Question

The correct IUPAC name of $[\text{PtBr}_2(\text{PMe}_3)_2]$ is:

• A. bis(trimethylphosphine)dibromoplatinum(II)
• B. bis[bromo(trimethylphosphine)]platinum(II)
• C. dibromobis(trimethylphosphine)platinum(II)
• D. dibromodi(trimethylphosphine)platinum(II)

Answer 1

The Correct Option is C

To determine the correct IUPAC name for the complex $[\text{PtBr}_2(\text{PMe}_3)_2]$, we need to follow the rules for naming coordination compounds:

1. Identify the Ligands: In the given complex, there are two types of ligands:
   • Two bromides (Br^-), which are anionic ligands.
   • Two trimethylphosphine (PMe₃) groups, which are neutral ligands.
2. Name the Ligands in Alphabetical Order: The ligands should be named in alphabetical order, regardless of their charge. Thus, we first mention "bromo" followed by "trimethylphosphine." The ligand name for PMe₃ is simply "trimethylphosphine."
3. Use Multiplicative Prefixes: Since there are two of each ligand, the prefix "di" is used for both:
   • "dibromo" for the two bromide ligands.
   • "bis(trimethylphosphine)" for the two trimethylphosphine ligands. We use "bis" because "trimethylphosphine" is already a complex ligand name.
4. Name the Metal and its Oxidation State: The central metal atom is platinum (Pt). Its oxidation state is given in Roman numerals. For this complex, the oxidation state of platinum is +2.

How do we determine this? The complex is neutral overall. Each bromide contributes -1 to the charge, and the PMe₃ groups are neutral: \([\text{Pt} + 2(-1) + 2(0) = 0 \Rightarrow \text{Pt} = +2]\)

1. Assemble the Name: Combining these names with the correct order and terminology gives us "dibromobis(trimethylphosphine)platinum(II)."

Thus, the correct IUPAC name for $[\text{PtBr}_2(\text{PMe}_3)_2]$ is dibromobis(trimethylphosphine)platinum(II), which matches option three.

Answer 2

The correct IUPAC name of $[\text{PtBr}_2(\text{PMe}_3)_2]$ is: Dibromo bis(trimethylphosphine) platinum (II)