Discussion
The structure type and shape of the polyhedral (skeletal) framework of the carborane, Me2C2B10H10, respectively, are
Answer: B
The carborane is closo with an icosahedral framework.
Count the skeletal electron pairs with Wade's rules. Each B-H vertex contributes 2 skeletal electrons and each C-R vertex 3. For Me2C2B10H10, with 12 vertices:
\[ \begin{aligned} 10 \times 2 + 2 \times 3 &= 26\ \text{electrons} \\ &= 13\ \text{pairs} = n + 1 \end{aligned} \]
n + 1 pairs for n vertices is the closo count, a closed polyhedron with every vertex occupied, and the closed 12-vertex deltahedron is the icosahedron. This is the dimethyl derivative of the well-known icosahedral carborane C2B10H12.
A nido cluster would need n + 2 pairs. The dodecahedron (the 8-vertex deltahedron) is the closo shape for eight vertices, not twelve.
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development