Bedlasky - 4-5-2021 at 18:51
Hi.
I play around little bit with copper complexes with tris. I made two of them - [Cu(H-1tris)2(H2O)]
(H-1tris means deprotonated tris) and [Cu(tris)4)(ClO4)2.
The first one contain copper with coordination number five, which is quite unusual for copper. It have nice dark blue colour (very different from
tetraamminecopper(II)) and preparation is very easy.
The second one is energetic complex. Not truly explosive (at least in small amount). Experimenting with this compound was really fun. I am honestly
surprised that it burn so well, because most of the oxygen was consumed on water formation and only 4 oxygens left for 16 carbons. Preparation is
little bit trickier than for the first complex - you need to evaporate solution in CaCl2 dessicator, solution refuse to fully dehydrate by just simple
evaporation.
More info, photos and videos in my article CZ/EN.
vano - 4-5-2021 at 20:59
Interesting complex, it has very nice colour. You was right, the solution is really different in color from the ammonia complex.
Lion850 - 4-5-2021 at 21:58
I like the videos 
woelen - 5-5-2021 at 10:56
Very interesting experiments. Especially the so-called H-1tris-complex is interesting. If I look at the structure, the TRIS loses a hydrogen ion at
one of the hydroxy-groups. I expected TRIS to be a somewhat alkaline compound, due to the presence of the amine-group, but here it acts as an acid,
albeit in a very special way.
I have CuO and TRIS. I can try this experiment with CuO, although I expect the CuO to dissolve with much more difficulty (even with HClO4, the
reaction is quite slow and excess CuO is needed to get all HClO4 reacted in reasonable time).
[Edited on 5-5-21 by woelen]
DraconicAcid - 5-5-2021 at 11:09
It doesn't surprise me that the hydroxyl can be deprotonated when chelating a copper(II) ion- apparently, lactate ion and ethylene glycol will do the
same.
woelen - 5-5-2021 at 11:14
What surprises me is not only the deprotonation of an hydroxy-group, but in this particular structure. Hydroxy groups being deprotonated are very
common (nearly all oxoacids, including organic acids with a -C(O)OH group have them). Deprotonation of a hydroxy-group, on a C-atom with just
hydrogens and another C-atom on it, are much less common though. Apparently, the NH2-group makes the deprotonation easier, even through two C-atoms.
Bedlasky - 5-5-2021 at 16:30
Draconic acid: I always thought that this complex is formed with neutral ethylene glycol. I searched it online and this complexes is really
interesting - sodium ions coordinated to ethylene glycol as cation and copper coordinated to deprotonated ethylene glycol as anion.
DraconicAcid - 5-5-2021 at 17:18
I honestly don't remember the exact details, but depending on pH, you can have singly- or doubly- deprotonated ethylene glycols coordinated to copper.