Structure of diborane

5 years ago

Share

Answers : (1)

                                        












Structure of diborane


In view of the trivalency of boron, we would expect it to from a simple hydride, BH3. However, H3 is not known. This is due to the fact that hydrogen atom in BH3 has no electron to from p?- p? back bonding. Thus back boron possesses incomplete octet and HN3 is dimerised to form B2H6 molecule with covalent and three centre bond. The simplest boron hydride is diborane, B2H6.


Electrons are required for the formation of conventional covalent bond structure whereas in diborane, three are only 12 valence electrons, three from each boron atoms. Thus B2H6 is an electron drficient compound. The geometry of B2H6 can therefore be explained as follows.


The four terminal hydrogen atoms and two boron atoms lie in one plane. Above and below this plane, there are two bridging hydrogen atoms. Each boron atom forms four bonds even though it has only three electrons. The terminal B-H bonds are regular bonds but the bridge B-H bonds are different. Each bridge hydrogen is bonded to the two boron atoms only by sharing of two electrons. Such covalent bond is called three centre electron pair bond or a multi centre bond or banana bond.


The positive charge on the two H nuclei suffers strong electrostatic repulsion due to close proximity of the bridged H atoms. In order to minimize this repulsion, the orbitals of bridged H atoms are bent away from each other in the middle.

5 years ago

Post Your Answer

More Questions On Inorganic Chemistry

Ask Experts

Have any Question? Ask Experts
Post Question
 
Answer ‘n’ Earn
Attractive Gift
Vouchers
To Win!!!
Click Here for details
silver metal crystalline with a face centred cubic lattice the lenght of unit cell in found tobethe value 4.077x10 -8 m.ca;culate the atomic radius and density of silver {atomic mass of...
 
 
“silver metal crystalline with a face centred cubic lattice the lenght of unit cell in found tobethe value 4.077x10-8m.ca;culate the atomic radius and density of silver {atomic mass of...
  img
Sunil Kumar FP one month ago
 
we have density of the fcc=z*M/a^3*Na z=no of atom fro fcc it is 4 M= molecular mass Na=avagadro number a=edge length for face centered cubic unit cell=sqrt2...
  img
Sunil Kumar FP one month ago
In actinides why neodymium possess high paramagnetism than other others?
 
 
ThetetragonalNd2Fe14B crystal structure has exceptionally high uniaxialmagnetocrystalline anisotropy(HA~7teslas- magnetic field strength H in A/m versus magnetic moment in A.m2).This gives...
  img
Sunil Kumar FP 3 months ago
What is the co-ordination number of Ni in Ni(CO) 4 ?
 
 
Ni(CO)4 is an complex compound having Ni as central atom and CO as ligands.According to Werner’s theory-complex compounds show two types of valencies- 1.Primary and 2.Secondary....
  img
Aarti Gupta one month ago
Why vapour pressure does not depend on surface area?
 
 
Hello student Vapour pressure does not depend upon the surface area bacause vapours produced from the surface increases on increasing the surface area. Therefore the ratio of numbers of...
  img
Anjali Ahuja 13 days ago
 
If we prepare a solution i.e., we dissolve small amount of solute in excess of solvent. We see that on the surface of the liquid of solution, number of solvent molecules became less bacause...
  img
Raheema Javed 13 days ago
what is the best way to remember reaction mechanisms?
 
 
In order to remember reaction mechanisms,first focus on how the reaction is taking place?What is adding and what gets removed during the reaction.This will simplify to remember the...
  img
Aarti Gupta 27 days ago
what is more stable benzylic or allyic ?
 
 
An allylic cation is a carbocation with the positive charge on an allylic carbon; an allylic carbon is a carbon adjacent to an sp2 carbon of an alkene. CH2=CHC + HR ALLYLIC CARBON A benzylic...
  img
Aarti Gupta 2 months ago
View all Questions »