Molecular Orbital Diagram MO Electron Configuration B2 Lewis Structure: Para Or Diamagnetic Comment On Differences Or Similarities In The Bond Order And The Lewis Structure Drawn Bond Order (Show Calculation) Should This Molecule Exist? Yes Or No
The Correct Answer and Explanation is :
It seems that I’m unable to access the link you provided. However, I can still explain how to solve the problem regarding the molecular orbital diagram and bonding in the molecule ( B_2 ) (diboron), along with the concepts of bond order, paramagnetism, and diamagnetism.
1. Molecular Orbital Diagram and Electron Configuration of ( B_2 ):
In ( B_2 ), each boron atom has 5 electrons. Therefore, the molecule has a total of 10 electrons. The molecular orbitals (MO) for a diatomic molecule like ( B_2 ) can be derived from the atomic orbitals (AO) of each boron atom. The molecular orbitals are filled in the order of increasing energy:
- ( \sigma_{1s} ), ( \sigma^*_{1s} )
- ( \sigma_{2s} ), ( \sigma^*_{2s} )
- ( \sigma_{2p_z} ), ( \pi_{2p_x}, \pi_{2p_y} ), ( \pi^{2p_x}, \pi^{2p_y} ), ( \sigma^*_{2p_z} )
The energy levels for the ( B_2 ) molecule differ slightly from those of molecules like oxygen or nitrogen. For ( B_2 ), the ( \pi_{2p} ) orbitals are lower in energy than ( \sigma_{2p_z} ) due to the relative importance of the ( p )-orbitals.
2. Electron Configuration:
The electron configuration for the ( B_2 ) molecule, considering the above molecular orbitals, will be:
- ( 1\sigma_g^2, 1\sigma_u^2, 2\sigma_g^2, 2\sigma_u^2, 2\pi_g^4 ) (in the ( \pi_{2p} ) orbitals)
3. Bond Order Calculation:
Bond order is calculated using the formula:
[
\text{Bond Order} = \frac{1}{2} \left( \text{(number of electrons in bonding orbitals)} – \text{(number of electrons in antibonding orbitals)} \right)
]
In the case of ( B_2 ):
- Bonding electrons: ( 8 ) (from ( \sigma_{2s} ), ( \pi_{2p} ), and ( \sigma_{2p_z} ))
- Antibonding electrons: ( 2 ) (from ( \sigma^*_{2s} ))
[
\text{Bond Order} = \frac{1}{2} (8 – 2) = 3
]
4. Magnetic Properties:
The presence of unpaired electrons in the ( \pi^*_{2p} ) orbitals means that ( B_2 ) is paramagnetic, not diamagnetic. Paramagnetic molecules have unpaired electrons, while diamagnetic molecules have all electrons paired.
5. Existence of the Molecule:
Given that the bond order is positive, ( B_2 ) should exist. However, because of the paramagnetic nature of the molecule, it would exhibit magnetic properties and would be more reactive than other molecules with a higher bond order.
Conclusion:
- Bond Order: 3
- Magnetic Properties: Paramagnetic
- Existence: Yes, ( B_2 ) can exist.