Tetraborane, pyrolysis

Mass spectrometric investigation of the pyrolysis of tetraborane by Stafford et al." gave evidence for the intermediate B4H8. As in similar work under their experimental conditions the influence of heterogeneous catalysis might be dominant. 

Heating B2H6 above 100°C leads to pyrolysis and generates a variety of more complex boranes of which tetraborane(lO) B4H10 and decabomae(14) B10H14 are the most stable. Other reactions can lead to anionic species, such as the icosahedral dodecahydrodecaborate (2-) [BI2H12]2-, prepared at 180°C ... 

The relative proportions of the products are markedly dependent on the conditions. Up to 90% conversion to Bi H o may be realized in a hot-cold reactor in which an inner cylindrical surface is heated to 100°C while the outer surface is maintained at -80 C to trap out the tetraborane as it is formed (179). Stock and Mathing had earlier shown that pyrolysis at higher temperatures (180°C) leads to B5H11 as a major product, whereas at still higher temperatures (250-300°C) B5H9 predominates (306). More recently Owen... 

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