Clicker Question22: Coordination ChemistryCommon Ligands to KnowChelating LigandsCoordination NumberCoordination NumberGeometry of Coordination ComplexesGeometry of Coordination ComplexesIsomerism in Coordination ComplexesIsomerism in Coordination ComplexesIsomerism in Coordination ComplexesIsomerism in Coordination ComplexesIsomerism in Coordination ComplexesIsomerism in Coordination ComplexesOptical Isomerism ExamplesCoordination Compounds & LifeCoordination Compounds & LifeFinding the Metal d-electron countCrystal Field TheoryCrystal Field TheoryCrystal Field TheoryClicker QuestionA coordination compound is one thata. Is formed between alkali metals or alkaline earths and halogensb. Is formed from a transition metal, ligands, and enough counter ions to produce a neutral compoundc. Aids in bannce, and is found at enhanced levels in elite gymnasts and dancersd. Results from a neutralization reactione. Is formed when elements of the third period react with halogens22: Coordination Chemistry22.1 Properties of the Transition Elements 22.2 Iron and Steel: The Use of Pyrometallurgy22.3 Copper: A Coinage Metal22.4 Silver and Gold: The Other Coinage Metals22.5 Chromium22.6 Coordinate Covalent Bonds22.7 Crystal-Field TheoryFriday, October 31, 2014Read: Section 22.1 for Friday Sections 22.2, 22.3 and 22.4 MondayEnd of Chapter 22 Problems: 8, 14, 16, 18, 20, 21, 22, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 63, 65, 67, 73, 75, 77, 78, 79, 83, 85, 91Friday, October 31, 2014Read: Section 22.1 for Friday Sections 22.2, 22.3 and 22.4 MondayEnd of Chapter 22 Problems: 8, 14, 16, 18, 20, 21, 22, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 63, 65, 67, 73, 75, 77, 78, 79, 83, 85, 91Common Ligands to KnowMonodentate ligandsOH HNH HH-Water Ammonia Chloride ion Cyanide ion Carbon monoxide Hydroxide ionC ≡ N-C = OO–H-ClN–CH2–CH2–NCH2–C–O CH2–C–O ||O||O||O||OO–C–CH2 O–C–CH2 Hexadentate ligand4-Ethylenediaminetetraacetate ion (EDTA)Bidentate ligandsO||CO OOOC–COOH2C–CH2NH2H2NNN2-2-Carbonate ion Oxalate ion (ox)Ethylenediamine Ortho-phenanthroline (en) (phen)Chelating LigandsChelating ligands “grab” metal ions.They are polydentate ligands (donating ≥ 2 e-pairs).EDTA is hexadentate. 6 coordinate covalent bonds form:•2 N atoms (blue spheres)•4 O atoms (red spheres)EDTA encapsulates insolublemetal ions, making them soluble.MCoordination NumberCoordination number = number of coordinate covalent bonds between a metal ion and its ligands Coordination Examples Number2 [Ag(NH3)2]+, K[AuCl2]4 [Pt(NH3)4]2+, K2[NiCl4]6 [Fe(H2O)6]2+, [Co(NH3)6]Cl3One-bond ligands = monodentate (CN = 1)Two-bond ligands = bidentate (CN = 2)Denticity of a ligand[Co(en)3]3+Coordination Number•A Co3+ coordination complex contains two ethylenediamine (en) ligands and two chloride ligands. Determine the coordination number for this complex. [Co(en)2Cl2]+1. 32. 43. 54. 6n+2ML complexes are linearML complexes are octahedraln+6Geometry of Coordination Complexes[Co(NH3)6]3+[Cl – Cu – Cl]-[Ag(NH3)2]+n+4ML complexes are square planar or tetrahedralGeometry of Coordination ComplexesSquare PlanarTetrahedral[Pt(NH3)4]2+[Zn(NH3)4]2+Linkage isomerism Some ligands can bind in multiple ways:Isomerism in Coordination Complexes pentaamminethiocyanatocobalt(III) ion pentaammineisothiocyanatocobalt(III) ionM-SCN M-NCSGeometric isomerism (square planar & octahedral complexes)cis = adjacent trans = opposite sidescis-[Pt(NH3)2Cl2] trans-[Pt(NH3)2Cl2]cis-diamminedichloroplatinum(II) trans-diamminedichloroplatinum(II)The isomers differ in solubility, color, m.p, and reactivityThe cis-isomer is an anticancer agent (cisplatin)The trans-isomer is inactiveIsomerism in Coordination ComplexesAn octahedral complex example: violet green cis = adjacent trans = opposite sidescis-[Co(NH3)4Cl2]+ trans-[Co(NH3)4Cl2]+cis-tetraamminedichlorocobalt(III) trans-tetraamminedichlorocobalt(III)ion ionIsomerism in Coordination ComplexesGeometric isomerism (octahedral complexes) facial (fac) meridinal (mer)Forms a face of the octahedron Connect the meridian of the octahedronfac-Co(NH3)3Cl3mer-Co(NH3)3Cl3fac-triamminetrichlorocobalt(III) mer-triamminetrichlorocobalt(III)Isomerism in Coordination ComplexesWhich of the following is the correct structure for:potassium cis-dibromodichloroplatinate(II)Isomerism in Coordination Complexes1234Optical isomerism also occurs (enantiomers) Enantiomers: Non-superimposable mirror images Isomerism in Coordination Complexes[Cr(en)2Cl2]+dichlorobis(ethylenediamine)chromium(III) ionOptical Isomerism ExamplesCoordination Compounds & LifeHeme carries Fe2+ in myoglobin and hemoglobin*1 heme/myoglobin and 4 hemes/hemoglobin.2+Coordination Compounds & LifeVitamin B12:6-coord. Co ion bound to a heme ligandOnly known dietary use of cobalt, but it is absolutely essentialFinding the Metal d-electron countTake into account the charges of any counter ionsDetermine which ligands are neutral and which are charged (anionic) to determine ox. stated-count = valance electrons – oxidation stateNOT dependent on isomers!Crystal Field TheoryOrbital view- pay attention to axis labels!Crystal Field Theorye-pairs on the ligands create an electrostatic field.Crystal Field TheoryThis field interacts with the metal-ion d orbitals.CN-FeCN-CN-CN-CN-CN-2+3dz23dx - y2 2Along the x, y, z axes3dyz3dxy3dxzBetween axes•Ligands lie along the x, y and z axes.•The two types of d orbitals have different E in this field.In an octahedral