Which type of bonds are present in diborane?

Diborane (B2H6) features a unique structure that includes three-center, two-electron bonds, commonly referred to as 3C-2c bonds. This type of bonding occurs when three atoms share two electrons, which allows for the formation of bonds that are characteristic of compounds with less conventional bonding scenarios.

In diborane, the boron atoms each form two terminal B-H bonds, while two hydrogen atoms are situated between the two boron atoms, thereby participating in bonding that connects all three atoms. This arrangement leads to the formation of the 3C-2c bonds where each bond involves contributions from three atoms (the two boron atoms and one hydrogen atom) sharing two electrons.

Understanding the bonding in diborane is essential, as it distinguishes the molecular geometry and the reactivity of the compound compared to those featuring standard covalent bonds that involve two atoms sharing a pair of electrons. The presence of these 3C-2c bonds is pivotal in recognizing the unique properties of diborane in the context of boron hydride chemistry.