Diborane is a Lewis acid forming addition compound ${\mathrm{B}}_2{\mathrm{H}}_6.2{\mathrm{NH}}_3 \mathrm{with} {\mathrm{NH}}_3,$a Lewis base. This

At low temperature, an addition product,

$$\begin{gathered} {\mathrm{B}}_2{\mathrm{H}}_6.2{\mathrm{NH}}_3 \mathrm{exists} \mathrm{as} {\left[{\mathrm{BH}}_2{\left({\mathrm{NH}}_3\right)}_2\right]}^{+} \mathrm{and} {\left[{\mathrm{BH}}_4\right]}^{-} \mathrm{ions} \\ 3 {\mathrm{B}}_2{\mathrm{H}}_6.2{\mathrm{NH}}_3 \stackrel{{200}^0\mathrm{C}}{\to } \underset{\mathrm{Borazole}}{2{\mathrm{B}}_3{\mathrm{N}}_3{\mathrm{H}}_6} + 12{\mathrm{H}}_2 \uparrow \\ (\mathrm{Inorganic} \mathrm{benzene}) \end{gathered}$$