Geometrical Isomers in Coordination Compounds

Cisplatin saves lives. Transplatin, with exactly the same atoms, does not. What is the difference? Only where the ligands sit in space.

When geometrical isomerism happens (square planar and octahedral, never tetrahedral), how to draw every isomer, and how to count them quickly for MA2B2, MABCD, MA4B2, MA3B3 (fac and mer), MA2B2C2 and more. Also chelating ligands such as en, why optical isomerism is a separate question, and four exam-style practice questions.

Study: Coordination Compounds →   Watch on YouTube

In this video

• 0:00The hook: cisplatin vs transplatin
• 0:50What is geometrical isomerism, and where it occurs
• 2:02Square planar: MA2B2, MA2BC, MABCD
• 3:30Square planar: when there are none (the trap)
• 5:04Octahedral: MA4B2, MA4BC, MA5B
• 6:24MA3B3: fac and mer
• 7:47Chelating ligands and optical isomers
• 9:17Counting hard patterns: MA2B2C2, MA3B2C
• 10:56Why isomers differ: cisplatin and DNA
• 12:17Practice: four exam-style questions
• 13:34Recap and close