What characteristics do you expect from an electrondeficient hydride with respect to its structure and chemical reactions?

Explanation

There is insufficient number of electrons in the valence shell of the centre atom. So, in this type of hydrides, the valence shell of the central atom does not have a complete octet configuration. For example, in `BH_(3)`, valence shell of B has six electrons and the hydrides are trigonal planar in shape.
(2) Due to electron deficiency, this type of hydrides act as lewis acids, i.e., they accept electron pairs.
For example, `H_(3) B + NH_(3) " "rarr" "H_(3)B larr: NH_(3)`
(3) To compensate the electron deficiency, the hydrides form dimers, trimers and polymers and attain stability.
For example, `B_(2)H_(6), B_(4)H_(10), (AlH_(3))_(n)` etc.
(4) Electron deficient hydrides are extremely reactive. they easily react with both metals and non-metals.