The correct statement about is :
- (A)All B - H - B angles are of .
- (B)The two bonds are not of same length.
- (C)Its fragment, , Behaves as a Lewis base.
- (D)Terminal bonds have less character when compared to bridging bonds.✓ Correct
Answer: (D)
Solution
Diborane () has a unique structure with two 3-center-2-electron (3c-2e) bridging B-H-B bonds and four terminal B-H bonds.
(A) Incorrect: The B-H-B bond angles are approximately 97°, not 120°.
(B) Incorrect: The two bridging B-H-B bonds are of the same length.
(C) Incorrect: is electron-deficient (only 6 electrons around B) and behaves as a Lewis acid, not a Lewis base.
(D) Correct: Terminal B-H bonds use sp³ hybrid orbitals with more s-character (25% s, 75% p), while bridging B-H bonds involve 3-center bonding with more p-character. Therefore, terminal B-H bonds have less p-character compared to bridging bonds.
The answer is (D).
(A) Incorrect: The B-H-B bond angles are approximately 97°, not 120°.
(B) Incorrect: The two bridging B-H-B bonds are of the same length.
(C) Incorrect: is electron-deficient (only 6 electrons around B) and behaves as a Lewis acid, not a Lewis base.
(D) Correct: Terminal B-H bonds use sp³ hybrid orbitals with more s-character (25% s, 75% p), while bridging B-H bonds involve 3-center bonding with more p-character. Therefore, terminal B-H bonds have less p-character compared to bridging bonds.
The answer is (D).
JEE Main · 2021 · 25 Feb 2021 · Shift 1 · Single correct option