Health & Environmental Research Online (HERO)


Print Feedback Export to File
8713811 
Journal Article 
Early Carboranes and Their Structural Legacy 
Williams, RE 
1994 
Advances in Organometallic Chemistry 
36 
1-55 
English 
This chapter focuses on the molecules consisting of boron, carbon, and hydrogen––that is, compounds belonging to the polyborane, carborane, and carbocation continuum. It discusses the entire range of closo-carboranes. Carboranes are mixed hydrides of carbon and boron in which atoms of both elements feature in the electron deficient polyhedral molecular skeleton. The majority of the structural patterns, the emphasis of this chapter, became evident from structural studies on the more illuminating smaller closo-carboranes while the overwhelming majority of carborane synthetic chemistry was subsequently derived from reactions involving the more important icosahedral closo-carboranes. On the basis of the 11B nuclear magnetic resonance (NMR) spectra, this chapter concludes that the structures of these compounds must be three-dimensional, nonclassical, and deltahedral (with the carbons occupying low coordination vertices and nonadjacent in the most stable isomers) rather than two-dimensional, classical, and more or less “flat” as benzene or cyclohexane. 1994 Academic Press Inc.