With trembling hands, I quickly drew the formula for benzene with three-electron bonds and immediately saw that the spins of the central electrons were in the opposite direction. This means that there should be a simple and understandable explanation of aromaticity and antiaromaticity, moreover, a visual one. I immediately realized that if the three-electron bond exists in oxygen, then it must exist in benzene. ![]() Once, in the summer of 1995, I clearly realized this simple fact: that the oxygen formula cannot be written if we do not accept that there is a real three-electron bond with normal multiplicity, that is, 1.5. But, this cannot be done without a three-electron bond with a multiplicity of 1.5, since the oxygen molecule has a bond order equal to 2 (this is an experimental fact, infrared spectra). Therefore, you can try to depict the structure of a molecule in the classical language of chemistry: using points (electrons), that is, Lewis formulas. ![]() But, the distribution of electron density in a molecule must be stationary and averaged over time. The MO method easily explains oxygen paramagnetism in a purely schematic manner. I graduated from university a year ago, just got a job as a teacher of organic chemistry at the university, and just got married :). The paramagnetism of oxygen literally kept me awake. I came to the idea of a three-electron bond not by studying benzene, but by working on the oxygen formula. The principle of the interaction of fermions always one, everywhere. This is also true for the electron shells in the atom and aromatic systems. Hückel rule (4n + 2) for aromatic systems can be written in a different form, in the form of 2n where n - unpaired number. Nothing prohibits to give a definition of the multiplicity of bond: the multiplicity of bond is the energy of bond expressed in dimensionless units. The existence of large aromatic monocycles has been proved impossible based on interaction of three-electron bonds through the cycle at distances between the bonds (through the cycle) greater than 3.5 Å due to the lack of energy interaction (the length of chemical bonds is in the range of distances 0.74 Å – 3.5 Å). Using these dependences it is possible to calculate chemical bound energy by different bond distance or different multiplicity of chemical bond, that makes possible to calculate delocalization energy of benzene molecule. It was shown, that functional relation y = a + b/x + c/x^2 fully describes dependence of energy and multiplicity of chemical bond on bond distance (multiplicity = f(L) and Е = f(L), where multiplicity is multiplicity of bond, L – length of bond in Å, Е – energy of bond in kj/mole, C-N, C-O, C-S, N-N, N-O, O-O, C-P). ![]() Using the concept of three-electron bond one can represent the actual electron structure of benzene, explain specificity of the aromatic bond and calculate the delocalization energy. It is a new type of chemical bonding that explains the resistance of benzene and chemical properties and other properties in aromatic compounds. In benzene formed a new type of chemical bonds - an aromatic bond (C-C), which has a multiplicity of more than 1.5 (1.66) (multiplicity C-C in ethane = 1 and multiplicity C-C in ethylene = 2). The aromatic bond is a three-electron bond in flat cyclic systems with a specific interaction of electrons through the cycle. I think that you will be interested to read my works about three-electron bond in benzene.
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