1. In [Ti (H2O)6]2+ , the central metal ion is Ti3+ which has d1 configuration. This single electron occupies one of the t2g orbitals in the octahedral aqua ligand field.
2. When white light falls on this complex, the d electron absorbs light and promotes itself to eg level.
3. The spectral data show the absorption maximum is at 20000 mol-1 corresponding to the crystal field splitting energy (∆0) 239.7 kJ mol-1 . The transmitted colour associated with this absorption is purple and hence the complex appears in purple in colour.