Friday, July 19, 2019

inorganic chemistry - Which metals hydroxides dissolve in excess NH4OH?


Some metal hydroxides like $\ce{Ag(OH)}$ and $\ce{Cu(OH)2}$ dissolve in excess $\ce{NH4OH}$ to form metal ammonia complexes.


I want to know which other common metal hydroxides dissolve in excess $\ce{NH4OH}$. Also, can it be somehow predicted ? I couldn't find much relevant information on the Internet.



Answer



The Wikipedia article for "Metal amine complex" gives many examples. According to the article:



Almost all metal ions bind ammonia as a ligand, but the most prevalent examples of ammine complexes are for Cr(III), Co(III), Ni(II), Cu(II) as well as several platinum group metals.



Specific examples include:


$\ce{[Pt(NH3)4][PtCl4]}$

$\ce{[RhCl(NH3)5]Cl2}$
$\ce{[Cr(NH3)4Cl2]Cl}$
$\ce{[Co(NH3)6]Cl3}$
$\ce{NH4[Cr(NCS)4(NH3)2]}$
$\ce{[Zn(NH3)4]^2+}$
$\ce{[Ag(NH3)2]+}$
$\ce{[Ni(NH3)6]^2+}$
$\ce{[Cu(NH3)4(H2O)2]^2+}$


Several others are listed just in that one Wikipedia article, along with a fair list of references.


No comments:

Post a Comment

digital communications - Understanding the Matched Filter

I have a question about matched filtering. Does the matched filter maximise the SNR at the moment of decision only? As far as I understand, ...