Based on MOT, a solution of [TiCl6]3- is colored due to the electronic transition fromSelect one:t2g → eg*eg → t2g*t2g → egeg → t2g

To find the correct answer to the question regarding the electronic transitions in the complex ion $[TiCl_6]^{3-}$ based on Molecular Orbital Theory (MOT), we need to consider the electronic configuration and the nature of the d-orbitals involved.

1. Understanding the d-Orbitals

In a typical octahedral field, the d-orbitals split into two sets:

• $t_{2g}$ (lower energy)
• $e_g$ (higher energy)

2. Electronic Configuration of Titanium

Titanium in its +3 oxidation state, as in $[TiCl_6]^{3-}$, has the configuration:

• Atomic number of Titanium (Ti) = 22
• Configuration of Ti = $[Ar] 3d^2 4s^2$
• In Ti$^{3+}$, it loses three electrons: $[Ar] 3d^1$

3. Possible Electronic Transitions

The possible transitions considering d-orbitals are:

• $t_{2g} \rightarrow e_g^*$ (excited state)
• $e_g \rightarrow t_{2g}$
• $t_{2g} \rightarrow e_g$
• $e_g \rightarrow t_{2g}$

Based on the lower and higher energy levels of d-orbitals:

• When electrons in the lower energy $t_{2g}$ orbitals absorb energy, they can be excited to the higher energy $e_g$ orbitals.

4. Conclusion

The color of the complex arises from the transitions of electrons due to energy absorption leading to exciting electrons. Therefore, the correct answer is:

Final Answer

• $t_{2g} \rightarrow e_g^*$