1. Bidentate & Multidentate Ligands Explain and use the term bidentate ligand Describe stereoisomerism in transition element multidentate complexes (cis-trans & optical isomerism)

2. 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

3. Cis & Trans Isomers [Cr(C2O4)2(H2O) 2]-

4. Hexadentate Ligand - EDTA 6 lone pairs to use to form coordinate bonds

5. Optical Isomers:- non-superimposable mirror images • Requirements: • 3 x bidentate ligands • 2 x bidentate + 2 x monodentate ligands • 1 x hexadentate ligand

6. Summary Question • Iron (III) can form the complex ion [Fe(C2O4)3]3- with three ethanedioate ions. The ethanedioate ion is a bidentate • Explain the term “bidentate ligand”. • What is the coordination number of the [Fe(C2O4)3]3- complex. • Use your answer to part (b) to suggest what shape the [Fe(C2O4)3]3- complex is and draw it.