Nomenclature
CAS number: 18433-84-6
Dihydropentaborane(9); pentaboron undecahydride.
B
5H
11; mol wt 65.14.
B 82.98%, H 17.02%.
Description and references
Prepd from diborane: Burg, Schlesinger, J. Am. Chem. Soc. 55, 4009 (1933).
Properties
Liquid. mp -123°. bp 63°; bp53 0°. Unstable. When heated or allowed to stand for long periods
of time, it produces diborane, tetraborane, hydrogen, pentaborane,
decaborane and brown nonvolatile liqs and solids. Ignites spontaneously
in air. Hydrolyzes in water to boric acid and hydrogen. Reacts with
ammonia to form a tetraammoniate.