The Conditions for Formation of a Stable Three-Electron Bond

The Conditions for Formation of a Stable Three-Electron Bond.— Let us consider the normal state of a system of three electrons and two nuclei or kernels, A and B, each with one stable bond orbital. There are only two essentially different ways of introducing the three electrons into the two available orbitals, I and j T  

The exclusion principle permits only two electrons, which must have opposed spins, to occupy either one of the orbitals the third electron must occupy the other orbital.6 

4 Notice the close similarity of this argument to that given for the one-electron bond in Sec. 1-4. 

It may be pointed out that the one-electron bond, the electron-pair bond, and the three-electron bond use one stable bond orbital of each of two atoms, and one, two, and three electrons, respectively. 

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