Bài soạn Chapter 24 Transition Metals and Coordination Compounds

Chapter 24
Transition
Metals and
Coordination
Compounds
2011, NKMB Co., Ltd.
Chemistry, Julia Burdge, 2
st
Ed.
McGraw Hill.
Mr. Truong Minh Chien ;
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2
Gemstones
•
the colors of rubies and emeralds are both due
to the presence of Cr
3+
ions – the difference lies
in the crystal hosting the ion
Some Al
3+
ions
in Al
2
O
3
are
replaced by
Cr
3+

Some Al
3+
ions
in
Be
3
Al
2
(SiO
3
)
6

are replaced by
Cr
3+
Chemistry, Julia Burdge, 2
nd
e., McGraw Hill.
3
Properties and Electron Configuration of
Transition Metals
•
the properties of the transition metals are similar to each
other

and very different to the properties of the main group metals

high melting points, high densities, moderate to very hard, and
very good electrical conductors

•
in general, the transition metals have two valence
electrons – we are filling the d orbitals in the shell below
the valence

Group 1B and some others have 1 valence electron due to
“promotion” of an electron into the d sublevel to fill it

form ions by losing the ns electrons first, then the (n – 1)d
Chemistry, Julia Burdge, 2
nd
e., McGraw Hill.
4
Atomic Size
•
the atomic radii of all
the transition metals
are very similar

small increase in size
down a column
Chemistry, Julia Burdge, 2
nd
e., McGraw Hill.
5
Ionization Energy
•
the first ionization
energy of the
transition metals

slowly increases
across a series
•
third transition series
slightly higher 1
st
IE

trend opposite to
main group elements
Chemistry, Julia Burdge, 2
nd
e., McGraw Hill.
6
Electronegativity
•
the electronegativity of
the transition metals
slowly increases across a
series

except for last element in
the series
•
electronegativity
slightly increases down
the column

trend opposite to main
group elements

Chemistry, Julia Burdge, 2
nd
e., McGraw Hill.
7
Oxidation States
•
often exhibit multiple oxidation states
•
vary by 1
•
highest oxidation state is group number for 3B to 7B
Chemistry, Julia Burdge, 2
nd
e., McGraw Hill.
8
Coordination Compounds
•
when a complex ion combines with counterions to make
a neutral compound it is called a coordination
compound
•
the primary valence is the oxidation number of the
metal
•
the secondary valence is the number of ligands bonded
to the metal

coordination number
•
coordination number range from 2 to 12, with the most

common being 6 and 4
CoCl
3
⋅6H
2
O = [Co(H
2
O)
6
]Cl
3
Chemistry, Julia Burdge, 2
nd
e., McGraw Hill.
9
Coordination Compound
Chemistry, Julia Burdge, 2
nd
e., McGraw Hill.
10
Complex Ion Formation
•
complex ion formation is a type of Lewis acid-
base reaction
•
a bond that forms when the pair of electrons is
donated by one atom is called a coordinate
covalent bond
Chemistry, Julia Burdge, 2
nd

e., McGraw Hill.
11
Ligands with Extra Teeth
•
some ligands can form more than one
coordinate covalent bond with the metal atom

lone pairs on different atoms that are separate enough
so that both can reach the metal
•
chelate is a complex ion containing a
multidentate ligand

ligand is called the chelating agent
Chemistry, Julia Burdge, 2
nd
e., McGraw Hill.
12
Chemistry, Julia Burdge, 2
nd
e., McGraw Hill.
13
EDTA
a Polydentate Ligand
Chemistry, Julia Burdge, 2
nd
e., McGraw Hill.
14
Complex Ions with Polydentate Ligands
Chemistry, Julia Burdge, 2

nd
e., McGraw Hill.
15
Geometries in Complex Ions
Chemistry, Julia Burdge, 2
nd
e., McGraw Hill.
16
Common Ligands
Chemistry, Julia Burdge, 2
nd
e., McGraw Hill.
17
phenanthroline
H
2
N
NH
2
ethylene diamine
O
O
-
O
-
O
oxalate
Chemistry, Julia Burdge, 2
nd
e., McGraw Hill.

[Fe(en)(NH
3
)
4
]Cl
3
•
Fe is +3
•
3 moles of AgCl would form
Fe
N
N
NH
3
NH
3
NH
3
NH
3
H
2
C
H
2
C
H
H
+3

Chemistry, Julia Burdge, 2
nd
e., McGraw Hill.