Question

Write IUPAC names of the following coordination compounds: (i) [CrCl\(_2\)(en)\(_2\)]Cl
(ii) Cs[FeCl\(_4\)]
(iii) K\(_3\)[Co(C\(_2\)O\(_4\))\(_3\)]
(iv) [CoCl\(_3\)(NH\(_3\))\(_3\)]

Hint:

Always name ligands alphabetically, specify coordination number, and oxidation state in Roman numerals.

Answer 1

(i) [CrCl\(_2\)(en)\(_2\)]Cl: Coordination sphere contains 2 Cl\(^-\) ligands and 2 en ligands. Oxidation state of Cr = +3. Name = Dichloridobis(ethane-1,2-diamine)chromium(III) chloride.
(ii) Cs[FeCl\(_4\)]: Complex anion = [FeCl\(_4\)]\(^-\). Oxidation state of Fe = +3. Name = Caesium tetrachloridoferrate(III).
(iii) K\(_3\)[Co(C\(_2\)O\(_4\))\(_3\)]: Oxidation state of Co = +3. Oxalate = bidentate ligand. Name = Potassium tris(oxalato)cobaltate(III).
(iv) [CoCl\(_3\)(NH\(_3\))\(_3\)]: Coordination sphere has 3 Cl\(^-\), 3 NH\(_3\). Oxidation state of Co = +3. Name = Triamminetrichloridocobalt(III).