Question

Which of the following is the correct IUPAC name for the \([Pt(NH_3)_2Cl(NO_2)]\) coordination compound?

• A. Diamminechloridonitrito-N-platinum(II)
• B. Diamminechloridonitrido-N-platinum(III)
• C. Diamminechloridonitrito-N-platinate(II)
• D. Diamminechloridenitrido-N-platinum(II)

Hint:

The complex is neutral, so Pt is +2 and the metal name stays platinum. NO₂ is nitrito, not nitrido.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
IUPAC naming lists ligands in alphabetical order, then the metal with its oxidation state in brackets. A neutral or cationic complex keeps the plain metal name. An anionic complex uses the "-ate" ending.

Step 2: Ligands:
\(NH_3\) is ammine, and there are two, so "diammine". \(Cl^{-}\) is chlorido. \(NO_2^{-}\) bonded through nitrogen is named "nitrito-N" in the style used in this question. Alphabetical order of ammine, chlorido and nitrito gives the order a, c, n.

Step 3: Oxidation state of platinum:
The complex is neutral. Let the oxidation state be \(x\). \[ x + 2(0) + (-1) + (-1) = 0 \Rightarrow x = +2 \] So it is platinum(II).

Step 4: Metal ending:
The complex has no net charge, so the metal name is "platinum", not "platinate". Option 3 is wrong for this reason.

Step 5: Other options:
Option 2 has the oxidation state +3, which is wrong. Option 4 uses "nitrido", which means \(N^{3-}\), and not the \(NO_2^{-}\) ligand.

Final Answer:
The name is diamminechloridonitrito-N-platinum(II). \[ \boxed{\text{Option 1}} \]