Given below are the statements about diborane. (a) Diborane is prepared by the oxidation of $\mathrm{NaBH}_{4}$ with $\mathrm{I}_{2}$. (b) Each boron atom is in $\mathrm{sp}^{2}$ hybridized state. (c) Diborane has one bridged 3 centre-2-electron bond. (d) Diborane is a planar molecule. The option with correct statement(s) is:

JEE Main · 2021 · 22 Jul 2021 · Shift 2 · p-Block Elements

Given below are the statements about diborane.
(a) Diborane is prepared by the oxidation of

NaBH_{4}

with

I_{2}

.
(b) Each boron atom is in

sp^{2}

hybridized state.
(c) Diborane has one bridged 3 centre-2-electron bond.
(d) Diborane is a planar molecule.

The option with correct statement(s) is:

(A)(a) only✓ Correct
(B)(c) only
(C)(a) and (b) only
(D)(c) and (d) only

Answer: (A)

Solution

Diborane is obtained by oxidising sodium borohydride with iodine,

2 NaB H_{4} + I_{2} \to B_{2} H_{6} + 2 NaI + H_{2}

, so that preparation is correctly stated. Each boron uses four orbitals, two towards terminal hydrogens and two towards the bridges, so it is

s p^{3}

hybridised and not

s p^{2}

. The electron deficient molecule is held together by two bridging three centre two electron bonds, not one. The two borons and the four terminal hydrogens lie in a plane while the two bridging hydrogens lie above and below it, so the molecule is not planar. The only correct statement is the preparation of diborane by oxidation of

NaB H_{4}

with

I_{2}

JEE Main · 2021 · 22 Jul 2021 · Shift 2 · Single correct option

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JEE Main · 2021 · 22 Jul 2021 · Shift 2 · p-Block Elements

Solution

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