The Three-centre Double Bond in Diborane

The equivalent bent bonds description of the triple bond is obtained using the same arguments used before for the double bond. Three equivalent bond orbitals Bl,B2,B3 are obtained by the linear mixing ofcr. nx, ny  

Electron diffraction studies (Bartell and Carroll, 1965) show that dibor-ane B2H6 has a D2h structure like that of ethylene C2H4 (Herzberg, 1945), 

With its 16 electrons B2H6 is an electron-deficient molecule having the ground state MO electron configuration7  

The first five ionization potentials observed from UV photoelectron spectroscopy9 for the two molecules (B2H6 Lloyd and Lynaugh, 1970 C2H4 Branton et ah, 1970) are compared in Table 2.6 with the negative of the orbital energies resulting from the theoretical MO-SCF calculations 

8 In the electron configuration of both molecules we have shown the n orbital in bold. 

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