Chapter 21 - Transition Metals and Coordination Chemistry

Iron

________ plays a central role in almost all living cells.

Geometric isomerism

________**: Ligands assume different relative positions in the coordination sphere; examples are cis and trans isomers.

Transition metal ions

________ characteristically form coordination compounds, which are usually colored and often paramagnetic.

chromium configuration

The ________ occurs because the energies of the 3d and 4d orbitals are very similar for the first- row transition elements.

Impure product

________ (􏰵90 % iron) is called pig iron.

Steel

________ is manufactured by oxidizing the impurities in pig iron.

identical bonds

Stereoisomerism**: Isomers have ________ but different spatial arrangements.

metal ion

The interaction between a(n) ________ and a ligand can be viewed as a Lewis acid- base reaction with the ligand donating a lone pair of electrons to an empty orbital of the ________ to form a coordinate covalent bond.

Oxidation

________ is carried out in various ways, but the two most common are the open- hearth process and the basic oxygen process.

Niobium

________ and molybdenum are important alloying materials for certain types of steel.

Silver

________ is the best conductor of heat and electric current.

large molecule

A protein is a(n) ________ assembled from amino acids, which have the general structure in which R represents various groups.

isomerism

Linkage ________**: The point of attachment of one or more ligands varies.

ores

The minerals in ________ are often converted to oxides (roasting) before being reduced to metal (smelting)

high resistance

Tantalum, which has a(n) ________ to attack by body fluids, is often used for the replacement of bones.

crystal field model

The ________ also applies to square planar and linear complexes.

Coordination compounds

________ have been known since about 1700, but their true nature was not understood until the 1890s when a young Swiss chemist named Alfred Werner proposed that transition metal ions have two types of valence.

Cyanide

________ coordinates strongly to cytochrome oxidase, an aniron- containing cytochrome enzyme that catalyzes the oxidation- reduction reactions of certain cytochrome.

Hemoglobin

________ dramatically demonstrates how sensitive the function of a biomolecule is to its structure.

transition metals

The ________ behave as typical metals, possessing metallic luster and relatively high electrical and thermal conductivities.

Ligand

________**: a neutral molecule or ion having a lone electron pair that can be used to form a bond to a metal ion.

photon of light

A given ________ can be absorbed by a molecule only if the wavelength of the light provides exactly the energy needed by the molecule.

principal source of energy

In mammals, the ________ comes from the oxidation of carbohydrates, proteins, and fats.

transition metal ion

The cations are often complexions, species where the ________ is surrounded by a certain number of ligands.

isomerism

Optical ________**: Molecules with non- superimposable mirror images rotate plane- polarized light in opposite directions.

metal ion

Some ligands have more than one atom with a lone electron pair that can be used to bond to a(n) ________.

crystal field model

The ________ focuses on the energies of the d orbitals.

transition metal ions

In ________, the 3d orbitals are lower in energy than the 4s orbitals.

metal ion

For example, ________ complexes are used in humans for the transport and storage of oxygen, as electron- transfer agents, as catalysts, and as drugs.

metal ion

A ligand that can form one bond to a(n) ________ is called a monodentate ligand.

transition metal ion

Coordination compound**: A(n) ________ with its attached ligands.