Chapter 23, Problem 23.45P

(a)

Interpretation Introduction

Interpretation:

For the given complex the systematic name has to be given.

  ${\text{[Ni(H}}_{\text{2}}{\text{O)}}_{\text{6}}{\text{]Cl}}_{\text{2}}$

Concept introduction:

The set of rules for naming a coordination compound is:

1. 1. When naming a complex ion, the ligands are named before the metal ion.
2. 2. Write the names of the ligands in the following order: neutral, negative, positive.  If there are multiple ligands of the same charge type, they are named in alphabetical order.
3. 3. Multiple occurring monodentate ligands receive a prefix according to the number of occurrences: $\text{di-, tri-, tetra-, penta-, or hexa}\text{.}$  Polydentate ligands (e.g., ethylene diamine, oxalate) receive $\text{bis-, tris-, tetrakis-, etc}\text{.}$  Anions end in -ido.  This replaces the final “e” when the anion ends with “-ate” (e.g, sulfate becomes sulfato) and replaces “-ide” (cyanide becomes cyanido).
4. 4. Neutral ligands are given their usual name, with some exceptions: NH₃ becomes ammine; $H_{2}O$ becomes aqua or aquo;$CO$ becomes carbonyl; $\text{NO}$ becomes nitrosyl.
5. 5. Write the name of the central atom/ion. If the complex is an anion, the central atom’s name will end in -ate, and its Latin name will be used if available
6. 6. If the central atom’s oxidation state needs to be specified (when it is one of several possible, or zero), write it as a Roman numeral (or 0) in parentheses.
7. 7. End with “cation” or “anion” as separate words.

Explanation of Solution

The oxidation state of $Nimetal$ is found from the total charge on the ion

(${\text{+2 because two Cl}}^{\text{–}}\text{ charges equals –2}$) and the charge on ligands:

Charge on nickel $\text{= +2 – 6}\left(\text{0 charge on water}\right)\text{ = +2}$

Name nickel as nickel (II) to indicate oxidation state.  Ligands are six (hexa-) waters (aqua).  Put together with chloride anions to give hexaaquanickel (II) chloride.

(b)

Interpretation Introduction

Interpretation:

For the given complex the systematic name has to be given.

  ${\text{[Cr(en)}}_{\text{3}}{\text{](ClO}}_{\text{4}}{\text{)}}_{\text{3}}$

Concept introduction;

The set of rules for naming a coordination compound is:

1. 1. When naming a complex ion, the ligands are named before the metal ion.
2. 2. Write the names of the ligands in the following order: neutral, negative, positive.  If there are multiple ligands of the same charge type, they are named in alphabetical order.
3. 3. Multiple occurring monodentate ligands receive a prefix according to the number of occurrences: $\text{di-, tri-, tetra-, penta-, or hexa}\text{.}$  Polydentate ligands (e.g., ethylene diamine, oxalate) receive $\text{bis-, tris-, tetrakis-, etc}\text{.}$  Anions end in -ido.  This replaces the final “e” when the anion ends with “-ate” (e.g, sulfate becomes sulfato) and replaces “-ide” (cyanide becomes cyanido).
4. 4. Neutral ligands are given their usual name, with some exceptions: NH₃ becomes ammine; $H_{2}O$ becomes aqua or aquo;$CO$ becomes carbonyl; $\text{NO}$ becomes nitrosyl.
5. 5. Write the name of the central atom/ion. If the complex is an anion, the central atom’s name will end in -ate, and its Latin name will be used if available
6. 6. If the central atom’s oxidation state needs to be specified (when it is one of several possible, or zero), write it as a Roman numeral (or 0) in parentheses.
7. 7. End with “cation” or “anion” as separate words.

Explanation of Solution

The cation is ${\left[\text{Cr}{\left(\text{en}\right)}_{\text{3}}\right]}^{\text{n}}{}^{\text{+}}$ and the anion is ${\text{ClO}}^{\text{4}}{}^{\text{–}}\text{,}$ the perchlorate ion.  The charge on the cation is +3 to make a neutral salt in combination with the –3 charge of the three perchlorate ions.  The ligand is ethylene diamine, which has 0 charge.

The charge of the cation equals the charge on chromium ion, thus chromium (III) is included in the name.  The three ethylene diamine ligands, abbreviated $en$, are indicated by the prefix $\text{tris-}$ because the name of the ligand includes a numerical indicator, di-. The complete name is tris (ethylene diamine) chromium (III) perchlorate.

(c)

Interpretation Introduction

Interpretation:

For the given complex the systematic name has to be given.

  ${\text{K}}_{\text{4}}{\text{[Mn(CN)}}_{\text{6}}\text{]}$

Concept introduction;

The set of rules for naming a coordination compound is:

1. 1. When naming a complex ion, the ligands are named before the metal ion.
2. 2. Write the names of the ligands in the following order: neutral, negative, positive.  If there are multiple ligands of the same charge type, they are named in alphabetical order.
3. 3. Multiple occurring monodentate ligands receive a prefix according to the number of occurrences: $\text{di-, tri-, tetra-, penta-, or hexa}\text{.}$  Polydentate ligands (e.g., ethylene diamine, oxalate) receive $\text{bis-, tris-, tetrakis-, etc}\text{.}$  Anions end in -ido.  This replaces the final “e” when the anion ends with “-ate” (e.g, sulfate becomes sulfato) and replaces “-ide” (cyanide becomes cyanido).
4. 4. Neutral ligands are given their usual name, with some exceptions: NH₃ becomes ammine; $H_{2}O$ becomes aqua or aquo;$CO$ becomes carbonyl; $\text{NO}$ becomes nitrosyl.
5. 5. Write the name of the central atom/ion. If the complex is an anion, the central atom’s name will end in -ate, and its Latin name will be used if available
6. 6. If the central atom’s oxidation state needs to be specified (when it is one of several possible, or zero), write it as a Roman numeral (or 0) in parentheses.
7. 7. End with “cation” or “anion” as separate words.

Explanation of Solution

The cation is $K^{+}$ and the anion is ${\left[\text{Mn}{\left(\text{CN}\right)}_{\text{6}}\right]}^{\text{4}}{}^{\text{–}}\text{.}$  the charge of 4– is deduced from the four potassium +1 ions in the formula.  The oxidation state of $\text{Mn is –4 – }\left\{\text{6}\left(\text{–1}\right)\right\}\text{ = +2}\text{.}$ the name of ${\text{CN}}^{\text{–}}$ ligand is cyano and six ligands are represented by the prefix hexa-.  The name of manganese anion is manganite (II).  The -ate suffix on the complex ion is used to indicate that it is an anion.

The full name of compound is potassium hexacyanomanganate (II).