David Marx - 29-8-2004 at 16:06
Does anyone have a good tried method for brominated lanthanides? Currently, I am trying to brominate lanthanum oxide, though I forsee a future need
to brominate other trivalent lanthanide elements.
Any comments would be appreciated.
BromicAcid - 29-8-2004 at 17:28
It depends on what you want. Looking up the properties of the chloride it states that it forms the heptahydrate and upon heating to 91C it
decomposes, to what it does not say, but if it simply lost the water of hydration it would say so. Therefore an oxychloride (O=La-Cl) may be formed
or something of that nature. Therefore my idea to heat La2O3 with HBr (aq) to form the bromide then crystallize it out would not work to well if you
wanted anhydrous LaBr3, but it should work for making the hydrate.
Running HBr(g) over heated La2O3 should produce some anhydrous LaBr3 but the way that I would have to go for a decent yield of high purity product
would be to run a heated stream of hydrogen over the lanthanum oxide to reduce it followed by reaction with Br2 vapor.
neutrino - 1-9-2004 at 12:19
According to Lange's 15th, LaCl<sub>3</sub> goes adhydrous at 852*C (also the melting point of the anhydrate) in an HCl atmosphere,
with no mention of decomposition. I wonder if this can be applied to the bromide.