In organic chemistry, an alkane, or paraffin, is an acyclic saturated hydrocarbon. In other words, an alkane consists of hydrogen and carbon atoms arranged in a tree structure in which all the carbon–carbon bonds are single. Alkanes have the general chemical formula CnH2n+2; the alkanes range in complexity from the simplest case of methane, where n = 1, to arbitrarily large and complex molecules, like pentacontane or 6-ethyl-2-methyl-5- octane, an isomer of tetradecane. IUPAC defines alkanes as "acyclic branched or unbranched hydrocarbons having the general formula CnH2n+2, therefore consisting of hydrogen atoms and saturated carbon atoms". However, some sources use the term to denote any saturated hydrocarbon, including those that are either monocyclic or polycyclic, despite their having a different general formula. In an alkane, each carbon atom is sp3-hybridized with 4 sigma bonds, each hydrogen atom is joined to one of the carbon atoms; the longest series of linked carbon atoms in a molecule is known as its carbon skeleton or carbon backbone.
The number of carbon atoms may be considered as the size of the alkane. One group of the higher alkanes are waxes, solids at standard ambient temperature and pressure, for which the number of carbon atoms in the carbon backbone is greater than about 17. With their repeated –CH2 units, the alkanes constitute a homologous series of organic compounds in which the members differ in molecular mass by multiples of 14.03 u. Methane is produced by methanogenic bacteria and some long-chain alkanes function as pheromones in certain animal species or as protective waxes in plants and fungi. Most alkanes do not have much biological activity, they can be viewed as molecular trees upon which can be hung the more active/reactive functional groups of biological molecules. The alkanes have two main commercial sources: natural gas. An alkyl group is an alkane-based molecular fragment, they are abbreviated with the symbol for any organyl group, R, although Alk is sometimes used to symbolize an alkyl group. Saturated hydrocarbons are hydrocarbons having only single covalent bonds between their carbons.
They can be: linear wherein the carbon atoms are joined in a snake-like structure branched wherein the carbon backbone splits off in one or more directions cyclic wherein the carbon backbone is linked so as to form a loop. According to the definition by IUPAC, the former two are alkanes, whereas the third group is called cycloalkanes. Saturated hydrocarbons can combine any of the linear and branching structures. Alkanes are the acyclic ones, corresponding to k = 0. Alkanes with more than three carbon atoms can be arranged in various different ways, forming structural isomers; the simplest isomer of an alkane is the one in which the carbon atoms are arranged in a single chain with no branches. This isomer is sometimes called the n-isomer; however the chain of carbon atoms may be branched at one or more points. The number of possible isomers increases with the number of carbon atoms. For example, for acyclic alkanes: C1: methane only C2: ethane only C3: propane only C4: 2 isomers: n-butane and isobutane C5: 3 isomers: pentane and neopentane C6: 5 isomers: hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane C12: 355 isomers C32: 27,711,253,769 isomers C60: 22,158,734,535,770,411,074,184 isomers, many of which are not stable.
Branched alkanes can be chiral. For example, 3-methylhexane and its higher homologues are chiral due to their stereogenic center at carbon atom number 3. In addition to the alkane isomers, the chain of carbon atoms may form one or more loops; such compounds are called cycloalkanes. Stereoisomers and cyclic compounds are excluded; the IUPAC nomenclature for alkanes is based on identifying hydrocarbon chains. Unbranched, saturated hydrocarbon chains are named systematically with a Greek numerical prefix denoting the number of carbons and the suffix "-ane". In 1866, August Wilhelm von Hofmann suggested systematizing nomenclature by using the whole sequence of vowels a, e, i, o and u to create suffixes -ane, -ene, -ine, -one, -une, for the hydrocarbons CnH2n+2, CnH2n, CnH2n−2, CnH2n−4, CnH2n−6. Now, the first three name hydrocarbons with single and triple bonds, it is impossible to find compounds with more than one IUPAC name. This is because shorter chains attached to longer chains are prefixes and the convention includes brackets.
Numbers in the name, referring to which carbon a group is attached to, should be as low as possible so that 1- is implied and omitted from names of organic compounds with only one side-group. Symmetric compounds will have two ways of arriving at the same name. Straight-chain alkanes are sometimes indicated by the prefix "n-" where a non-lin
John Rogers Cooke was a Virginia planter and politician who served a single term in the Virginia House of Delegates. Born in Bermuda to Stephen Cooke and his wife Catherine Esten, John Rogers Cooke would first live with his parents in Alexandria, the read law and move westward along the Potomac River, he moved to Martinsburg circa 1810. He and his wife Maria Pendleton, daughter of Col. Philip Pendleton, would have 13 children, of whom lawyers Philip Pendleton Cooke and John Esten Cooke would achieve distinction as writers, the latter becoming a Confederate soldier. During the War of 1812 he served in Berkeley County's volunteer artillery company under Capt. James Faulkner and Capt. Robert Wilson, all of whom helped defend Norfolk, Virginia as part of a battalion commanded by Major Andrew Waggoner and Col. Elisha Boyd. Cooke operated plantations using enslaved labor, the common practice was to move when the soil lost nutrients because of common farming practices of the day. Residents of Berkeley County would elect Cooke and George Newkirk as their representatives in 1814, but neither would be re-elected.
Cooke would be elected to represent the County during the Virginia Constitutional Convention of 1829-1830. For a time he lived at "Ambler's Hill," a plantation near Winchester, Virginia in Frederick County, Virginia. In 1838, "Glengary", the family estate to which the Cookes had moved, burned down; the family moved in 1840 to Richmond, Virginia. Cooke died in Richmond, Virginia in 1854, was buried at Shockoe Hill Cemetery
The Federation of German-American Clubs was founded in 1948 and consists of 27 local clubs from all over Germany. The Federation is committed to fostering cultural exchange and cooperation between the U. S. and Germany. Student- and youth exchange programs belong to their projects. In 1946, Merle A. Potter, a US-Army Captain, Prince Louis Ferdinand von Preussen founded the "Bad Kissingen Cosmopolitan Club", the first German-American club, closed again soon after the prohibition of fraternization took effect. Potter was ordered to Ansbach to work with the military government. After James F. Burch's famous "Restatement of Policy on Germany"-speech in 1946, the prohibition of fraternization was overruled under military governor Lucius D. Clay. In the following year, Clay ordered that Potter would be founding various German-American clubs in the American sector. In September 1947, Major Potter invited the newly founded German-American clubs to a first meeting in Heidelberg. Through a telegram, General Clay sent his regards to the delegates, expressing that "democracy can only grow through friendship and discussion, the military government supports the meeting of leading American and German individuals".
In June 1948 the second conference took place in Bad Kissingen. 17 clubs, including 2 women's clubs, attended. The foundation of a head organization, named "FEDERATION OF GERMAN-AMERICAN SOCIAL DISCUSSION CLUBS", was decided. At another meeting in Munich in May 1949, the organization was renamed "FEDERATION OF GERMAN-AMERICAN CLUBS"; this term is being used to the present day. In 1957, the student exchange program "A Bridge Across the Atlantic Ocean" was started, its purpose was to intensify the cultural exchange between the young generations in Germany and the United States. In 1958, another youth exchange program was introduced as a new project, giving students between the age of 14 and 18 a chance to visit Germany or the United States. In 1980, the Federation granted the "Lucius D. Clay-Medal" to John Jay McCloy; the Medal since has been awarded annually to individuals that have contributed to German-American Friendship. As of today, the Federation consists of 31 clubs and has offices in Washington, New York and San Francisco.
Since its beginnings in 1957, the student exchange has given more than 2,000 young Americans and Germans the chance to participate in academic exchange. Annually, about 25 German students go to the US. 19 American and 22 German universities participate in the Program. The VDAC Alumni e. V. gives the returnees a network and the chance to get involved after their exchange ended. Since 1958 the youth program is an essential part of the Federation's projects. For young people between the age of 14 and 18, seminars and trips, the so-called "home stay-program", are being organized; the goal is to develop a sense of tolerance through cultural exchange. The "Gazette" publishes information and news regarding the German-American clubs; the "Gazette" is the official news platform of the Federation. The German-American Day annually honors German-American relations by granting the "Lucius D. Clay-Medal" to individuals that contributed to German-American understanding. In the past, medals went to Hans-Dietrich Genscher and Thomas Reiter for example.
The following individuals are members of the honorary board of the Federation of German-American Clubs: Horst Seehofer, Prime Minister of Bavaria John B. Emerson, US-Ambassador to the Federal Republic of Germany Juergen Hardt, coordinator for transatlantic relations of the German government Georg Friedrich Prinz von Preussen Werner Weidenfeld Fred B. Irwin Official website Online-issue of the Gazette