(
课件网) Chapter 22 Coordination Chemistry Coordination Chemistry 22 22.1 Coordination Compounds Properties of Transition Metals Ligands Nomenclature of Coordination Compounds 22.2 Structure of Coordination Compounds 22.3 Bonding in Coordination Compounds: Crystal Field Theory Crystal Field Splitting in Octahedral Complexes Color Magnetic Properties Tetrahedral and Square-Planar Complexes 22.4 Reactions of Coordination Compounds 22.5 Applications of Coordination Compounds Coordination Compounds 22.1 Coordination compounds contain coordinate covalent bonds formed by the reactions of metal ions with groups of anions or polar molecules. A coordinate covalent bond is a covalent bond in which one of the atoms donates both of the electrons that constitute the bond. Ammonia, a Lewis base Boron trifluoride a Lewis acid empty unhybridized 2pz orbital A coordinate covalent bond Coordination Compounds Coordination compounds may consist of a complex ion and one or more counter ions. K2[PtCl6] The compound consists of the complex ion PtCl62– and two K+ counter ions. Some coordination compounds do not contain complex ions. Coordination Compounds Most of the metals in coordination compounds are transition metals. Coordination Compounds Properties of transition metals include: incompletely filled d subshells react to form ions with incompletely filled d subshell distinctive colors paramagnetism catalytic activity tendency to form complex ions exhibit variable oxidation state Coordination Compounds Coordination Compounds Coordination Compounds Coordination Compounds The molecules or ions that surround the metal in a complex ion are called ligands. Ligands must contain at least one unshared pair of valence electrons. The atom in the ligand directly bonded to the metal atom is called the donor atom. Coordination Compounds Coordination Compounds The coordination number in a coordination compound refers to the number of donor atoms surrounding the central metal atom in a complex ion. Coordination Compounds Bidentate and polydentate ligands are also called chelating agents Coordination Compounds Bidentate and polydentate ligands are also called chelating agents Worked Example 22.1 Strategy Identify the components of each compound, and use known oxidation states and charges to determine the oxidation state of the metal. Determine the oxidation state of the central metal atom in each of the following compounds: (a) [Ru(NH3)5(H2O)]Cl2, (b) [Cr(NH3)6](NO3)3, and (c) Fe(CO)5. Solution (a) [Ru(NH3)5(H2O)]Cl2 consists of a complex ion (the part of the formula enclosed in a square brackets) and two Cl- counter ions. Because the overall charge on the compound is zero, the complex ion is [Ru(NH3)5(H2O)]2+. There are six ligands: five ammonia molecules and one water molecule. Each molecule has a zero charge (i.e., each ligand is neutral), so the charge on the metal is equal to the overall charge on the complex ion. Ru has ... ...
