1 / 15

Unless otherwise stated, all images in this file have been reproduced from:

Unless otherwise stated, all images in this file have been reproduced from: Blackman, Bottle, Schmid, Mocerino and Wille, Chemistry , 2007 (John Wiley)      ISBN: 9 78047081 0866 . CHEM1002 [Part 2]. A/Prof Adam Bridgeman (Series 1) Dr Feike Dijkstra (Series 2) Weeks 8 – 13

razi
Download Presentation

Unless otherwise stated, all images in this file have been reproduced from:

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Unless otherwise stated, all images in this file have been reproduced from: Blackman, Bottle, Schmid, Mocerino and Wille,Chemistry, 2007 (John Wiley)     ISBN: 9 78047081 0866

  2. CHEM1002 [Part 2] A/Prof Adam Bridgeman (Series 1) Dr FeikeDijkstra (Series 2) Weeks 8 – 13 Office Hours: Monday 2-3, Friday 1-2 Room: 543a e-mail:adam.bridgeman@sydney.edu.au e-mail:feike.dijkstra@sydney.edu.au

  3. Summary of Last Lecture • Complexes I • Solutions of metal ions are acidic because coordinated water loses H+ and this increases with the charge of the metal ion • Ligands use lone pairs to bond to transition metal ions • Coordination compounds are made up of a complex ion, containing a metal ion and ligands, and counter ions to balance the charge • The common geometries of complex ions are tetrahedral and square planar (both 4 coordinate) and octahedral (6 coordinate)

  4. Complexes II • Lecture 13 • Isomerism • Stability • Blackman Chapter 13, Sections 13.1-13.4 • Lecture 14 • Transition Metals • Electron Configuration • Oxidation States • Colours • Magnetism • Blackman Chapter 13, Sections 13.4 and 13.7

  5. Isomerism in Metal Complexes (1) • Structural Isomerism: different atom connectivities • If the counter ions are also potential ligands, they can swap places to produce coordination sphere isomers: [Cr(OH2)4Br2]Cl [Cr(OH2)4BrCl]Br

  6. Isomerism in Metal Complexes (2) • Stereoisomerism: same atom connectivities but different arrangement of atoms in space • geometric isomerism cis trans

  7. Isomerism in Metal Complexes • Stereoisomerism: same atom connectivities but different arrangement of atoms in space • optical isomerism mirror imagessuperposable (i.e. the same!) trans isomer mirror images non-superposable mirror image cisisomer OPTICALLY ACTIVE

  8. Stereoisomerism: same atom connectivities but different arrangement of atoms in space • optical isomerism Isomerism in Metal Complexes [Ni(en)3]3+

  9. Equilibria Involving Complexes • Unlike the covalently bonded polyatomic ions such as NO3-, SO42-, etc., which do not dissociate into their components, metal complexes in solution are in an equilibrium: [M(OH2)6]2++ 6NH3[M(NH3)6]2++ 6H2O [M(NH3)6]2++ 3en [M(en)3]2++ 6NH3

  10. [Ni(en)2(H2O)2]2+ + en[Ni(en)3]2++ 2H2O Stepwise Formation Constants [Ni(H2O)6]2++ 3en [Ni(en)3]2+ + 6H2O [[Ni(en)3]2+] Kstab = = 1018.28 [[Ni(H2O)6]]2+][en]3 K1 [Ni(H2O)6]2++ en[Ni(en)(H2O)4]2+ + 2H2O green blue-green [Ni(en)(H2O)4]2+ + en[Ni(en)2(H2O)2]2+ + 2H2O K2 light blue K3 purple Kstab = K1 K2 K3 = 1018.28

  11. Metal Complex Formation and Solubility • Metal complex formation can greatly influence the apparent solubility of a compound. AgCl(s) + 2NH3(aq)  [Ag(NH3)2]+(aq) + Cl-(aq) • This is actually a two stage process: AgCl(s) Ag+(aq) + Cl-(aq) (1) Ag+(aq) + 2NH3(aq) [Ag(NH3)2]+(aq) (2) • Complex formation (reaction 2), removes free Ag+ from solution and so drives the dissolution of AgCl (reaction 1) forward.

  12. The One Pot Reaction Ag+(aq) + OH-(aq)AgOH(s) brown AgOH(s) + H2PO4-(aq) AgH2PO4(s) yellow AgH2PO4(s) + HNO3(aq) Ag+(aq) + H3PO4(aq) Ag+(aq) + Cl-(aq) AgCl(s) white Ksp = 1.8 x 10-10 M2 AgCl(s) + 2 NH3(aq) [Ag(NH3)2]+(aq) + Cl-(aq) Kstab = 1.7 x 107 M-2 [Ag(NH3)2]+(aq) + Br-(aq) AgBr(s) (green/white), Ksp = 5 x 10-13 M2 AgBr(s) + 2 S2O32-(aq) [Ag(S2O3)2]3-(aq)+Br-(aq) Kstab = 2.5 x 1013 M-2 [Ag(S2O3)2]3-(aq) + I-(aq) AgI(s) (yellow) Ksp = 8.3 x 10-17 M2 AgI(s) + 2 CN-(aq) [Ag(CN)2]-(aq) + I-(aq) Kstab = 6.3 x 1019 M-2 [Ag(CN)2]-(aq) + S2-(aq) Ag2S(s) (black) Ksp = 8 x 10-51 M3

  13. Summary: Complexes II • Learning Outcomes - you should now be able to: • Complete the worksheet • Identify isomers of complexes correctly • Answer review problems 13.59-13.62 in Blackman • Next lecture: • Colour

  14. Practice Examples

  15. Practice Examples

More Related