Types of Ligands Preparation and Properties

Types of Ligands Preparation and Properties

Types of Ligands :

Ligands are classified on the basis of number of donor atoms:

Monodentate ligands or unidentate ligands

They have one donor atom ie, they supply only one electron pair to central metal atom or ion. Some unidentate ligands are given in table 9.1:

Table 9.1: Some common monodentate ligands

Name of ligand	Name	Donor atom	Charge
H2O	Aqua	O	0
NH3	Am mine	N	0
CO	Carbonyl	O	0
C5H5N or Py	Pyridine	N	0
(C6H5)3 P or Ph3P	Triphenyl phosphine	P	0
NO	Nitrosyl	N	0
X–	Halo	X	-1
OH–	Hydroxo	O	-1
CN–	Cyano	C	-1
NC–	Isocyano	N	-1 .
NO–2	Nitro	N	-1
ONO–	Nitrito	O	-1
H–	Hydrido	H	-1
NH–2	Amido	N	-1
O2-2	Peroxo	O	-1
O-2                        .	Oxo	O	-2
CO32-	Carbonato	O	-2
SO42-	Sulphato	O	-2
NH-2	Imido	N	-2
S-2	Sulphido	S	-2
N3–	Azido	N	-3
p-3	Phosphido	P	-3

Bidentate Ligands

The ligands which contain two donor atoms or ions through which they are bonded to the central ion are called bidentate ligands.

Tridentate Ligands

Ligands which have three donor atoms are called tridentate ligands.

Tetradentate Ligand

Tetradenate ligands bind with four donor atoms.

Pentadentate Ligand

Ligands which have five donor atoms are called pentadentate ligand.

Ethylenediaminetriacetato (EDTA)^-3

Hexadentate Ligand

Ligands which have six donor atoms.
Example: Ethylenediaminetetracetato

Chemistry Notes