Question

Which of the following compounds is converted into the dimer form?

Solution

Correct option is

BH3

 

In all cases octet is not fulfilled for B-atom. So in monomer form all of them are Lewis acids.

In BF3 the Lewis acidity is internally compensated by ‘B–F’ π bond (back bonding) formation which is not possible for BCl3 or BBr3 due to the size dissimilarity between ‘B–Cl’ or ‘B–Br’. So BCl3 and BBr3 have the tendency to form dimer. But due to steric factor, four ‘Cl–atoms’ or ‘Br-atoms’ cannot be arranged around ‘B-atom’ and they remain as monomer. But BH3 forms B2H6 to satisfy Lewis acidity by the formation of 2-electrons-3-centred bond (banana bonding).

SIMILAR QUESTIONS

Q1

Name of the structure of silicates in which three oxygen atoms of [SiO4]4–are shared is: 

Q2

CO2 is isostructural with

Q3

Which of following is called ‘Inorganic Benzene’?

Q4

Which of the following is used as control rods in nuclear reactors?