Download Bidentate & multidentate ligands File

Bidentate & Multidentate
Ligands
-Explain and use the term bidentate ligand
- Describe stereoisomerism in transition
element multidentate complexes (cis-trans &
optical isomerism)
Bidentate Ligands – Able to donate two lone
pairs to central metal ion
Ethane 1,2 diamine
(shortened to ‘en’)
NH2CH2CH2NH2
Octahedral shape
[Ni(en)3]2+
3 x bidentate
ligands...each able to
form 2 x coordinate
bonds...
coordination number =
6
Cis & Trans Isomers
[Cr(C2O4)2(H2O) 2]-
Hexadentate Ligand - EDTA
6 lone pairs to use to form
coordinate bonds
Optical Isomers:- non-superimposable mirror images
Requirements:
•
•
•
3 x bidentate ligands
2 x bidentate + 2 x
monodentate ligands
1 x hexadentate ligand
Summary Question
• Iron (III) can form the complex ion [Fe(C2O4)3]3with three ethanedioate ions. The ethanedioate
ion is a bidentate
a) Explain the term “bidentate ligand”.
b) What is the coordination number of the [Fe(C2O4)3]3complex.
c) Use your answer to part (b) to suggest what shape
the [Fe(C2O4)3]3- complex is and draw it.