The structure is also illustrated as a circle around the inside of the ring to show six electrons floating around in delocalized molecular orbitals the size of the ring itself. This also represents the equivalent nature of the six carbon-carbon bonds each equivalent to ~1.5. The electrons are visualized as floating above and below the ring with the electromagnetic fields they generate acting to keep the ring flat.
General properties:
The circle symbol for aromaticity was introduced by Sir Robert Robinson and his student James Armit in 1925 and popularized starting in 1959 by the Morrison & Boyd textbook on organic chemistry. The proper use of the symbol is debated; it is used to describe any cyclic pi system in some publications, or only those pi systems that obey Hückel's rule on others.
A reaction that forms an arene compound from an unsaturated or partially unsaturated cyclic precursor is simply called an aromatization. Many laboratory methods exist for the organic synthesis of arenes from non-arene precursors.
Aromatic compounds play key roles in the biochemistry of all living things. The four aromatic amino acids histidine, phenylalanine, tryptophan, and tyrosine each serve as one of the 20 basic building blocks of proteins. Further, all 5 nucleotides (adenine, thymine, cytosine, guanine, and uracil) that make up the sequence of the genetic code in DNA and RNA are aromatic purines or pyrimidines. As well as that, the molecule heme contains an aromatic system with 22 π electrons. Chlorophyll also has a similar aromatic system.
Aromatic compounds are important in industry. Key aromatic hydrocarbons of commercial interest are benzene, toluene, "ortho"-xylene and "para"-xylene. About 35 million tonnes are produced worldwide every year. They are extracted from complex mixtures obtained by the refining of oil or by distillation of coal tar. They are used to produce a range of important chemicals and polymers, including styrene, phenol, aniline, polyester and nylon.
Almost all aromatic compounds are compounds of carbon, but they need not be hydrocarbons.
In heterocyclic aromatics one or more of the atoms in the aromatic ring is of an element other than carbon. Examples include pyridine, pyrazine, imidazole, pyrazole, oxazole, and thiophene.
Polycyclic aromatic hydrocarbons are molecules with two or more simple aromatic rings fused together by sharing two neighboring carbon atoms. Examples are naphthalene, anthracene and phenanthrene.
Many chemical compounds are aromatic rings with other things attached. Examples include trinitrotoluene (TNT), acetylsalicylic acid (aspirin), paracetamol, and the nucleotides of DNA.
Erich Probst
Erich Probst (5 December 1927 – 16 March 1988) was an Austrian footballer.He played as striker for different teams in Vienna and also abroad.
He started with Admira Wien being only 17 years old. After a year with Vienna he signed with SK Rapid Wien. In this time he won the Austrian Championship four times. In his first season with Rapid he scored 28 goals in 23 matches. Although he was always a top scorer he never shot the highest number of goals in the league.
After his time with Rapid he went to Wuppertaler SV in Germany. After the relegation of Wuppertal he went on to Switzerland playing for FC Zürich. In winter 1959 he came back to Austria to SV Austria Salzburg. The club paid 90 000 Austrian schillings, which was the highest till this time. He shot 15 goals and the team could stay in the top league. During his time with Salzburg he played his last match in the national football team. He was the first player of SV Austria Salzburg who ever played for the team.
In the 1960/61 season he was coach of SV Austria but not successful. So he went on to play as striker again. His last clubs were the SAK 1914 in Salzburg and First Vienna FC in Vienna. At all he scored 150 goals in Austrias top league.
He played 19 times for the Austrian national football team and scored 17 goals. His first match was on 27 May 1951 (4:0 versus Scotland) In the qualification match for the FIFA World Cup 1954 versus Portugal he scored 5 goals for the 9:1 win. He was member of the 1954 FIFA World Cup squad which reached the third place. During the tournament he scored six goals and was together with Max Morlock of Germany and Josef Hügi of Switzerland second in the scorer list. During his time abroad he was not player of the team. But in 1960 he played his last match versus France (2:4) where he also scored his last goal for the team. So he was the first national football team player coming from SV Austria Salzburg.
Mac Miller
Malcolm James McCormick (January 19, 1992 – September 7, 2018), known professionally as Mac Miller, was an American rapper, singer, songwriter, and record producer. He was also a noted under the pseudonym Larry Fisherman.
In early 2010, Miller signed a record deal with Pittsburgh-based indie record label Rostrum Records. He subsequently began recording his debut studio album "Blue Slide Park", and released it on November 8, 2011. The album went on to debut at number one on the U.S. "Billboard" 200 chart, making it the first independently distributed debut album to top the chart since Tha Dogg Pound's 1995 album, "Dogg Food".
In early 2013, Miller launched REMember Music, his own record label imprint, named after a friend who died. Miller's second album, "Watching Movies with the Sound Off", was released on June 18, 2013. In January 2014, Miller announced he was no longer signed to Rostrum Records. In October 2014, it was reported Miller signed a record deal for him and his label REMember, with Warner Bros. Records.
Miller died of an accidental drug overdose on September 7, 2018 at the age of 26. The cause of death was because Miller had mixed Fentanyl with Cocaine.
Crossfade (band)
Crossfade is an American rock band from Columbia, South Carolina. Crossfade has three members in the band; the current band members are Ed Sloan, Les Hall, and Mitch James. Their best known song is "Cold" which was released on May 25, 2004 and reached #2 on Billboard's Alternative Songs chart and #3 on the Billboard Mainstream Rock Tracks.
So far as of 2011, Crossfade has released 3 studio albums:
Yabasic
Yabasic (Yet Another BASIC) is an interpreter program for a version of BASIC. BASIC is a programming language. BASIC was designed by John George Kemeny and Thomas Kurtz, in 1964. However, Yabasic was born in 1995, 32 years later. Pedro Sá and Thomas Larsen are now developing version 3 of Yabasic. Yasbic is very compact at about 250 kilobytes total length.
To write something on the monitor, like Hello World, type print then <nowiki>"YOUR TEXT HERE".</nowiki>
Study this bit of code:
The result of this code is:
An audible beep is generated
The program waits for 1 second before going onto the next instruction
It then goes back to the start of the program creating an infinite loop.
This programming language can also be used to create rather complex programs such as one that calculates prime numbers
The "input" command asks the user to input a value which in this case is number that tells the program what number to stop finding prime numbers at.
The
commands create a loop that can be repeated infinitely.
The
commands hold instructions as to what the program is to do while in the loop.
The
commands tell the program to look for something and if the thing it is looking for is there then it reports back that it is there.
Shaun Marsh
Shaun Edward Marsh (born 9 July, 1983 in Narrogin, Western Australia) is an Australian cricketer. He is nicknamed 'Sos'. He is a left-handed batsman with a first-class batting average of 40.
On 8 September, 2011, Marsh made his Test debut for Australia in the 2nd Test against Sri Lanka at Pallekele in replace of the unavailable Ricky Ponting. Thus far in the Australian innings, Marsh has scored 87* batting with Michael Hussey in a 148 run partnership.
Isolobal principle