Chapter 9, Problem 9C.1AST

(a)

Interpretation Introduction

Interpretation:

The name of the complex $\left[\text{Fe}\left(\text{OH}\right){\left({\text{OH}}_{\text{2}}\right)}_{\text{5}}\right]{\text{Cl}}_{\text{2}}$ has to be given.

Concept Introduction:

Rules for naming the complex:

• Name the ligands first, and then the metal atom or ion. A Roman numeral in parentheses denotes the oxidation number of the central metal ion.
• Neutral ligands, such as ${\text{H}}_{\text{2}}{\text{NCH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{NH}}_{\text{2}}$ (ethylenediamine) have the same name as the molecule, except for ${\text{H}}_{\text{2}}\text{O}$ (aqua), ${\text{NH}}_{\text{3}}$ (ammine), $\text{CO}$ (carbonyl), and $\text{NO}$ (nitrosyl).
• Anionic ligands end in -o; for anions that end in -ide (such as chloride), -ate (such as sulfate), and -ite (such as nitrite), change the endings as -ide, -ido, ate, -ato, ite, -ito.

Examples: chlorido, sulfato, and nitrito.

• Greek prefixes indicate the number of each type of ligand in the complex ion:2-di, 3-tri, 4-tetra, 5-penta, 6-hexa.
• If the ligand already contains a Greek prefix (such as the diinethylenediamine) or if it is polydentate (able to attach at more than one binding site simultaneously), then the following prefixes are used instead 2-bis, 3-tris, 4-tetrakis.
• Ligands are named in alphabetical order, ignoring any Greek prefix.
• If there is an uncertainty in identifying which atom is linked to the metal atom, then k E is added to the name in parentheses, where E denotes the connecting atom (and $\text{Κ}$ is kappa).
• If the complex has an overall negative charge (an anionic complex), the suffix -ate is added to the stem of the metal’s name. If the symbol of the metal originates from a Latin name, then the Latin stem is used followed by the oxidation number of the metal in Roman numerals.
• The name of a coordination compound (as distinct from a complex cation or anion) is built in the same way as that of a simple compound, with the cation named before the anion.

(b)

Interpretation Introduction

Interpretation:

The chemical formula of the complex Potassiumdiaquabis (oxalato) chromate (II) has to be given.

Concept Introduction:

Rules for writing the formula of the complex:

• Write the chemical symbol of the central atom (usually a metal atom) first, followed by symbols for the ligands, then enclose the entire collection of symbols between square brackets and add the overall charge.
• Write the chemical symbols of ligands in alphabetical order, when different ligands contain the same element, those denoted by a single letter (e.g., O) take priority over symbols represented by two or more letters (e.g., OH).  If a particular point needs to be emphasized, then the order may be varied.  For example water as a ligand is denoted OH2, to emphasize that the O links to the metal atom.
• To avoid any ambiguity, the linking atom can be underlined.