A: `AI_(2)(CH_(3))_(6)` is a dimeric compound and has Similar structure to diborane. R: `AI_(2)(CH_(3))_(6)` in a sigma bonded complex

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (1)
B. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark (2).
C. ) If Assertion is true statement but Reason is false, then mark (3).
D. If both Assertion and Reason are false statements, then mark (4)

Answer

To solve the question regarding the compound \( Al_2(CH_3)_6 \) and its properties, we will break down the assertion and reasoning step by step.

### Step 1: Understanding the Assertion
The assertion states that \( Al_2(CH_3)_6 \) is a dimeric compound and has a structure similar to diborane.

- **Dimeric Compound**: A dimeric compound consists of two identical or similar units. In this case, \( Al_2(CH_3)_6 \) can be viewed as a dimer formed from the monomer \( Al(CH_3)_3 \).
- **Similar Structure to Diborane**: Diborane (\( B_2H_6 \)) has a unique structure characterized by the presence of three-center two-electron bonds (often referred to as "banana bonds"). This structure allows for the bonding of hydrogen atoms to two boron atoms simultaneously.

### Step 2: Analyzing the Reason
The reason states that \( Al_2(CH_3)_6 \) is a sigma-bonded complex.

- **Sigma Bonding**: Sigma bonds are the strongest type of covalent chemical bond, formed by the head-on overlap of atomic orbitals. In \( Al_2(CH_3)_6 \), the aluminum atoms are likely to form sigma bonds with the methyl groups (\( CH_3 \)).
- **Complex Formation**: The presence of sigma bonds indicates that the structure is stable and that the bonding involves overlapping orbitals.

### Step 3: Comparing the Assertion and Reason
- **Assertion Validity**: The assertion is correct as \( Al_2(CH_3)_6 \) is indeed a dimeric compound and can exhibit a structure similar to diborane due to the presence of three-center two-electron bonds.
- **Reason Validity**: While the reason is also correct in stating that \( Al_2(CH_3)_6 \) is a sigma-bonded complex, it does not fully explain the assertion regarding the similarity to diborane. The assertion focuses on the dimeric nature and structural similarity, while the reason only addresses bonding type.

### Conclusion
Both the assertion and the reason are true, but the reason does not provide a correct explanation for the assertion. Thus, the correct answer is that both assertion and reason are true, but the reason is not a correct explanation of the assertion.

### Final Answer
- **Assertion (A)**: True
- **Reason (R)**: True, but not a correct explanation of (A)