[zarabat]

diethyle ether is non polar solvent and I am using it for solving magnesium borohydride(Mg(BH4)2)

according to my observation while its evaporation temperature is about 35 C but when I want to remove it again, it forms very stable compound which is even stable till 300 C!! (DTA /MS device shows that it removes between 200 to 300 C!!)
after grinding this stability range will reduce to 40 -160 C!!

could you please tell me what is going on here? after first removal? after grinding? after second removal(removal of ether after grinding)?

thanks

[discodermolide]

I don't know what's going on but it is probably forming a solvated species.
If I were you I would be very careful grinding this material, it may just exothermically decompose. See http://link.springer.com/article/10.1007%2FBF00849335?LI=true#page-1

[zarabat]

Thanks for your answer

actually I know my compound form a Lewis complex with ether but I wonder that how is it possible to that much stable? are all Lewis complexes are that much stable? and the next one is why after grinding stability is decreased?

Decomposition temperature for this compound is more that 200 C (start to release H2 after 200 C), do you think grinding can produce that much temperature?

thanks 

[discodermolide]

The stability of such complexes varies tremendously. I have no idea why this one is so stable.
Grinding a compound can locally produce very high temperatures initiating exothermic decomposition.

[zarabat]

Can you suggest any references which I can take a look at them? and get more idea on mechanism of these kinds of complexes?