Question

Which of the following is correct related to the colours of TiCl$_3$ (X) and [Ti(H$_2$O)$_6$]Cl$_3$ (Y)?

• A. X = Colourless,\ Y = Coloured
• B. X = Coloured,\ Y = Coloured
• C. X = Colourless,\ Y = Colourless
• D. X = Coloured,\ Y = Colourless

Hint:

The presence of ligands in transition metal complexes enables d-d transitions responsible for colour.

Answer 1

The Correct Option is A

TiCl$_3$ is a solid ionic compound with Ti$^{3+}$ in an anhydrous environment and tends to be less coloured or colourless due to minimal ligand field splitting. In [Ti(H$_2$O)$_6$]$^{3+}$, water molecules create a ligand field around the Ti$^{3+}$, which undergoes d-d transitions, imparting colour.