Question

The IUPAC name of the complex [Pt(NH$_{3}$)$_{2}$Cl(NO$_{2}$)] is:

• A. Diamminochloronitroplatinum(II)
• B. Diamminochloronitrito-N-platinum(II)
• C. Diamminechloronitrito-N-platinum(II)
• D. Diamminechloronitro-N-platinum(II)

Hint:

“Amine” has double m (ammine). Ligands are always written in alphabetical order, not by number.

Answer 1

The Correct Option is C

Step 1: Identify all the ligands.
The complex $[Pt(NH_3)_2Cl(NO_2)]$ has two ammine groups $NH_3$, one chloro group $Cl^-$, and one $NO_2^-$ group. We must name each one correctly.

Step 2: Name the $NO_2^-$ ligand carefully.
The $NO_2^-$ ion can bind through nitrogen or through oxygen. When it binds through nitrogen, the modern name is nitrito-N. So we use nitrito-N here.

Step 3: Use the correct spelling for ammine and chloro.
The $NH_3$ ligand is written as ammine with a double m, and two of them give diammine. The $Cl^-$ ligand is written as chloro.

Step 4: Find the oxidation state of platinum.
Ammine is neutral, chloro is $-1$, and nitrito is $-1$. For a neutral complex: \[ x + 0 + 0 - 1 - 1 = 0 \Rightarrow x = +2 \] So platinum is in the $+2$ state.

Step 5: Arrange ligands in alphabetical order.
Ordering by first letter gives ammine, then chloro, then nitrito-N. So the ligand part reads diamminechloronitrito-N.

Step 6: Build the full name.
Adding the metal and its oxidation state in roman numerals gives the complete name.
\[ \boxed{\text{Diamminechloronitrito-N-platinum(II)}} \]