Correct order of Lewis base Character ?

Options

A. `NF_(3)ltNCl_(3)ltNBr_(3)ltNI_(3)`
B. `NF_(3)ltNCl_(3)gtNBr_(3)ltNI_(3)`
C. `NF_(3)gtNCl_(3)gtNBr_(3)gtNI_(3)`
D. `NF_(3)gtNI_(3)gtNCI_(3)gtNBr_(3)`

Explanation

To determine the correct order of Lewis base character for nitrogen halides (NX3), we need to analyze the influence of electronegativity on the Lewis base character of these compounds. The Lewis base character is determined by the ability of the compound to donate a lone pair of electrons.

### Step-by-step Solution:

1. **Identify the Nitrogen Halides**: The nitrogen halides we are considering are:
- Nitrogen trifluoride (NF3)
- Nitrogen trichloride (NCl3)
- Nitrogen tribromide (NBr3)
- Nitrogen triiodide (NI3)

2. **Understand Lewis Base Character**: A Lewis base is a substance that can donate a pair of electrons. The ability of a nitrogen halide to act as a Lewis base is influenced by the electronegativity of the halogen atoms attached to nitrogen.

3. **Electronegativity of Halogens**: The electronegativity of the halogens decreases in the following order:
- Fluorine (F) > Chlorine (Cl) > Bromine (Br) > Iodine (I)

4. **Effect of Electronegativity on Lewis Base Character**:
- Higher electronegativity of the halogen means that it will attract the electron density away from nitrogen, making it less willing to donate its lone pair.
- Conversely, a lower electronegativity means that the nitrogen will be more willing to donate its lone pair.

5. **Order of Lewis Base Character**:
- Since fluorine is the most electronegative, NF3 will have the least Lewis base character.
- Following that, NCl3 will have a slightly higher Lewis base character than NF3.
- NBr3 will have more Lewis base character than NCl3.
- Finally, NI3, with iodine being the least electronegative, will have the highest Lewis base character.

6. **Final Order**: Therefore, the correct order of Lewis base character for nitrogen halides is:
- NI3 > NBr3 > NCl3 > NF3