In chemistry, delocalized electrons are electrons in a molecule, ion or solid metal that are not associated with a single atom or a covalent bond. The term delocalization is general and can have different meanings in different fields. In organic chemistry, this refers to resonance in aromatic compounds. In solid-state physics, this refers to free electrons. In quantum chemistry, this refers to molecular orbital electrons that have extended over several adjacent atoms. In the simple aromatic ring of benzene the delocalization of six π electrons over the C6 ring is graphically indicated by a circle; the fact that the six C-C bonds are equidistant is one indication that the electrons are delocalized. In valence bond theory, delocalization in benzene is represented by resonance structures. Delocalized electrons exist in the structure of solid metals. Metallic structure consists of aligned positive ions in a "sea" of delocalized electrons; this means that the electrons are free to move throughout the structure, gives rise to properties such as conductivity.
In diamond all four outer electrons of each carbon atom are'localized' between the atoms in covalent bonding. The movement of electrons is restricted and diamond does not conduct an electric current. In graphite, each carbon atom uses only 3 of its 4 outer energy level electrons in covalently bonding to three other carbon atoms in a plane; each carbon atom contributes one electron to a delocalized system of electrons, a part of the chemical bonding. The delocalized electrons are free to move throughout the plane. For this reason, graphite conducts electricity along the planes of carbon atoms, but does not conduct in a direction at right angles to the plane. Standard ab initio quantum chemistry methods lead to delocalized orbitals that, in general, extend over an entire molecule and have the symmetry of the molecule. Localized orbitals may be found as linear combinations of the delocalized orbitals, given by an appropriate unitary transformation. In the methane molecule for example, ab initio calculations show bonding character in four molecular orbitals, sharing the electrons uniformly among all five atoms.
There are two orbital levels, a bonding molecular orbital formed from the 2s orbital on carbon and triply degenerate bonding molecular orbitals from each of the 2p orbitals on carbon. The localized sp3 orbitals corresponding to each individual bond in valence bond theory can be obtained from a linear combination of the four molecular orbitals. Aromatic ring current Electride Solvated electron
Juan Carlos Báguena is a tennis coach and former professional tennis player from Spain. Báguena was a doubles player and reached the semi-finals at Bari in 1988, he made the second round of the men's doubles in the 1989 French Open. The pair beat Australians Darren Cahill and Mark Kratzmann in what was a close opening round encounter, won 9–7 in the third and final set. In the mixed doubles he played with Jo-Anne Faull and reached the second round. In 1990, Baguena teamed up with Omar Camporese to win the Madrid Trophy. At the same event he reached the singles quarter-finalist, he reached the doubles semi-finals in Genova that year. The Spaniard made his only Grand Slam singles appearance at the 1991 French Open and lost a five set opening match to Christian Miniussi, his best performance of the year came in Florence, where he and Carlos Costa were doubles runners-up. Juan Carlos Báguena at the Association of Tennis Professionals Juan Carlos Báguena at the International Tennis Federation
"Both of Us" is a song by American rapper B.o. B, released on May 22, 2012, as the third single from his second studio album, Strange Clouds; the song features vocals from American singer-songwriter Taylor Swift. The artists co-wrote the song alongside the song's producers, Dr. Luke and Cirkut. "Both of Us" was released to critical acclaim, most praising Swift's feature, with some calling the country rap collaboration as a sweet and melodic catchy song. It debuted on the Australian Singles Chart at number 46; the song sold 143,000 copies in its first week of release in the United States, debuting at number 18 on the US Billboard Hot 100 and became the week's top debut. "Both of Us" is an alternative hip hop song, with musical influences of country rap and dubstep, lyrical influences of conscious hip hop. The lyrics of "Both of Us" talks about bullying, it was Swift who came up with the idea for the collaboration after she visited B.o. B's label, Grand Hustle Records; the rapper explained, "she hit up Grand Hustle.
I wasn't there. Tip was there and I linked with her in Dallas and the rest is history." This is not the first time. I. Nicki Minaj, Flo Rida to her Speak Now World Tour in 2011; the music video, directed by Jake Nava, was released on June 27, 2012. B.o. B announced the video on Twitter, sharing a photo and a release date time frame: "On the set of the #BothOfUs music video in Nashville with @taylorswift13. Video premieres end of June!". The video begins with B.o. B standing before a small American flag cuts to Swift singing the song's hook in a dark lit pool hall. B.o. B takes to the train tracks and streets to deliver his verses while Swift croons the hook in a picturesque field while donning a white cotton dress, shows a dog that leaves Swift awestruck with his high flying antics. Footage of the artists is interspliced with scenes of life in Nashville's less glamorous neighborhoods like tatted locals, cowboy-boot-wearing young women, shirtless youths playing in sprinklers, teens kissing, a mobile home.
As the first chorus precedes Swift is shown singing at a field covered with dandelions and flowers and several shots of B.o. B and Swift are interspliced; as the video closes out, viewers are left with B.o.. B and Swift re-imagined as the every man and every woman living simple life in rural Tennessee, much like the folks in the video. At the end, we see B.o. B standing in a driveway with a car backing up and B.o. B staring at it; as of January 2020 the video has over 55 million views on YouTube. The song was successful in Australia and New Zealand, charting within the top ten in both Australia and New Zealand, it debuted on the Australian Singles Chart at number 46 and peaked at number five. The song peaked at number ten in New Zealand; the song sold 143,000 copies in its first week, along with the album release, debuting at number 18 on the US Billboard Hot 100 and became the week's top debut. The single sold over 1,000,000 digital copies as of November 2017. Swift performed the song with B.o. B on April 19, 2013 in the State Farm Arena in Atlanta when the rapper was invited as a surprise guest for the show for Swift's Red Tour