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Chemistry 204 Dr. Christine Yerkes 207 Chem Annex 333-6353 [email protected] Mon. - Fri. 1:00 - 2:00 or by appointment Required Text: Chemical Principles, 5th ed., Zumdahl electronic calculator with log functions Quiz sections begin: Wed, Jan. 18 Grading Policy: On-line Homework: Quiz score: Hour Exams (3 x 150) Final Exam TA evaluation 85 pts. 150 pts. 450 pts. 300 pts. 15 pts. 1000 pts. No make-up quizzes or exams Grades 1000 points total 97-100% (970 - 1000) = A+ 93 - 96% (930 - 969) = A 90 - 92% (900 - 929) = Aetc., etc., etc. Quiz scores: weekly quizzes - material from previous week (lecture and Quiz section) each quiz worth 15 points - keep 10 highest TA evaluation - 15 points 165 points On-line Homework: 8 Homework assignments on LON-CAPA due dates on line credit for all problems completed before deadline 85 points LON-CAPA http:// www.chem.uiuc.edu Chem 204 user name : net i.d. password : Active Directory (AD) password homepage CITES Transition metals and coordination chemistry Alfred Werner CoCl3 . 6 NH3 CoCl3 . 5 NH3 CoCl3 . 4 NH3 CoCl3 . 3 NH3 Co has 6 ligands 100% 66% AgCl (s)with NH3 + AgNO HCl 3 no reaction 33% [Co(NH3)6] Cl3 [Co(NH3)5Cl] Cl2 [Co(NH3)4Cl2] Cl [Co(NH3)3Cl3] 0% Transition metals and coordination chemistry [Co(NH3)6] Cl3 1 isomer [Co(NH3)5Cl] Cl2 [Co(NH3)4Cl2]Cl [Co(NH3)4Cl2]Cl [Co(NH3)3Cl3] 1 isomer 2 isomers 2 isomers Cl NH3 H3N NH3 Co octahedral H3N all positions equivalent NH3 NH Cl 3 Transition metals and coordination chemistry Lewis acid – Lewis base coordinate covalent bond e- pair donor lone pair e- on ligands e- pair acceptor metals empty orbitals 1. oxidation state 2. coordination number Transition metals and coordination chemistry Lewis acid – Lewis base coordinate covalent bond e- pair donor lone pair e- on ligands e- pair acceptor metals empty orbitals 1. oxidation state Transition metals Sc Ti 4s12 V Cr Mn Fe Co Ni Cu Zn 3d1 3d2 3d3 3d5 3d5 3d6 3d7 3d8 3d10 3d10 s electrons lost first Fe2+ 3d6 Cu+ first-row ions do not have s e- Transition metals and coordination chemistry Lewis acid – Lewis base coordinate covalent bond e- pair donor lone pair e- on ligands e- pair acceptor metals empty orbitals 1. oxidation state 2. coordination number # lone pairs ligands ligands .. H 2O .. aqua NH3 ammine monodentate CN- cyano O O C oxalate C - O OM H2C H2N CH2 ethylenediamine NH2 (en) M tridentate diethylenetriamine (dien) polydentate (6) EDTA bidentate chelate Nomenclature p. 496 [Co(NH3)6] Cl3 hexaamminecobalt(III) chloride [Co(NH3)3Cl3] triamminetrichlorocobalt(III) K2[CuCl4] potassium tetrachlorocuprate(II) [CoCl2(en)2]Cl dichlorobis(en)cobalt (III) chloride 1. cation anion 2. ligands (alphabetical) before metal, with prefixes 3. oxidation state of metal in (roman numerals) Isomerism same formula different properties structural isomers different bonds coordination isomerism linkage isomerism [CoSO4(NH3)5]Br N O O [CoBr(NH3)5]SO4 O N O Co SO4 Br H3N NH3 H3N Co H3N Co NH3 NH3 NH3 H3N NH3 NH3 Isomerism same formula different properties stereoisomers different spatial arrangement geometric isomerism optical isomerism [Co(NH3)4Cl2] Cl trans- cis- Cl Cl H3N NH3 H3N Co H3N Co NH3 Cl NH3 H3N Cl NH3 optical isomerism differ biologically differ in “plane polarized light” Cl Cl H2O NH3 Co Br Co NH3 NH3 OH2 H3N Br H3N NH3 non-superimposable mirror images enantiomers chiral “hands” plane of symmetry chiral no plane of symmetry