Download CH 24

CHAPTER 24 – The Chemistry of Coordination Compounds
I.
Review
A. Example of Anionic and Cationic Complex ions
Fe(CN)63−
charge of Fe =
Fe(H2O)63+
charge of Fe =
B. Examples of Coordination Compounds (Contain one or more complex ions)
K3[Fe(CN)6]
water soluble ionic compound
[Fe(H2O)6]2(SO4)3
water soluble ionic compound
[Fe(H2O)6][Fe(CN)6]
water soluble ionic compound
[Fe(NH3)3(CN)3]
water insoluble coordination compound
C. Definitions
1. Central Metal Ion – Lewis Acid
2. Ligand – Lewis Base
3. Coordinate Covalent Bond
4. Coordination Number = number of ligand sites on the central metal ion.
The most common coordination numbers are 2, 4, and 6.
D. Common Ligands – See packet page
1. monodentate ligands
.
2. bidentate ligands
3. polydentate ligands
II.
Nomenclature of Complex Ions and Coordination Compounds
A. Cationic Complex Ions
1. Fe(H2O)63+
2. Pt(NH3)2(CN)22+
B. Anionic Complex Ions
1. Fe(CN)63−
1
2. Pt(ox)22−
3. Co(Cl)4(en)2−
C. Coordination Compounds
1. K3[Fe(CN)6]
2. [Fe(H2O)6]2(SO4)3
3. [Fe(H2O)6][Fe(CN)6]
4. [Cr(H2O)4(CO)2]Cl3
III.
Complex Ion Geometry and Hybridization
A. Coordination Number 2 - Linear Geometry and sp hybridization
Ag(NH3)2+
B. Coordination Number 4 - Tetrahedral Geometry and sp3 hybridization
NiCl42+ (optical isomerism is possible if four different ligands are attached)
C. Coordination Number 4 – Square Planar Geometry and dsp2 hybridization
PtCl2(CN)22− (this ion exhibits geometric isomerism)
D. Coordination Number 6 – Octahedral Geometry and d2sp3 or sp3d2
hybridization
FeCl2(en)2+ (this ion exhibits geometric and optical isomerism)
2
IV.
Isomerism
A. Structural Isomerism
1. Coordination Isomerism
[Cr(NH3)5SO4]Br
[Cr(NH3)5Br]SO4
2. Linkage Isomerism
[Co(NH3)4(NO2)Cl]Cl
[Co(NH3)4(ONO)Cl]Cl
yellow compound
red compound
B. Stereoisomerism
1. Geometric Isomerism
PtCl2(CN)22−
2. Optical Isomerism
Pd(H2O)BrClCN+
FeCl2(en)2+
V.
Crystal Field Theory
A. A Review of d Orbital Geometry
B. Coordination Number 6 (Octahedral Field) Crystal Field Splitting
3
C. Spectrochemical Series
D. High Spin–Low Field versus Low Spin-High Field Complexes
Fe(H2O)62+
H2O is a low field-high, high-spin ligand
Fe(CN)64−
CN− is a high-field, low-spin ligand
E. Color and Magnetism
1. Complementary Colors
2. The complex ion Fe(CO)63+ has an absorption maximum around 410 nm
in the visible sprectrum. What color will a solution of this complex ion
be?
F. Magnetic Properties
Fe(CN)64− versus Fe(H2O)62+
4