Nomenclature
CAS number: 13762-51-1
Potassium tetrahydroborate.
BH
4K; mol wt 53.94.
B 20.04%, H 7.47%, K 72.48%.
KBH
4.
Description and references
Prepn: H. I. Schlesinger et al., J. Am. Chem. Soc. 75, 199 (1953). Commercial process: M. D. Banus et al., ibid. 76, 3848 (1954).
NMR relaxation study: T. Tsang, T. C. Farrar, J. Chem. Phys. 50, 3498 (1969); IR and Raman
spectra: K. B. Harvey, N. R. McQuaker, Can.
J. Chem. 49, 3272 (1971). Use as reducing
agent in protein labelling: E. K. J. Pauwels et al., Nucl. Med. Biol. 20, 825 (1993);
in simple reductions: C. Than et al., J. Labelled Compd. Radiopharm. 38, 693 (1996);
J. C. Briggs et al., Tetrahedron 53, 3943 (1997). Review of potassium and other metal
tetrahydroborates: B. D. James, M. G. H. Wallbridge, Prog. Inorg. Chem. 11, 99-231
(1970).
Properties
Non-hygroscopic crystals. Stable to air. d 1.11. nD 1.490. Dec commences at about 500°. Supports combustion. Negative heat
of soln in H2O = 6.3 kcal/mol. Dangerous when wet. Soly (w/w) in water at 25°: 19%;
liquid ammonia at 25°: 20%; ethylenediamine at 75°: 3.9%; methanol
at 20°: 0.7%; DMF at 20°: 15.0%. 0.25 g dissolves in 100 g of 95%
ethanol at 25°. Soly in a 4:1 water-methanol mixture: 13 g/100 g.
Insol (< 0.01%) in isopropylamine, benzene, hexane, ether, dioxane,
tetrahydrofuran and acetonitrile. Alkaline aq solutions are stable.Use
Reducing agent; source of H
-.