporate co-ordinating groups, for example, with nitrile groups on either the cation or anion (CN-IL). In various C-C coupling reactions catalyzed by palladium catalyst, it has been found the palladium nanoparticles are better stabilized in CN-IL compared to non-functionalized ionic liquids; thus enhanced catalytic activity and recyclability are realized.
Low temperature ionic liquids
Low temperature ionic liquids (below 130 kelvins) have been proposed as the fluid base for an extremely large diameter spinning liquid mirror telescope to be based on the earth's moon.Low temperature is advantageous in imaging long wave infrared light which is the form of light (extremely red-shifted) that arrives from the most distant parts of the visible universe. Such a liquid base would be covered by a thin metallic film that forms the reflective surface. A low volatility is important for use in the vacuum conditions present on the moon.
Food science
The application range of ionic liquid also extends to food science. [bmim]Cl for instance is able to completely dissolve freeze dried banana pulp and the solution with an additional 15% DMSO lends itself to Carbon-13 NMR analysis. In this way the entire banana compositional makeup of starch, sucrose, glucose, and fructose can be monitored as a function of banana ripening.
Safety
Due to their non-volatility, effectively eliminating a major pathway for environmental release and contamination, ionic liquids have been considered as having a low impact on the environment and human health, and thus recognized as solvents for green chemistry. However, this is distinct from toxicity, and it remains to be seen how 'environmentally-friendly' ILs will be regarded once widely used by industry. Research into IL aquatic toxicity has shown them to be as toxic or more so than many current solvents already in use . A review paper on this aspect has been published in 2007. Available research also shows that mortality isn't necessarily the most important metric for measuring their impacts in aquatic environments, as sub-lethal concentrations have been shown to change organisms' life histories in meaningful ways. According to these researchers balancing between zero VOC emissions, and avoiding spills into waterways (via waste ponds/streams, etc.) should become a top priority. However, with the enormous diversity of substituents available to make useful ILs, it should be possible to design them with useful physical properties and less toxic chemical properties.
With regard to the safe disposal of ionic liquids, a 2007 paper has reported the use of ultrasound to degrade solutions of imidazolium-based ionic liquids with hydrogen peroxide and acetic acid to relatively innocuous compounds.
Despite their low vapor pressure many ionic liquids have also found to be combustible and therefore require careful handling . Brief exposure (5 to 7 seconds) to a flame torch will ignite these IL's and some of them are even completely consumed by combustion.

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types of cyclodextrins. | History of cyclodextrins

Cyclodextrins (sometimes called cycloamyloses) make up a family of cyclic oligosaccharides, composed of 5 or more α-D-glucopyranoside units linked 1->4, as in amylose (a fragment of starch). The 5-membered macrocycle is not natural. Recently, the largest well-characterized cyclodextrin contains 32 1,4-anhydroglucopyranoside units, while as a poorly characterized mixture, even at least 150-membered cyclic oligosaccharides are also known. Typical cyclodextrins contain a number of glucose monomers ranging from six to eight units in a ring, creating a cone shape. thus denoting: α-cyclodextrin: six sugar ring molecule β-cyclodextrin: seven sugar ring molecule γ-cyclodextrin: eight sugar ring molecule Cyclodextrins are produced from starch by means of enzymatic conversion. Over the last few years they have found a wide range of applications in food, pharmaceutical and chemical industries as well as agriculture and environmental engineering. It is also the chief active compound found in Procter and Gamble's deodorizing product "Febreze".
Chemical structure of the three main types of cyclodextrins. // History of cyclodextrins Cyclodextrins, as they are known today, were called "cellulosine" when first described by A. Villiers in 1891. Soon after, F. Schardinger identified the three naturally occurring cyclodextrins -α, -β, and -γ. These compounds were therefore referred to as "Schardinger sugars". For 25 years, between 1911 and 1935, Pringsheim in Germany was the leading researcher in this area, demonstrating that cyclodextrins formed stable aqueous complexes with many other chemicals. By the mid 1970's, each of the natural cyclodextrins had been structurally and chemically characterized and many more complexes had been studied. Since the 1970s, extensive work has been conducted by Szejtli and others exploring encapsulation by cyclodextrins and their derivatives for industrial and pharmacologic applications. [1] Structure
γ-CD toroid structure showing spatial arrangement. Typical cyclodextrins are constituted by 6-8 glucopyranoside units, can be topologically represented as toroids with the larger and the smaller openings of the toroid exposing to the solvent secondary and primary hydroxyl groups respectively. Because of this arrangement, the interior of the toroids is not hydrophobic, but considerably less hydrophilic than the aqueous environment and thus able to host other hydrophobic molecules. On the contrary the exterior is sufficiently hydrophilic to impart cyclodextrins (or their complexes) water solubility. The formation of the inclusion compounds greatly modifies the physical and chemical properties of the guest molecule, mostly in terms of water solubility. This is the reason why cyclodextrins have attracted much interest in many fields, especially pharmaceutical applications: because inclusion compounds of cyclodextrins with hydrophobic molecules are able to penetrate body tissues, these can be used to release biologically active compounds under specific conditions. In most cases the mechanism of controlled degradation of such complexes is based on pH change of water solutions, leading to the cleavage of hydrogen or ionic bonds between the host and the guest molecules. Alternative means for the disruption of the complexes take advantage of heating or action of enzymes able to cleave α-1,4 linkages between glucose monomers. Synthesis The production of cyclodextrins is relatively simple and involves treatment of ordinary starch with a set of easily available enzymes. Commonly cyclodextrin glycosyltransferase (CGTase) is employed along with α-amylase. First starch is liquified either by heat treatment or using α-amylase, then CGTase is added for the enzymatic conversion. CGTases can synthesize all forms of cyclodextrins, thus the product of the conversion results in a mixture of the three main types of cyclic molecules, in ratios that are strictly dependent on the enzyme used: each CGTase has its own characteristic α:β:γ synthesis ratio. Purification of the three types of cyclodextrins takes advantage of the different water solubility of the molecules: β-CD which is very poorly water soluble (18.5 g/l or 16.3mM) (at 25C???) can be easily retrieved through crystallization while the more soluble α- and γ-CDs (145 and 232 g/l respectively) are usually purified by means of expensive and time consuming chromatography techniques. As an alternative a "complexing agent" can be added during the enzymatic conversion step: such agents (usually organic solvents like toluene, acetone or ethanol) form a complex with the desired cyclodextrin which subsequently precipitates. The complex formation drives the conversion of starch towards the synthesis of the precipitated cyclodextrin, thus enriching its content in the final mixture of products. The precipitated cyclodextrin is easily retrieved by centrifugation and is later separated from the complexing agent.
Uses
Crystal structure of a rotaxane with an α-cyclodextrin macrocycle.[2] Cyclodextrins are able to form host-guest complexes with hydrophobic molecules given the unique nature imparted by their structure. As a result these molecules have found a number of applications in a wide range of fields. Other than the above mentioned pharmaceutical applications for drug release, cyclodextrins can be employed in environmental protection: these molecules can effectively immobilise inside their rings toxic compounds, like trichloroethane or heavy metals, or can form complexes with stable substances, like trichlorfon (an organophosphorus insecticide) or sewage sludge, enhancing their decomposition. In the food industry cyclodextrins are employed for the preparation of cholesterol free products: the bulky and hydrophobic cholesterol molecule is easily lodged inside cyclodextrin rings that are then removed, leaving behind a "low fat" food. Other food applications further include the ability to stabilize volatile or unstable compounds and the reduction of unwanted tastes and odour. Reportedly cyclodextrins are used in alcohol powder, a powder for mixing alcoholic drinks. The strong ability of complexing fragrances can also be used for another purpose: first dry, solid cyclodextrin microparticles are exposed to a controlled contact with fumes of active compounds, then they are added to fabric or paper products. Such devices are capable of releasing fragrances during ironing or when heated by human body. Such a device commonly used is a typical 'dryer sheet'. The heat from a clothes dryer releases the fragrance into the clothing. The ability of cyclodextrins to form complexes with hydrophobic molecules has led to their usage in supramolecular chemistry. In particular they have been used to synthesize certain mechanically-interlocked molecular architectures, such as rotaxanes and catenanes, by reacting the ends of the threaded guest. Derivatives Both β-cyclodextrin and MβCD remove cholesterol from cultured cells. The methylated form MβCD was found to be more efficient than β-cyclodextrin. The water-soluble MβCD is known to form soluble inclusion complexes with cholesterol, thereby enhancing its solubility in aqueous solution. Methyl-β-cyclodextrin are employed for the preparation of cholesterol-free products: the bulky and hydrophobic cholesterol molecule is easily lodged inside cyclodextrin rings that are then removed. It is also employed to disrupt lipid rafts by removing the cholesterol from the membrane in research.

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