Chemical Forums
Chemistry Forums for Students => Inorganic Chemistry Forum => Topic started by: transient on November 09, 2007, 10:38:05 AM
-
Having problems with the structure and preparations of bisthioureacopper(II) sulfate & tristhioureacopper(I) sulfate
I expect tris(tu)copper(I) to be octahedral but is the copper(II) complex tetrahedral or square planar?
also to prepare tris(tu)copper(I)sulfate from copper(II)sulfate what would the correct reaction pathway be?
CuSO4 + 2tu --> [Cu(tu)2]SO4
[Cu(tu)2]SO4 + H2SO4 + tu --> [Cu(tu)3]SO4 ... ???
is the sulfuric acid acting as a reducing agent here? or is there something i'm missing?
please help can't find much about these compounds!!
-
think i figured it out... hope i am right:
To produce a sample of tristhioureacopper(I)sulfate from a starting material of copper(II)sulphate we must do two things:
a) Reduce the copper(II) to copper (I)
b) Introduce the thriourea ligand
Conveniently the thiourea itself can act as a reducing agent via it’s own oxidation;
2CS(NH)2(aq) --> [(H2N)2CSSC(NH)2]2+(aq) + 2H+(aq) + 4e-(aq)
Oxidation product exists as a dimer
The reduction reaction for the copper(II) is simply;
Cu2+(aq) + e-(aq) --> Cu+(aq)
The full redox equation being;
4CuSO4(s) + 2CS(NH2)2(s) --> 2Cu2SO4(s) + [(H2N)2CSSC(NH)2]SO4(l) + SO42-(aq)
Observed as oily droplets
Reaction is carried forward by the reaction of Cu2SO4 with additional thiourea and the dimer produced above to form the final complex.
6CS(NH2)2(aq) + Cu2SO4(aq) --> [Cu(CS(NH2)2)3]2SO4(s)
The final product exists as a dehydrate with an octahedral structure.
can anyone verify this please?
-
i mixed 2.5g of CuSO4.5H2O wid aqueous solution of 2.5 g thiourea.....precipitates of tristhioureacopper(1) sulfate were supposed to beformed...but it turned out to be a camel coloured gum like product.
do i had to add sulfuric acid to get the product ?????in the procedure we r not asked to add the acid though....can some one help me wid this ???
-
it's been a while since i carried out this experiment now but we had used a mixture of sulfurous acid & glacial acetic acid; i believe the purpose was to reduce our copper(II) starting product to a Copper(I) salt before adding the thiourea
but like i said it's been a while.