a) Give the electronic configuration of the d-orbitals of `Ti` in `[Ti(H_(2)O)_(6)]^(3+)` ion in the octahedral crystal field.
b) Why is this complex coloured. Explain on the basis of distribution of electrons in d-orbitals.

Explanation

a) In the octahedral complex, `Ti` is in `+3` oxidation state and has `(t_(2g))^1(e_(g))^(0)` configuration of `Ti^(3+)` ion.
b) The unpaired `3d`-electrons is present in the `t_(2g)` level in the ground state. The next higher energy level available is `e_(g)`. Thus, there is d-d transition from `t_(2g)` to `e_(g)` `(t_(2g))^1(e_(g))^(0) to(t_(2g))^0(e_(g))^(1)`. This is responsible for the colour of the complex.