A ligand may contain one or more unshared pairs of electrons which are called the donor sites of ligands. Now, depending on the number of these donor sites, ligands can be classified as follows:
(a) Unidentate ligands: Ligands with only one donor sites are called unidentate ligands. For e.g.,\(\ddot{N}H_3\) , \(Cl^{ -}\) etc.
(b) Didentate ligands: Ligands that have two donor sites are called didentate ligands. For e.g.,
(a) \(Ethane-1,2-diamine \)
(b)\( Oxalate\space ion\)
(c) Ambidentate ligands: Ligands that can attach themselves to the central metal atom through two different atoms are called ambidentate ligands. For example
(a)
(The donor atom is N)
(The donor atom is oxygen)
(b)
Thiocyanate
(The donor atom is S) ⇢
Isothiocyanate
(The donor atom is N)
The Crystal Field Theory (CFT) of coordination compounds is based on the effect of different crystal fields (provided by the ligands taken as point charges) on the degeneracy of d-orbital energies of the central metal atom/ion. The splitting of the d-orbitals provides different electronic arrangements in strong and weak crystal fields. In tetrahedral coordination entity formation, the d-orbital splitting is smaller as compared to the octahedral entity.
What is crystal field splitting energy?
The Crystal Field Theory (CFT) of coordination compounds is based on the effect of different crystal fields (provided by the ligands taken as point charges) on the degeneracy of d-orbital energies of the central metal atom/ion. The splitting of the d-orbitals provides different electronic arrangements in strong and weak crystal fields. In tetrahedral coordination entity formation, the d-orbital splitting is smaller as compared to the octahedral entity.
On the basis of CFT, explain why [Ti(H$_2$O)$_6$]Cl$_3$ complex is coloured? What happens on heating the complex [Ti(H$_2$O)$_6$]Cl$_3$? Give reason.