The frameworks of such molecules may include atoms other than boron (e.g., carbon) and many of those with carbon (the carboranes
) form complexes with transition metals.
Bowen and Eastwood developed boron cage compounds (BCCs; boranes and carboranes
) as fillers for shielding and absorbing neutrons.
King et al., "The medicinal chemistry of carboranes," Coordination Chemistry Reviews, vol.
Rendina, "Boron in drug discovery: carboranes as unique pharmacophores in biologically active compounds," Chemical Reviews, vol.
"Over the past decade, we have seen an increasing interest in using carboranes in drug design," said Mark W.
"Carboranes are clusters of three elements - boron, carbon and hydrogen.
such as o- (1,2-), m- (1,7-), and p- (1,12-) [C.sub.2][B.sub.10][H.sub.12] have strong electron-withdrawing character, remarkable chemical and thermal stability, and high boron content.
Chapters discuss specific categories such as organometallics, carboranes
, carbocations, or transformations that proceed through transient hypercarbon species, with information on fundamental chemistry, including reactivity, selectivity, stereochemistry, and mechanistic factors.
For Paul Weiss of Pennsylvania State University in University Park and his colleagues, the "tablecloth" is a self-assembling layer of nanosized molecules called carboranes
. The layer of carboranes
changes the geometry and stability of the material beneath, the researchers report in the March issue of ACS Nano.
For describing the systems, analogy with benzene [pi]-bonding and aromaticity has been used, which in the case of carboranes
is expressed as [sigma]-aromaticity .
The study of the non-metal elements not only includes the traditional content, but also considers many areas previously unknown or partially defined, the boron hydrides, carboranes
, and metal-carboranes are compounds with unique structures and requiring molecular orbital descriptions to account for the bonding.
The thermal and oxidative properties of poly(siloxane)s are improved with carboranes
. Inserting acetylene into the backbones of the poly(carborane-siloxane) polymer improves its ability to retain mass at very high temperatures by crosslinking.