Orbital structure of Diborane :
Diborane has less number of electrons than required for the formation of normal bonds between the atoms. Thus, diborane is an Electron deficient molecule.
Diborane formula is . It is a colourless gas.
Diborane structure :
In diborane, each Boron atom provides three electrons and each hydrogen atom provides one electron for bonding. It has 12 valency electrons in total which can form six bonds only.
In diborane each boron atom in an excited state undergoes hybridization resulting in the formation of four – hybrid orbitals. Three of them has a single electron each and the fourth one is vacant. At each boron atom two hybrid orbitals with single electron are overlapped by the s – orbital of H – atom forming two B – H covalent bonds. Thus in the molecule of diborane, there are four B – H covalent bonds which are planar (Terminal).