Hi,
I am trying to crystallize H5PV2Mo10O40 POM in presence of 10 M H2SO4. I know that the POM is not stable at such high acid concentration but I want to get the crystal of the decomposed/polymerized species in solution to solve it by Single crystal XRD. Any valuable suggestion will be highly appreciated.
Thanks in advance
I am not exactly following what you would like to do here. You know the POM is not stable but you want to get a crystal of the decomposed material? Could you explain a little more?
generally speaking , the polyoxometalates are unstable in the basic solutions, at pH=4 the polyoxometalates decompose giving rise to fragments,
I understand that you want to crystallize these fragments, I think you have to dissolve your compound until saturation in acitonitrile then you adjust the pH to a value higher than 4 and you have to heat your solution until all of your compound is dissolved, and then you bring your solution to room temperature, you will notice the appearance of the crystals after 5-7 days.
good luck
The best way to crystallize polyoxometallates is to use hydrothermal conditions because many components could be dissolved in water solution at temperature range 150-200C(at the corresponding high pressure). Then depending on the pH in different vessels after slow temperature decreasing you probably will be lucki to isolate many of products (including decomposed\polimerized). so, I believe you will get some materials not only for powder but for single xtal XRD.
Thank you very much Eduard Rusanov , This method seems reasonable and I am gonna try it.
Ok, just remember that typical pressure at the wessels in such temp. range aprox. 10-20 bar, so you should use specific ones ang please use any possible shilding to protect yourself and other in your lab!
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