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Author: Subject: Synthesis of an artificial analogue of a molybdenum mineral
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[*] posted on 14-6-2007 at 19:41
Synthesis of an artificial analogue of a molybdenum mineral

I am trying to synthesize artificial Szenicsite and Lindgrenite in a laboratory, but I do not know how to do this. Szenicsite is Cu3(MoO4)2(OH)4 and Lindgrenite is Cu3(MoO4)2(OH)2

I managed to synthesize CuMoO4 as a starting point by reacting 2g of anhydrous CuCl2 with 3.1g anhydrous Na2MoO4, both placed in boiling water. I obtained about 2.7g CuMoO4 (theoretical yield is 3.32g). It reacted as follows-

CuCl2 + Na2MoO4 -----Heat----> CuMoO4 (s) + 2 NaCl (aq)

I then filtered and dried in a crucible to yield a dry powder of "pea soup" green CuMoO4

Today, I made another batch of the stuff (same masses of reactants), but after preparing the molybdate, I reacted it with 1.19g NaOH, 2g more CuCl2 (anhydrous), and 3.1g more Na2MoO4 intending to synthesize Lindgrenite. I added the NaOH to the boiling solution of precipitated Cu Molybdate and water. It then turned black, yielding CuO. Then I added the CuCl2 and Na2MoO4 andstirred. The solution then turned "pea soup" green again but there was obviously a lot more molybdate precipitating out. I originally intended to synthesize Lindgrenite, but I think I just got a lot more Cu Molybdate.

Here's the reaction that I thought would produce my Lindgrenite .but alas, chemicals are fickle creatures and it didn't work (or so I think)-

CuMoO4 +2NaOH + 2 CuCl2 + NaMoO4 -----heat----> Cu3(MoO4)2(OH)2 (s) + 4 NaCl (aq)


Here's what happened in reality-

CuMoO4 + 4 NaCl (in solution from synthesis of CuMoO4)+ 2NaOH---heat---> CuO +MoO3 + Na2O (aq) + H2O

which I then added CuCl2 and NaMoO4 to-

CuO +MoO3 + Na2O (aq) + H2O + 2 CuCl2 + NaMoO4 -------> 2 CuMoO4 + CuCl2 (aq) + 6NaCl


How could I go about synthesizing Lindgrenite and Szenicsite succesfully?

Thanks!
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[*] posted on 14-6-2007 at 21:14


I suspected that this would have to be done by hydrothermal methods, and a search suggests this is true

Hydrothermal synthesis of lindgrenite

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi...

attached
Influence of 2-aminopyridine on the formation of molybdates under hydrothermal conditions

[Edited on 15-6-2007 by not_important]

Attachment: EJIC2005a.pdf (293kB)
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