Metal complexes with d 8 electron configurations often form square planar comple
ID: 1009247 • Letter: M
Question
Metal complexes with d8 electron configurations often form square planar complexes, forming a total of 4 metal-ligand bonds. How many different compounds can be formed by combination of Ni2+ (a d8 metal), SCN- (thiocyanate, an ambidentate ligand), NH3 (a monodentate ligand), and NH4+ (ammonium, a cation that will not coordinate to a metal, but can be used to balance the ionic charge of an anionic metal complex). Consider all structural, geometric, and linkage isomers when crafting your response. How would the number of complexes change if the complexes adopted tetrahedral, rather than square-planar, geometries?
Explanation / Answer
There are total eight number of complexes possible by Ni2+ metal ion with SCN- and NH3 ligands, those are-----
[Ni(SCN)4](NH4)2
[Ni(NCS)4](NH4)2
cis-[Ni(SCN)2(NH3)2]
trans-[Ni(SCN)2(NH3)2]
cis-[Ni(NCS)2(NH3)2]
trans-[Ni(NCS)2(NH3)2]
[Ni(SCN)3NH3]NH4
[Ni(NCS)3NH3]NH4
If the complexes adopt tetrahedral geometry instead of square planner the the total probable number will be six, there will not be any cis trans isomerism.