Chemistry - A Molecular Science

Chapter 14 Inorganic Chemistry

14.5 Transition Metals as Catalysts 14.0

INTRODUCTION In Chapter 13 we discussed organic chemistr

y, which is based on the chemistry of carbon.

That leaves the chemistry of over a hundred

elements to be broadly characterized as

inorganic chemistry

. Many of these elements have a very rich chemistry of their own, but

we cannot begin to do justice to all of inor

ganic chemistry in this last chapter. We,

therefore, take a segment of these elements, the

transition elements

, and present a very

small portion of their chemistry here. As we sh

all see in this chapter, transition elements

are vital to the function of living organisms and to the treatment of disease; they also serve as catalysts and electronic and magnetic materials.

The

transition elements

are the B-group elements that fall between Group 2A and

Group 3A on the periodic table. They are usually characterized as having partially filled

(^) d
sublevels. They are all metals and are frequently referred to as the
transition metals
.
Often they are found as
complexes
in which the metal is bound to several molecules or
ions that we call
ligands

. Ligands are Lewis bases, and transition metal cations are Lewis

acids, so the metal ligand bond is a coordinate covalent bond. The compounds that transition metals form are frequently called

coordination compounds

.^
For example,

[Co(NH

) 36

][PtCl

] is a coordination compound that consists of 4

two

complex ions,

[Co(NH

) 36

2+]

and [PtCl

2-] 4

, which have ammonia molecules and chloride ions as ligands.

Many transition metal compounds are brightly colored, such as the deep blue color of a solution of solvated Cu

2+

ions, Cu(H

O) 2

2+ 6

. Transition metal compounds also have

interesting magnetic properties that are strongl

y influenced by the nature of the ligands

Chapter 14 Inorganic Chemistry attached to the metal, even though the unpaired electrons reside on the metal.

14.0 Introduction

14.5 Transition Metals as Catalysts

14.1 Ligands and Coordination

14.6 Transition Metals as Electronic and Magnetic Materials

14.2 The d Orbitals and Ligand Fields

14.7 Chapter Summary and Objectives

14.3 Isomers

14.8 Exercises

14.4 Metals in Biology

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