Question

Find the number of donor atoms in thionitro ligand $(NO{S^ - })$

Answer 1

Hint: we know that a ligand is a molecule or an ion or a functional group which binds to the metal of a coordination compound. Ligands are the species which can donate a pair of electrons to the metal of a coordination compound. Donor atoms of a ligand are referred to the atoms which can donate electrons to the metal.

Complete answer:
Here in the question we are given thionitro ligand. The molecule formula of thionitro ligand is $(NO{S^ - })$. It is made of nitrogen, oxygen and sulphur. All three elements are nonmetals and are electronegative in nature. Donor atoms of ligand are the atoms which can donate electrons to the metal of the coordination compound. So, in thionitro ligand all three atoms can donate electrons because they are electron rich elements. So, there are three donor atoms in the thionitro ligand.

Additional information:
We use the denticity to determine a ligand on the basis of their total donating atoms. If a ligand has one donating atom, they are said to be monodentate or bidentate ligands. If a ligand has two donating atoms they are said to bidentate ligands. Ligands with three donating atoms are known as tridentate ligands. For example, pyridine is a bidentate ligand because it has two donor atoms. Ligands with more than one donating atom is known as multidentate ligands polydentate ligands.

Note: always remember that thionitro ligand has three donor atoms. Thionitro ligand is a tridentate ligand. All the three atoms of thionitro ligand that is nitrogen, oxygen and sulphur can donate electrons.