Question

Identify the correct naming for [Co(ONO)(NH3)5]^2+.

(a) Pentaamminenitritocolbalt(III)

(b) Pentaamminenitrito-O-cobalt(III)

(c) Pentaamminenitrito-N-cobalt(III)

(d) Pentaamminenitrosylcobalt(III)

This question was posed to me by my college director while I was bunking the class.

My query is from Nomenclature of Coordination Compounds topic in division Coordination Compounds of Chemistry – Class 12

Answer 1

Correct answer is (b) Pentaamminenitrito-O-cobalt(III)

The explanation is: Nitrate is an ambidentate ligand and can bind through either O or N atom. In this case, it is written as (ONO) which implies that it binds through O atom, hence giving it the name nitrito-O.