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’) NH 2 CH 2 CH 2 NH 2 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(C 2 O 4 ) 2 (H 2 O) 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(C 2 O 4 ) 3 ] 3- with three ethanedioate ions. The ethanedioate ion is a bidentate a)Explain the term “bidentate ligand”. b)What is the coordination number of the [Fe(C 2 O 4 ) 3 ] 3- complex. c)Use your answer to part (b) to suggest what shape the [Fe(C 2 O 4 ) 3 ] 3- complex is and draw it.