Part 2.8: Coordination Chemistry - PowerPoint Presentation

1. Part 2.8: Coordination Chemistry1

2. OutlineCoordination ComplexesHistoryLigandsIsomersInorganic BondingCrystal Field TheoryLigand Field TheoryOrbital DiagramsLigand Field Jahn-Teller DistortionBioinorganic Chemistry2

3. Ancient times through Alchemy:Descriptive chemistry, techniques, minerals (Cu compounds), glasses, glazes, gunpowder17th CenturyMineral acids (HCl, HNO3, H2SO4), salts and their reactions, acid and basesQuantitative work became important, molar mass, gases, volumes1869: The periodic tableLate 1800s: Chemical Industry Isolate, refine, purify metals and compounds1896: Discovery of RadioactivityAtomic structure, quantum mechanics, nuclear chemistry (through early 20th century)History of Inorganic Chemistry3

4. Inorganic History Side NoteFriedrich Wöhler (1828)Potassium CyananteAmmonium SulfateAmmonium CyananteUrea“I can no longer, so to speak, hold my chemical water and must tell you that I can make urea without needing a kidney.” Wöhler in a letter to Berzelius

5. 20th CenturyCoordination chemistry, organometallic chemistryWWII & Military projects: Manhattan project, jet fuels (boron compounds)1950sCrystal field theory, ligand field theory, molecular orbital theory1955Organometallic catalysis of organic reaction (polymerization of ethylene)History of Inorganic Chemistry5

6. Metal Coordination ComplexesCoordination complexes or coordination compounds- consists of a central atom, which is usually metallic, and a surrounding array of bound molecules or ions, that are in turn known as ligands or complexing agents.Stable in light and air.Accidentally discovered while trying to make a red dye (1705).Prussian blueIron-hexacyanoferrate First synthetic blue dye.Known for centuries.6

7. Prussian blueIron-hexacyanoferrate Metal Coordination ComplexesThe Great Wave off KanagawaStarry NightStructure of coordination complexes not understood until 1907. 7

8. Metal Coordination ComplexesLigands are ions or neutral molecules that bond to a central metal atom or ion.Denticity refers to the number of donor groups in a single ligand that bind to a central atom in a coordination complex. Ligand biting the metal. M = transition metalL = ligandMonodentate (one tooth)Bidentate (two teeth)Polydentate (many teeth)8

9. Monodentate Ligands9

10. Bidentate Ligands10

11. Polydentate Ligands11

12. EDTA ethylenediaminetetraacetateLigands that bind to more than one site are called chelating agents.M = Mn(II), Cu(II), Fe(III), Pb (II) and Co(III)Added to foods to prevent catalytic oxidationIn cleaning solutions (reduce water hardness)Chelation therapy for Hg and Pb poisoningAnalytical titrations12

13. Coordination Complex IsomersThe same connectivities but different spatial arrangements.Different connectivities (same formula).13

14. Coordination IsomersSame formula different bonding to the metal.[Cr(NH3)5SO4]Br and [Cr(NH3)5Br]SO4 Co + (NH3)5 + Cl + Br[Co(NH3)6]3+ and [Cr(CN)6]3-) [Cr(NH3)6]3+and [Co(CN)6]3-Cr + (NH3)5 + SO4 + BrCo + Cr + (NH3)6 + (CN)614

15. Linkage IsomersComposition of the complex is the same, but the point of attachment of the ligands differs.Formula NameNO2- nitrito (via O)NO2- nitro (via N)15

16. Linkage IsomersThe compounds have different properties and colors.Linear vs. bent nitrosylN or S bond thiocyanateM-NCS M-SCN16

17. Geometric IsomersIn geometric isomers, the ligands have different spatial arrangements about the metal ion.Square planar complexes like [MX2Y2].Example: [Pt(NH3)2Cl2].Octahedral complexes like [MX4Y2].Example: [Pt(NH3)4Cl2].17

18. Geometric IsomersOctahedral complexes with the formula [MX3Y3] can be fac (facial) or mer (meridional).In geometric isomers, the ligands have different spatial arrangements about the metal ion.18

19. Optical IsomersOptical isomers are compounds with non-superimposable mirror images (chiral molecules).C1, Cn, and Dn also T, O, and IChiral molecules lack an improper axis of rotation (Sn), a center of symmetry (i) or a mirror plane (σ)!Common for octahedral complexes with three bidentate ligands. 19

20. Optical IsomersCan be viewed like a propeller with three blades.20

21. Optical IsomersCo(en)2Cl2Not Optically activeOptically active21

22. OutlineCoordination ComplexesHistoryLigandsIsomersInorganic BondingCrystal Field TheoryLigand Field TheoryOrbital DiagramsLigand Field Jahn-Teller DistortionBioinorganic Chemistry22

23. Organic Bonding1857- Kekule proposes the correct structure of benzene. 1856- Couper proposed that atoms joined to each other like modern-day Tinkertoys. Oxalic acidEthanol23

24. Inorganic ComplexesLate 1800s- Blomstrand and JorgensonCo3+, 4 x NH3, 3 x ClTheir rulesCharge on the metal ion determined the number of bonds- Co3+ = 3 bondsSimilar bonding concepts to organicsNH3 can form chains like -CH2-Only Cl- attached to an NH3 could dissociateDid not explain isomers.24

25. Inorganic Complexes1893- Werner’s TheoryCo3+, 6 x NH3, 3 x ClHis rulesMetals interact with 6 ligands in octahedral geometry to form “complex ions”Primary/inner coordination sphere: bound to metalSecondary/outer coordination sphere: balance chargeBlomstrand StructureWerner Structure25

26. Werner’s TheoryExplains multiple complexes of the same sets of ligands in different numbers[Co(NH3)6]Cl3 [Co(NH3)5Cl]Cl2 [Co(NH3)4Cl2]Cl [Co(NH3)3Cl3]Different numbers of ions are produced due to outer sphere dissociationExplains multiple complexes with exact same formula = isomersWerner Complexes26

27. Werner’s Other ContributionsWerner ComplexesCoordination Number = Most first row transition elements prefer 6 ligands. Pt2+ prefers 4 ligands.CoA4B2 only has two isomers. Not trigonal prismatic because trigonal antiprimatic because they would give 3 isomers. Octahedral because it only has two possible isomers. PtA2B2 only has two isomers so it must be square planar. Tetrahedral would have only 1 isomer.Water completes the Inner Sphere coordination in aqueous solutions: NiCl2 + H2O [Ni(H2O)6]Cl2 27

28. Werner’s Other ContributionsWerner ComplexesIn 1914, Werner resolved hexol, into optical isomers, overthrowing the theory that only carbon compounds could possess chirality.28

29. Werner ComplexesWerner was awarded the Nobel Prize in 1913 (only inorg. up until 1973)29

30. Coordination ComplexesShortcomings of Werner’s TheoryDoes not explain the nature of bonding withing the coordination sphere.Does not account for the preference between 4- and 6- coordination. Does not account for square planar vs tetrahedral.Crystal Field TheoryLigand Field Theory30

31. Crystal Field TheoryElectrostatic approach to bonding.First Applied to ionic crystalline substances.Assumptions:Metal ion at the center.Ligands are treated as point charges.Bonding occurs through M+ and L- electrostatic attraction. Bonding is purely ionic.M and L electrons repel each other.d orbital degeneracy is broken as ligands approach. 31

32. Crystal Field Theory32

33. Octahedral SplittingEMd-orbitals align along the octahedral axis will be affected the most.dz2 dx2-y2 dxy dyz dxz33

34. dx2-y2dz2dxzdxydyzTetrahedral SplittingTetrahedral34

35. Other Geometries35

36. Other Geometries36

37. Crystal Field TheoryMerits of crystal field theory:Can be used to predict the most favorable geometry for the complex.Can account for why some complexes are tetrahedral and others square planar.Usefull in interpreting magnetic properties.The colors of many transition metal complexes can be rationalized.Limitations of crystal field theory:Becomes less accurate as delocalization increases (more covalent character).Point charge does not accurately represent complexes. Does not account for pi bonding interactions.Does not account for the relative strengths of the ligands.37

38. Ligand Field TheoryApplication of molecular orbital theory to transition metal complexes.Ligands are not point charges.Takes into account p bonding. Can be used to explain spectrochemical series. Better than valence-bond model or crystal field theory at explaining experimental data.38

39. OutlineCoordination ComplexesHistoryLigandsIsomersInorganic BondingCrystal Field TheoryLigand Field TheoryOrbital DiagramsLigand Field Jahn-Teller DistortionBioinorganic Chemistry39

40. Coordination ComplexesHistoryLigandsIsomersInorganic BondingCrystal Field TheoryLigand Field TheoryOrbital DiagramsLigand Field Jahn-Teller DistortionBioinorganic ChemistryOutlineOctahedrals bondingp bondingLigand Field StrengthSquare Planars bondingp bondingTetrahedralOrganometallics 40

41. Octahedral s Only MOsAssign a point groupChoose basis functionApply operations -if the basis stays the same = +1 -if the basis is reversed = -1 -if it is a more complicated change = 0 Generate a reducible representationH s orbitalsOhGFs6002in-between H200042through H-M-H41

42. Octahedral s Only MOsAssign a point groupChoose basis functionApply operations -if the basis stays the same = +1 -if the basis is reversed = -1 -if it is a more complicated change = 0 Generate a reducible representationReduce to irreducible representationCombine orbitals by their symmetryFill MOs with e-Generate SALCs of peripheral atoms Draw peripheral atoms SALC with central atom orbital to generate bonding/antibonding MOs.H s orbitalsOh42

43. Octahedral s Only MOsReduce to irreducible representationGHs6002200042GHs: A1g + T1u + Eg43

44. Octahedral s Only MOsIrreducible reps for M orbitalssdp44

45. T1uT1uEgOctahedral s Only MOsCombine the orbital's by their symmetryM6 x HA1gT1u4s4pEgT1uA1gA1gEgT2g3dEg,T2gA1gDo45

46. Octahedral s Only MOsCombine the orbital's by their symmetryMLEgEgEgT2g3dEg,T2gDo46

47. Octahedral s Only MOsCombine the orbital's by their symmetryEgEgEgT2gEg,T2gDoEgEgEgT2gEg,T2gDoWeak s donorWeak Lewis baseWeaker bonding interactionWeak FieldSmaller DoMLMLStronger s donorStrong Lewis baseStronger bonding interactionStrong FieldLarger Do47

48. Octahedral s Only MOsCombine the orbital's by their symmetryDo: I-   <   Br-   <   Cl-   <   F-Stronger Lewis base = Larger Do Smaller ligands = Larger Do48EgEgEgT2gEg,T2gDoEgEgEgT2gEg,T2gDoMLML

49. Octahedral s Only MOsCombine the orbital's by their symmetryM6 x HAgT1u4s4pEgT1uA1gEgA1gEgT2g3dEg,T2gT1uA1gT1uDo49

50. Fill MOs with e-Generate SALCs of peripheral atomsDraw peripheral atoms SALC with central atom orbital to generate bonding/antibonding MOs.50

51. Octahedral s Only MOsAgT1u4s4pEgT1uA1gEgA1gEgT2g3dEg,T2gT1uA1gT1uGHs: A1g + T1u + Egs obitalsp obitalsGp: A1g + T1u + EgWhat about p orbitals?ML51

52. Octahedral s + p MOs52

53. Assign a point groupChoose basis function (p bonds)Apply operations -if the basis stays the same = +1 -if the basis is reversed = -1 -if it is a more complicated change = 0 Generate a reducible representationReduce to irreducible representationp orbitalsOhGLp12000in-between L-400000through L-M-LOctahedral s + p MOsGLp = T1g + T2g + T1u + T2u53

54. Combine the orbital's by their symmetryMLAgT1u4s4pEgT1uA1gEgA1gEgT2g3dEg,T2gT1uA1gT1uOctahedral s + p MOss orbitalsGLp = T1g + T2g + T1u + T2up orbitalsT2gT1gT1uT2u54

55. Combine the orbital's by their symmetryMLAgT1u4s4pEgT1uA1gA1gEg3dEg,T2gEgT2gT1uA1gT1uOctahedral s + p MOss orbitalsp orbitalsT2gT1gT1uT2u55

56. Combine the orbital's by their symmetryM-LsEgT2gOctahedral s + p MOsT2gfilled donor basedonates to MT2gEgT2gT2gEgT2gT2gDoDoDoempty acceptor acidaccepts from M56

57. Strong FieldWeak FieldDoDoLigand Field StrengthFilled p donor baseDonates to MEmpty p acceptor acidAccepts from Mt2gt2gegegWeak s donorWeak Lewis baseWeaker bonding interactionStronger s donorStrong Lewis baseStronger bonding interactionp bondings bonding57

58. Pure s donating ligands: Do: en > NH3 donating ligands:Do : H2O > F > RCO2 > OH > Cl > Br > I accepting ligands:Do : CO, CN-, > phenanthroline > NO2- > NCS-Ligand Field StrengthDoDot2gt2gegegThe Spectrochemical SeriesCO, CN- > phen > NO2- > en > NH3 > NCS- > H2O > F- > RCO2- > OH- > Cl- > Br- > I-Note:Do increases with increasing formal charge on the metal ionDo increases on going down the periodic table (larger metal)58

59. Ligand Field StrengthDoDot2gt2gegegThe Spectrochemical SeriesCO, CN- > phen > NO2- > en > NH3 > NCS- > H2O > F- > RCO2- > OH- > Cl- > Br- > I-Larger Do Smaller Do Why do we care?Predict/Tune/Understand the:Photophysical properties of metal coordination complexes.Magnetic properties of metal coordination complexes.And others.59

60. Increasing The Spectrochemical SeriesCO, CN- > phen > NO2- > en > NH3 > NCS- > H2O > F- > RCO2- > OH- > Cl- > Br- > I-Larger Do Smaller Do Photophysical Properties60

61. d1d2d3d4Strong fieldWeak fieldStrong fieldWeak fieldMagnetic Properties61

62. Pairing Energy, PThe pairing energy, P, is made up of two parts. Coulombic repulsion energy caused by having two electrons in same orbital. Destabilizing energy contribution of Pc for each doubly occupied orbital.High EnergyExchange stabilizing energy for each pair of electrons having the same spin and same energy. Stabilizing contribution of Pe for each pair having same spin and same energy.Medium EnergyHund's RulesLess repulsionLess p+ screeningLow EnergyMedium Energy62

63. Side note: Exchange Energy, PeExcitationInternal ConversionFluorescenceNon-radiative decayIntersystem CrossingPhosphorescenceS0S1S2ET1Ground State (S0)Singlet Excited State (S1)Triplet Excited State (T1)DEST ≈ Pe≈ 2Je63

64. Pairing Energy, PThe pairing energy, P, is made up of two parts. Coulombic repulsion energy caused by having two electrons in same orbital. Destabilizing energy contribution of Pc for each doubly occupied orbital.High EnergyExchange stabilizing energy for each pair of electrons having the same spin and same energy. Stabilizing contribution of Pe for each pair having same spin and same energy.Medium EnergyHund's RulesP = sum of all Pc and Pe interactionsLess repulsionLess p+ screeningLow EnergyMedium EnergyHigh EnergyLow Energy64

65. d4Strong field =Low spin(2 unpaired)Weak field =High spin(4 unpaired)P < Do P > Do When the 4th electron will either go into the higher energy eg orbital at an energy cost of D0 or be paired at an energy cost of P, the pairing energy.P vs. DoDoDo65

66. 1 u.e.5 u.e.d50 u.e.4 u.e.d61 u.e.3 u.e.d72 u.e.2 u.e.d81 u.e.1 u.e.d90 u.e.0 u.e.d10Magnetic Properties66

67. Magnetic PropertiesThe Spectrochemical SeriesCO, CN- > phen > NO2- > en > NH3 > NCS- > H2O > F- > RCO2- > OH- > Cl- > Br- > I-Larger Do Smaller Do High SpinLow SpinDiamagnetic- all electrons paired.Paramagnetic- unpaired electrons.67

68. Pure s donating ligands: Do: en > NH3 donating ligands:Do : H2O > F > RCO2 > OH > Cl > Br > I accepting ligands:Do : CO, CN-, > phenanthroline > NO2- > NCS-Ligand Field StrengthDoDot2gt2gegeg68The Spectrochemical SeriesCO, CN- > phen > NO2- > en > NH3 > NCS- > H2O > F- > RCO2- > OH- > Cl- > Br- > I-Larger Do Smaller Do

69. Coordination ComplexesHistoryLigandsIsomersInorganic BondingCrystal Field TheoryLigand Field TheoryOrbital DiagramsLigand Field Jahn-Teller DistortionBioinorganic ChemistryOutlineOctahedrals bondingp bondingLigand Field StrengthSquare Planars bondingp bondingTetrahedralOrganometallics 69

70. Square Planar70

71. Square Planar MOsp orbitals of LD4hUse a local coordinate system on each ligand with:y pointing in towards the metal. (py = s bonding)z being perpendicular to the molecular plane. (pz = p^ bonding)x lying in the molecular plane. (px = p|| bonding)Assign a point groupChoose basis function (p orbitals of L)s orbitals (py)p orbitals (px,z)71

72. Square Planar MOsp orbitals of LD4hs orbitals (py)Assign a point groupChoose basis function (p orbitals of L)Apply operations -if the basis stays the same = +1 -if the basis is reversed = -1 -if it is a more complicated change = 0 Gs(py): A1g + B1g + Eu72

73. Square Planar MOsp orbitals of LD4hs orbitals (py)Assign a point groupChoose basis function (orbitals)Apply operationsGenerate a reducible representationReduce to irreducible representationCombine orbitals by their symmetryGs(py): A1g + B1g + Eu73

74. 74Square Planar MOsIrreducible reps for M orbitalssdp

75. Square Planar MOs75

76. p Bonding in Square Planar MOsp orbitals of LD4hp orbitals (px,z)76

77. p Bonding in Square Planar MOs77

78. Complete Square Planar MOs78

79. Coordination ComplexesHistoryLigandsIsomersInorganic BondingCrystal Field TheoryLigand Field TheoryOrbital DiagramsLigand Field Jahn-Teller DistortionBioinorganic ChemistryOutlineOctahedrals bondingp bondingLigand Field StrengthSquare Planars bondingp bondingTetrahedralOrganometallics79

80. s Only Td MOs80Gs41002Gs: A1 + T2

81. s Only Td SALCf1f2f3f481Gs: A1 + T2

82. s Only Td MOs82

83. Coordination ComplexesHistoryLigandsIsomersInorganic BondingCrystal Field TheoryLigand Field TheoryOrbital DiagramsLigand Field Jahn-Teller DistortionBioinorganic ChemistryOutlineOctahedrals bondingp bondingLigand Field StrengthSquare Planars bondingp bondingTetrahedralOrganometallics 83

84. Organometallic ChemistryOrganometallic compound- a complex with direct metal-carbon bonds.Zeise’s salt- the first organometallic compoundIsolated in 1825 (by William Zeise)Structure confirmed in 1838.84

85. p-bonding Ligands85

86. History of FerrocenePauson and Kealy (1951 ) orange solid of "remarkable stability"FeCl3+FulvaleneNature 1951, 168, 1039 - 1040G. Wilkinson, M. Rosenblum, M. C. Whiting, R. B. Woodward Journal of the American Chemical Society 1952, 74, 2125–2126.Wilkinson and Fischer (1952) E. O. Fischer, W. Pfab  Zeitschrift für Naturforschung B 1952, 7, 377–379.86

87. The first sandwich complex.Fuel additives-anitknocking agents.Electrochemical standard.Some derivatives show anti-cancer activity.Small rotation barrier (~ 4 kJmol‐1) and ground state structures of ferrocene can be D5d or D5h.FerroceneD5dD5hD5What about the bonding?87

88. p MOs of CyclopentadienylC5H5-D5hDecomposition/Reduction Formula88

89. p MOs of CyclopentadienylGenerate SALCEnergy increases as the # of nodes increases.89

90. p MOs of FerroceneC5H5-D5hFe(C5H5)2D5d90

91. Decomposition/Reduction Formulap MOs of FerroceneFe(C5H5)2D5d91

92. Generate SALCp MOs of FerroceneFrom the equationAssemble 2 x C5H5-92

93. p MOs of Ferrocene2 x93

94. p MOs of Ferrocene94

95. p MOs of FerroceneD5hD5dA2”E1 ”E1 ”E2”E2”E2gE2uE2gE2uE1gE1uE1gE1uA2uA1g95

96. p MOs of Ferrocene96

97. p MOs of Ferrocene97

98. p MOs of Ferrocene98

99. p MOs of Ferrocene99

100. p MOs of Ferrocene100

101. OutlineCoordination ComplexesHistoryLigandsIsomersInorganic BondingCrystal Field TheoryLigand Field theoryOrbital DiagramsLigand Field Jahn-Teller DistortionBioinorganic Chemistry101

102. Jahn-Teller DistortionJahn-Teller theorem: “there cannot be unequal occupation of orbitals with identical energy”Molecules will distort to eliminate the degeneracy!EDistortiond31 u.e.1 u.e.d9equal occupationunequal occupation102

103. egt2gEdxzdx2-y2dyzdxydz2Jahn-Teller Distortion[Cu(H2O)6]2+2.45 Å2.00 Å103

104. Jahn-Teller Distortion104

105. Jahn-Teller Distortion105

106. OutlineCoordination ComplexesHistoryLigandsIsomersInorganic BondingCrystal Field TheoryLigand Field theoryOrbital DiagramsLigand Field Jahn-Teller DistortionBioinorganic Chemistry106

107. Transition Metals in Biochemistry107

108. Transport/storage proteins : Transferrin (Fe) Ferritin (Fe) Metallothionein (Zn) O2 binding/transport: Myoglobin (Fe) Hemoglobin (Fe) Hemerythrin (Fe) Hemocyanin (Cu) Enzymes (catalysts) Hydrolases: Carbonic anhydrase (Zn) Carboxypeptidase (Zn) Oxido-Reductases: Alcohol dehydrogenase (Zn) Superoxide dismutase (Cu, Zn, Mn, Ni) Catalase, Peroxidase (Fe) Nitrogenase (Fe, Mo) Cytochrome oxidase (Fe, Cu) Hydrogenase (Fe, Ni) Isomerases: B12 coenzymes (Co) Aconitase (Fe-S) Oxygenases: Cytochrome P450 (Fe) Nitric Oxide Synthases (Fe) Electron carriers: Cytochromes (Fe) Iron-sulfur (Fe) Blue copper proteins (Cu) Metals in Biochemistry Structural Skeletal roles via biomineralization Ca2+, Mg2+, P, O, C, Si, S, F as anions, e.g. PO43, CO32. Charge neutralization. Mg2+, Ca2+ to offset charge on DNA - phosphate anions Charge carriers: Na+, K+, Ca2+ Transmembrane concentration gradients ("ion-pumps and channels") Trigger mechanisms in muscle contraction (Ca). Electrical impulses in nerves (Na, K) Heart rhythm (K). Hydrolytic Catalysts: Zn2+ , Mg2+ Lewis acid/Lewis base Catalytic roles. Small labile metals. Redox Catalysts: Fe(II)/Fe(III)/Fe(IV), Cu(I)/Cu(II), Mn(II)/Mn(III)/(Mn(IV), Mo(IV)/Mo(V)/Mo(VI), Co(I)/Co(II)/Co(III) Transition metals with multiple oxidation states facilitate electron transfer - energy transfer. Biological ligands can stabilize metals in unusual oxidation states and fine tune redox potentials. Activators of small molecules. Transport and storage of O2 (Fe, Cu) Fixation of nitrogen (Mo, Fe, V) Reduction of CO2 (Ni, Fe) Organometallic Transformations. Cobalamins, B12 coenzymes (Co), Aconitase (Fe-S)108

109. Transition Metals in Biochemistry109

110. Amino acid binding functionalities: -OH, -SH, -COOH, -NH, CONH2Biological Ligands110

111. Biological Ligands111

112. Bioinorganic Chemistry112

113. Bioinorganic ExamplesHemoglobin iron-containing oxygen-transport metalloprotein in the red blood cells of all vertebrates.hemoglobin in the blood carries oxygen from the respiratory organs (lungs or gills) to the rest of the body.113

114. Bioinorganic ExamplesNitrogenaseReduction of N2 to 2NH3 + H2 Fe7MoS9 cluster  Mechanism not fully known.Mo sometimes replaced by V or Fe.Inhibited by CO.114

115. Bioinorganic ExamplesIron Sulfur ClustersMediate electron transport.“Biological capacitors”Fe(II) and Fe(III)Found in a variety of metalloproteins, such as the ferredoxins, hydrogenases, nitrogenase, cytochrome c reductase and others.Ferredoxin115

116. Metal Ions and Life116

117. Not Enough Metal Ions117

118. Argyria or argyrosis: a condition caused by inappropriate exposure to chemical compounds of the element silver.Excess Metal IonsColloidal SilverPaul Karason- Used silver to “treat” dermatitis, acid reflux and other issues.Food and Drug Administration (FDA) doesn't approve of colloidal silver as a medical treatment!118

119. To Much Ag119

120. OutlineCoordination ComplexesHistoryLigandsIsomersInorganic BondingCrystal Field TheoryLigand Field theoryOrbital DiagramsLigand Field Jahn-Teller DistortionBioinorganic Chemistry120