Title: A Very Brief Introduction to Boron Chemistry
1A Very Brief Introduction to Boron Chemistry
- Kristina Orosz
- Nov. 5, 2004
2Uses of Boron
- Borosilicate glass-pyrex
- Detergents
- Flame retardants
- Ceramics
- Pyrotechnics
- Used in production of impact resistant steels
- Control rods in nuclear reactors
3Common Bonds in Boranes
- 2c-2e- B-H
- 3c-2e- B-H-B
- 2c-2e- B-B
- 3c-2e- B-B-B
4Diborane B2H6
5Wade, K. Electron Deficient Compounds. London
Nelson, 1971. 30.
6Tetraborane B4H10
7Huheey, J. E. Keiter, E. A. Keiter, R. L.
Inorganic Chemistry principles of structure and
reactivity, 4th ed. New York HarperCollins
College Publisher, 1993. 795.
8Elemental Forms of Boron
b-rhombohedral, B12(B12)12, (B12)(B12)(B60)
a- rhombohdral
9Boron Deltahedra Parent Clusters
10Boron Hydrides
11Huheey, J. E. Keiter, E. A. Keiter, R. L.
Inorganic Chemistry principles of structure and
reactivity, 4th ed. New York HarperCollins
College Publishing, 1993. 799.
12Wades Rules
- n number of B atoms in parent closo-deltahedron
- Always n1 bonding e- pairs and n1 bonding MOs
- nido has n-1 vertices
- arachno has n-2 vertices
- hypho has n-3 vertices
13- Find total available bonding e-s
- Each B-H unit gives 2 e-s
- Each additional H gives 1 e-
- Overall charge
- Find parent closo-deltahedron
- n1 bonding e- pairs
- Is it closo, nido, arachno, hypho?
- Lose highest connectivity B first then lose
adjacent sites - Determine number of remaining hydrogen atoms
- Each vertex has a H
- sew up hole with H atoms
- Bridging H atoms
- Low connectivity B atoms can get another 2c-2e-
B-H bond - Try to keep it as symmetrical as possible
14(No Transcript)
15CarboranesC2B10H12
ortho
meta or neo
para
16Boron Neutron Capture Therapy (BNCT)
- 10B has large cross-section for neutron capture
- 10B ? a 7Li
- Products can kill cells
- Cancer treatment
- Cages - need high 10B in cell
17References
- Dreiss, Matthias, ed., and Heinrich Nöth, ed.
Molecular Clusters of the Main Group Elements.
Weinheim Wiley-VCH, 2004. 95-125. - Housecroft, Catherine E. Boranes and
Metallaboranes structure, bonding, and
reactivity. 2nd ed. New York Ellis Horwood,
1994. 1-20, 93-116. - Housecroft, Catherine E., and Alan G. Sharpe.
Inorganic Chemistry. New York Pearson Education
Limited, 2001. 245-279. - Huheey, James E., Ellen A. Keiter, and Richard L.
Keiter. Inorganic Chemistry principles of
structure and reactivity. New York HarperCollins
College Publishers, 1993. 789-801. - Wade, Kenneth. Electron Deficient Compounds.
London Nelson, 1971. 1-61.