A cobalt(III) centre form a complex with five ammine ligands, and ONE sulfate counter ion. What is its likely formulation?

1 Answer
Feb 11, 2016

Given the formula, the sulfate probably occupies the #1# coordination site on the octahedral cobalt centre.


Given this formulation, the parent complex ion is likely, #[Co(NH_3)_5(OSO_3)]^+#, in which the sulfato ligand acts as a unidentate donor towards the octahedral #Co(III)# centre. I don't know the lingo with respect to secondary and primary valences.