B5H9 PENTABORANE

Boranes are usually named by indicating the number of B atoms with a latin prefix and the number of H atoms by an arabic number in parentheses, e.g. B5H9, pentaborane(9) B5H11, pentaboranefl 1). Names for anions end in ate rather than ane and specify both the number of H and B atoms and the charge, e.g. BsHs" octahydropentaboratefl—). Further information can be provided by the optional inclusion of the italicized descriptors closo-, nido-, arachno-, hypho- and conjuncto-, e.g. ... 

B5H9 PENTABORANE -48.121 5.6949E-01 -3.3162E-04 5.6690E-08 7.8563E-12 298 1500 gas... 

Subsequently a number of other boranes have been discovered, so that today there are no less than 14 that are well-characterized chemically, and for most the structures are well-defined. A convenient nomenclature for the boranes specifies the number of hydrogen atoms with an arabic number in parentheses. For example B5H9 pentaborane(9), and B5Hn pentabor-ane(ll). The hydrogen number may be omitted where only one compound with the number of boron atoms in question is known, viz., B4H10 tetra-borane. A list of the better characterized boranes is given in Table 8-1. 

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