《基础化学》英文教学课件：chapter_11

配体
外层
Inner sphere 内层
Coordination compound 配位化合物
§1. Basic Concepts
1. Central atom(中心原子)
A Central atom resides at the center of a coordination compound. Generally, the central atom is transition metal cation ([Cu(NH3)4]2+， [Zn(OH)4]2-) or neutral atom (Fe(CO)5), which have unoccupied orbital to accept electron pairs from ligands.
:C O:
:
: ::
thiocyanate(硫氰根) :S—C— —N: – isothiocyanate(异硫氰根) :N—C—S: –
§1. Basic Concepts
Cations only rarely function as ligands because an electron pair on a cation is held securely by the positive charge.
Chapter 11. Coordination Compounds
§ 11-1. Basic Concepts § 11-2. Valence Bond Theory of Complexes § 11-3. Complex-Ion Equilibrium § 11-4. Chelate and Biological Ligands § 11-5. Medical Applications of Complexes
NH3
H3N Cu NH3
NH3
[SiF6]2-
§1. Basic Concepts
2. Ligand(配体)
Ligands are neutral molecules or anions that attached
to the central atom via coordinate covalent bond, they
§1. Basic Concepts
II. Composition of coordination compound
配位原子 Ligating atom
配位数 Number of ligands
[Cu
(NH3)4]2+
SO42-
Central atom Ligand
Outer sphere
中心原子
Zn(OH)2 + 2H+ = Zn2+ + 2H2O With a base, Zn(OH)2 reacts to form a complex ion:
Zn(OH)2 + 2OH- = Zn(OH)42-
§1. Basic Concepts
I. Definition of coordination compound
Experiment 2 Zn2+ NaOH Zn(OH)2
Zn(OH)42-
Zn2+ + 2OH- = Zn(OH)2 Amphoteric hydroxide Zinc hydroxide reacts with a strong acid and the metal hydroxide dissolves:
Cu2+ + 2OH- = Cu(OH)2 White
BaCl2
NaOH No
Ba2+ + SO42- = BaSO4
little Cu2+
CuSO4 + 4NH3·H2O = [Cu(NH3)4]SO4 + 4H2O Cu2+ + 4NH3 = [Cu(NH3)4]2+
§1. Basic Concepts
[Co(NH3)5H2O]Cl3 [Co(NH3)5Cl]Cl2
[CoCl2(H2O)2]
[Co(H2O)6]Cl2
§1. Basic Concepts
Coordinate covalent bond
A• + B•
A •• B
ຫໍສະໝຸດ Baidu
A + •• B
A •• B
A covalent bond in which both electrons
come from one of the atoms is called coordinate covalent bond(配位共价键).
H+ + :NH3
H
+
::
H :N: H
H
§1. Basic Concepts
Experiment NH3·H2O
NH3·H2O
CuSO4
Blue
Dark blue solution
NH3
coordinate covalent bonds.
A coordination compound (or complex)(配位化合物) is
a compound consisting either of complex ion and ions
of opposite charge (e.g., the compound [Cu(NH3)4]SO4 of the complex ion Cu(NH3)42+ and SO42- ion) or of a neutral complex species (e.g., [Fe(CO)5]).
are electron-pair donors.
The electron-pair donating atom in a ligand is called
ligating atom(配位原子). [Cu(NH3)4]2+，[Zn(OH)4]2-
，Fe(CO)5。
Why ?
:C. . + :O..:
A cation in which the positive charge is far removed from an electron pair that could be donated can function as a ligand. An example is the pyrazinium ion:
A complex ion (molecule)(配离子或配
位分子) (e.g., [Cu(NH3)4]2+,
NH3 2+
[Pt(NH3)2Cl2]) is a cation (or an atom) with anion or neutral
H3N Cu NH3
molecules attached to it through