Search results
Results from the WOW.Com Content Network
Benzene, the most widely recognized aromatic compound with six delocalized π-electrons (4n + 2, for n = 1).. In organic chemistry, Hückel's rule predicts that a planar ring molecule will have aromatic properties if it has 4n + 2 π-electrons, where n is a non-negative integer.
In the simple aromatic ring of benzene, the delocalization of six π electrons over the C 6 ring is often graphically indicated by a circle. The fact that the six C-C bonds are equidistant is one indication that the electrons are delocalized; if the structure were to have isolated double bonds alternating with discrete single bonds, the bond would likewise have alternating longer and shorter ...
Benzene and cyclohexane have a similar structure, only the ring of delocalized electrons and the loss of one hydrogen per carbon distinguishes it from cyclohexane. The molecule is planar. [ 58 ] The molecular orbital description involves the formation of three delocalized π orbitals spanning all six carbon atoms, while the valence bond ...
The theory predicts the molecular orbitals for π-electrons in π-delocalized molecules, such as ethylene, benzene, butadiene, and pyridine. [ 1 ] [ 2 ] [ 3 ] It provides the theoretical basis for Hückel's rule that cyclic, planar molecules or ions with 4 n + 2 {\displaystyle 4n+2} π-electrons are aromatic .
However, in benzene the remaining six bonding electrons are located in three π (pi) molecular bonding orbitals that are delocalized around the ring. Two of these electrons are in an MO that has equal orbital contributions from all six atoms. The other four electrons are in orbitals with vertical nodes at right angles to each other.
Whereas benzene is aromatic (6 electrons, from 3 double bonds), cyclobutadiene is not, since the number of π delocalized electrons is 4, which of course is a multiple of 4. The cyclobutadienide (2−) ion, however, is aromatic (6 electrons).
About 40% of people globally experience what are known as "tension headaches" and about 10% suffer from migraines, the same source noted. There are more than 150 different types of headaches, ...
For example, in benzene, the MO model gives us 6 π MOs which are combinations of the 2p z AOs on each of the 6 C atoms. Thus, each π MO is delocalized over the whole benzene molecule and any electron occupying an MO will be delocalized over the whole molecule. This MO interpretation has inspired the picture of the benzene ring as a hexagon ...