What is the IUPAC name of [Pt(NH_3)_2CI(NO_2)]?

The correct answer is Option (1) → Diamminechloridonitrito-N-platinum(II)

The correct IUPAC name of the coordination compound \([Pt(NH_3)_2Cl(NO_2)]\) is: Diamminechloridonitrito-N-platinum(II).

Here is the detailed reasoning behind this naming:

[Pt(NH₃)₂Cl(NO₂)]

The central metal is Platinum (Pt).

NH₃ (ammine) is a neutral ligand, and there are two of them, hence "diammine."

Cl⁻ is a negatively charged ligand and is named as chlorido.

NO₂⁻ can coordinate to the metal in two ways:

Through the nitrogen atom (nitrito-N) or

Through the oxygen atom (nitrito-O).

In this case, the nitrito ligand is bound through the nitrogen atom, so it is named nitrito-N.

Oxidation state of Platinum (Pt)

The ligands are NH₃ (neutral), Cl⁻ (charge = -1), and NO₂⁻ (charge = -1).

The overall charge of the complex is 0.

Let the oxidation state of platinum be \( x \).

\(x + 2(0) + (-1) + (-1) = 0 \implies x = +2\)

Thus, the oxidation state of platinum is +2, indicated by (II).

The name is constructed as Diamminechloridonitrito-N-platinum(II).

"Diammine" for the two NH₃ ligands.

"Chlorido" for the chloride ion (Cl⁻).

"Nitrito-N" for the nitrito ligand coordinated through nitrogen.

"Platinum(II)" for the metal and its oxidation state.

Incorrect Options:

Diamminechloridenitrito-N-platinum(III): Incorrect because the oxidation state is not +3, it's +2.

Diamminechloridonitrito-O-platinum(II): Incorrect because in this complex, the nitrito ligand is coordinated through nitrogen (N), not oxygen (O).

Diammonia chloridonitrito-N-platinum(II): Incorrect because "ammonia" is not the correct term for NH₃ in coordination chemistry; it should be "ammine."

Thus, the correct IUPAC name is **Diamminechloridonitrito-N-platinum(II)