Chemistry · Ch 5 — Coordination Chemistry
Linkage Isomers
Linkage Isomers
Linkage isomers arise when an ambidentate ligand -- one with two different possible donor atoms -- is bonded to the central metal through one donor atom in one isomer and through the other donor atom in a second isomer, while every other part of the formula stays identical. The classic textbook pair uses the nitrite ion bonded to Co³⁺: in one isomer the nitrogen atom of NO₂⁻ is the donor (a nitro complex), and in the other the oxygen atom of the same ion is the donor (a nit …
What this figure shows. Two octahedral cobalt complexes drawn side by side, each with five NH₃ ligands (H₃N) occupying five positions around a central Co, and the sixth position occupied by the ambidentate nitrite group. In the left structure the nitrite is drawn bonded to cobalt through its nitrogen atom, with the two oxygens branching off the nitrogen (the nitro form). In the right structure the nitrite is drawn bonded to cobalt through one of its oxygen atoms instead, with the nitrogen and second oxygen branching off (the nitrito/ONO form). Both carry an overall 2+ charge, [Co(NH₃)₅(NO₂)]²⁺, and are formula-identical linkage i …