1.1Supramolecular chemistry:
Supramolecular chemistry is interdisciplinary branch of science encompassing chemical, physical and biological facets of chemical species of higher complexity glued, organized and structured by means of weak intermolecular (non-covalent) interactions [103]. Traditional or molecular chemistry deals with the covalent bond (atoms and bond between atoms), whereas supramolecular chemistry pivots around molecules and the bond between molecules. Intermolecular interactions constitute the heart of supramolecular chemistry. According to Lehn supramolecular chemistry is “chemistry beyond the molecule” i.e to examine the weaker and reversible non-covalent interactions between molecules [104].
In recent years, supramolecular
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Anisic acid and its derivatives are of industrial and biological importance as they are used in chemical reaction (as intermediate) to obtain target materials such as dyes pharmaceuticals, perfumes, photo-initiators and agrochemicals. Phenylalkonic acids (Naproxen) exhibit anti-inflammatory, analgesic and antipyretic properties and used in the treatment of rheumatoid, arthritis and spondilytus [73] whereas, phenyoxyalkanoic acids are used in the synthesis of a family of ester derivatives, fermentation of Penicillin V, synthesis of insect repellents, esters of cortical hormones and cation exchange resins. Besides this its analogous substituted phenoxy acetic acid are known to be common commercial auxin herbicides …show more content…
Since ages Copper the ‘cornerstone’ of human civilization has been harnessed by man because of its usefulness. In Greece, copper was known by the name chalkos whereas in Roman times, it was well-known as aes Cyprium, aes being the generic Latin term for copper alloys and Cyprium (metal of Cyprus) named after the place from where it was excavated. The phrase was simplified to cuprum, which was later coined to copper. In prehistoric times the seven heavenly bodies were linked with the seven metals, i.e. Sun-Gold (Au). Moon-Silver (Ag), Mercury-Mercury (Hg), Mars-Iron (Fe), Jupiter-Tin (Sn), Saturn-lead (Pb) and Venus was assigned to copper (Cu). In history the transition period between the Neolithic and the Bronze Age was formerly known as the Chalcolithic period. During medieval (mythology and alchemy) period copper because of its lustrous splendor, was used in manufacturing
Discussion and Conclusions: Interpreting these results have concluded that relative reactivity of these three anilines in order of most reactive to least reactive go; Aniline > Anisole > Acetanilide. Aniline, has an NH2 , the most active substituent , and adds to any ortho/para position available on the ring. This data is confirmed with the product obtained, (2,4,6 tribromoaniline, mp of 108-110 C). As for anisole, it has a strongly activating group attached, OMe an alkoxy group, and it added in two of the three available spots, both ortho. The results conclude: (2,4-Dibromoanisol mp 55-58 C ). Acetanilide has a strong activating group attached, acylamino group, but this group is large and the ortho positions are somewhat hindered so the majority of the product obtained added at the para position, results conclude: (p-bromoacetanilide mp 160-165 C). Since all the substituents attached to the aromatic rings were activators the only products able to be obtained were ortho/para products.
Although some of the elements have been known for thousands of years, our understanding of many elements is still young. Mendeleev’s first Periodic Table contained only 63 elements, and about that many were discovered in the following 100 years. Just like countries, emperors, philosophers, and cities, elements have histories, too.“The Disappearing spoon” by Sam Kean, is a detailed history of the elements on the Periodic Table. Kean does a important job of telling every single element’s journey throughout the history of mankind: from the earliest times, when chemistry was intermingled with alchemy, to these days of modern chemistry. For example: Thallium is considered the deadliest element, pretending to be potassium to gain entry into our cells where it then breaks amino acid bonds within proteins. The CIA once developed a plan to poison Fidel Castro by dosing his socks with thallium-tainted
Innovated by the fact that ancient people use willow bark to ease pain, the first chemically pure and stable acetylsalicylic acid was synthesized by a German chemist called Felix Hoffmann, in 1897 (Bayer AG, 2011). Aspirin was firstly taken by his father in order to reduce his arthritis pain. Aspirin successfully eased the pain. After two years’ laboratory experiment, aspirin as a product was first launched by Bayer AG in 1899 (Bayer AG, 2011). The coming world war accidentally boosted the demand of aspirin.
Arsenic has been one of the elements most mentioned during the middle and even modern age. It was formerly known by Chinese, Romans, Greeks and even earlier, by the Babylonians. The Greeks used the arsenic oxide (III) as a depilatory, and 4,000 years before the Christian era, arsenic was involved in the development of early bronzes. However, the arsenic was released in early civilizations through compounds or substances containing the element, which by its color and appearance would favor the conversion of base metals into gold. It was also used by the alchemists in the method of making the pill of immortality. In the philosophy of alchemy, arsenic represents the masculine principle. The masculinity of arsenic was different, because it combined with an element that was considered as masculine such as sulfur, forming orpiment and realgar.
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To examine the interaction between two molecules in solution without isolating the compound Jobfs method is used. Although unstable compounds tend to be generated, this is not a reflection of weak interactions. In some cases, the transition metal species cannot be crystallized from the solution and separated from the other species present. Without Jobfs Method this composition can be very difficult to deduce.
This essay has therefore discussed the most popular classes of plant chemical defences, namely terpenes, phenolics, nitrogen-based defences and allelopathy. The effects of these defences on herbivores has also been touched on. Many of these compounds produced by plants have later been extracted by humans for use as insecticides. Compounds such as tannins are also used in the wine industry. These chemicals thus have a very strong economic influence.
Thickett, Geoffrey. Chemistry 2: HSC course. N/A ed. Vol. 1. Milton: John Wiley & Sons Australia, 2006. 94-108. 1 vols. Print.
David and John Free. (26 Nov 2006). MadSci Network: Chemistry. Retrieved on March 6, 2011, from http://www.madsci.org/posts/archives/2007-02/1171045656.Ch.r.html
The writings of some Greek philosophers may be considered to be among the very first chemical theories, such as the theory that all things are composed of air, earth, fire, and water. Each of these were represented by different elements, such as sulfur, salt, mercury, and, ideally, gold. Other ideas held by alchemists were that each of the known elements were represented by heavenly bodies. Gold was earth's representation of the sun, silver for the moon, mercury for the planet Mercury, copper for Venus, iron for Mars, tin for Jupiter, and lead for Saturn.
V. Amarnath, D. C. Anthony, K. Amarnath, W. M. Valentine, L. A. Wetterau, D. G. J. Org. Chem. 1991, 56, p. 6924-6931.
The first known source of silver is believed to be the mines around Anatolia, now known as Turkey, in 4000 BC. This supplied the flourishing cultures around Greece, Crete, and the Near East. Around 2500 BC the Chaldeyans developed a process called “cupellation” to extract silver from silver-lead ores. During the rise and fall of civilizations around Europe and Asia Minor, silver value remains high, with major silver sources moving from Laurium (near Athens, and produced the largest amount of silver during this era), Asia Minor, Sardinia, Asia, Spain, Germany, and Austria-Hungary.
There has been much excitement about the latest science news in which a remote controlled airplane was flown using seawater fuel. The U.S. Navy created the fuel by taking carbon dioxide and hydrogen from seawater and combing them to create an organic compound called a hydrocarbon, which can be used for energy. I believe this is a really an amazing discovery since the earth has a lot of seawater to use as fuel. The oil, gas and coal we currently use as fuel will not last forever. The possible use of seawater as future source of fuel is just one of many applications of organic compounds, compounds which contain carbon molecules. Carbon is a unique element because it has the ability to form many compounds with itself and with other nonmetal elements like oxygen, hydrogen, nitrogen, sulfur and phosphorous. Carbon has four electrons on its outer shell, which leaves four electrons available to create covalent bonds with other carbon molecules and other various elements. Carbon’s unique properties include forming single, double and triple bonds which can combine with other atoms, forming chains which can combine with other elements and forming isomers, which are molecules that have similar composition as the original molecule but a different arrangement of its atoms. Organic compounds, which have been found naturally or have been made synthetically by chemists, make our life much easier. Some of the many applications of organic chemistry are in medicine, energy sources and industry.
The development of quantum mechanics in the 1920's and 1930's has revolutionized our understanding of the chemical bond. It has allowed chemists to advance from the simple picture that covalent and ionic bonding affords to a more complex model based on molecular orbital theory.
Metals are currently in high demand by society. A high percentage of common everyday items you use and see utilises a form of metal. That wooden table in a common kitchen that looks like it is made completely of wood. Metals are still used in that "completely wooden table" as the screws used to hold it together are made of metals. Many commonly used metals such as iron, aluminium, and/or copper are all found from ores. An ore is a mixture in the form of a rock that is mined. For example, bauxite is an ore that contains a high percentage of pure aluminium. That pure aluminium is then extracted, refined, and crafted in to many everyday items such as cars, foil, and ladders. Chemists are continuously researching an innovative approach to extract and refine pure metals from ores while using fewer amounts of energy. Society's requirement of metals is increasing by the year as science and technology advances.