Question

Write IUPAC names of the following coordination compounds:
(i) \( [Ag(NH_3)_2][Ag(CN)_2] \)
(ii) \( K_3[Fe(C_2O_4)_3] \)

Hint:

When the metal is in an anionic complex, its name must end with the suffix '-ate' (e.g., Ferrate, Argentate, Cuprate, Plumbate).

Answer 1

Step 1: Understanding the Concept:
IUPAC naming follows a specific order: Cation is named first, then the anion. Within a complex ion, ligands are named alphabetically followed by the metal and its oxidation state in Roman numerals.
Step 2: Key Formula or Approach:
Calculate oxidation states:
(i) Both Ag atoms are in +1 state. Cationic part: \( [Ag(NH_3)_2]^+ \), Anionic part: \( [Ag(CN)_2]^- \).
(ii) \( 3(+1) + x + 3(-2) = 0 \Rightarrow x = +3 \).
Step 2: Detailed Explanation:
(i) \( [Ag(NH_3)_2][Ag(CN)_2] \):
The cationic complex is \( [Ag(NH_3)_2]^+ \). Ligand: ammine (2 \(\rightarrow\) diammine). Metal: Silver. Name: Diamminesilver(I).
The anionic complex is \( [Ag(CN)_2]^- \). Ligand: cyano (2 \(\rightarrow\) dicyano). Metal: Argentum + 'ate' suffix \(\rightarrow\) argentate. Name: Dicyanoargentate(I).
Full Name: Diamminesilver(I) dicyanoargentate(I).
(ii) \( K_3[Fe(C_2O_4)_3] \):
Cation: Potassium.
Anion: \( [Fe(C_2O_4)_3]^{3-} \). Ligand: oxalate (3 \(\rightarrow\) trioxalato). Metal: Iron + 'ate' suffix \(\rightarrow\) ferrate.
Full Name: Potassium trioxalatoferrate(III).
Step 3: Final Answer:
(i) Diamminesilver(I) dicyanoargentate(I)
(ii) Potassium trioxalatoferrate(III)