Naming Help

[Natalie Swerdlow 3K]

In question 9C.1, the name for [Fe(CN)6]^-4 is hexacyanoferrate(II) ion.
In question 9C.3, the answer says that the formula is K3[Cr(CN)6] for potassium hexacyanidochromate(III).

My question is why is CN in the first question cyano but in question 2, CN is cyanido? Also, why is iron in question one ferrate?

[Julie Mai 1K]

Hello!

I believe cyano and cyanido are interchangeable and either can be used for the ligand CN. I believe cyano is just from an older naming convention. Iron in question one is ferrate because the complex in the coordination compound has an overall negative charge. When a complex in a coordination compound has an overall negative charge, the transition metal has -ate added to it's name. Hope this helped!

[jennaj3k]

Iron is ferrate because for some metals, the Latin name is used for the complex anions. The other metals that use Latin names are Copper (Cuprate), Lead (Plumbate), Silver (Argenate), Gold (Aurate), and Tin (Stannate).

Cyano and cyanido are acutally the same ligand, cyano is just an older naming convention. Lavelle said that cyano and cyanido are both acceptable, the book just uses the "new" naming rules even though the old rules are used in the chemistry field a lot.