Comments like "Pentaborane is 2,000 times more deadly than cyanide" are just nonsense. You'd just about get away with sniffing Pentaborane (as long as it didn't explode in your face), but I wouldn't like to try that again with cyanide. Did it once, nearly got killed.
There are some major handling problems with it though -the wiki entry should give some pointers
https://secure.wikimedia.org/wikiped...ki/Pentaborane
Not something to be sitting on top of.
I'll always regret not taking up the offer I was given in 1985 of buying part of Russia's excess stocks after they binned their boron fuels program. An Academician from Perm called me out of the blue with a business proposal, but the political logistics at the time simply would have been too difficult. They had a wide range of different borane chemicals available - more than Callery in the USA were offering
There would probably have been more success with an organoborane (e.g. Methylborane) dissolved in a synthetic hydrocarbon, but they don't seem to have explored that very far.