Which of the following do not have tendency to act as ligands during complex formation?

Options

A. `BiH_(3)`
B. `PH_(3)`
C. `AsH_(3)`
D. `SbH_(3)`

Answer

To solve the question of which of the following compounds do not have the tendency to act as ligands during complex formation, we will analyze the given options based on their chemical properties. The options provided are:

1. BiH3 (Bismuth trihydride)
2. Ph3 (Triphenylphosphine)
3. AsH3 (Arsenic trihydride)
4. SbH3 (Antimony trihydride)

### Step-by-Step Solution:

**Step 1: Identify the Group of Elements**
- All the options given are hydrides of Group 15 elements (Nitrogen group). This includes Bi (Bismuth), As (Arsenic), Sb (Antimony), and P (Phosphorus).

**Step 2: Understand the Concept of Ligands**
- Ligands are species that can donate a pair of electrons to a metal center to form a coordinate bond. The ability of a compound to act as a ligand is often related to its basicity and the availability of lone pairs of electrons.

**Step 3: Analyze the Basicity of the Hydrides**
- The basicity of Group 15 hydrides generally decreases down the group. The trend in basicity is:
- NH3 > PH3 > AsH3 > SbH3 > BiH3
- This means that NH3 (Ammonia) is the most basic and can act as a strong ligand, while BiH3 and SbH3 are the least basic.

**Step 4: Determine the Tendency to Act as Ligands**
- Since ligands must have the ability to donate lone pairs of electrons, we can conclude that:
- NH3 and PH3 can act as ligands due to their higher basicity.
- AsH3 can also act as a ligand, but to a lesser extent.
- BiH3 and SbH3, being the least basic, have a lower tendency to donate lone pairs of electrons and thus do not act as ligands.

**Step 5: Conclusion**
- Based on the analysis, BiH3 and SbH3 do not have the tendency to act as ligands during complex formation.

### Final Answer:
BiH3 and SbH3 do not have a tendency to act as ligands during complex formation.

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