Answer: Cisplatin [cis-Pt(NH 3 ) 2 Cl 2 ] by exploiting that Cl- has stronger trans-labilising effect than NH 3.
- A Cisplatin [cis-Pt(NH<sub>3</sub>)<sub>2</sub>Cl<sub>2</sub>] by exploiting that Cl- has stronger trans-labilising effect than NH<sub>3</sub>
- B A largely random, loosely controlled mixture of cis and trans geometric isomers in many documented cases
- C Mainly the trans isomer of the platinum complex with little cis product formed according to conventional understanding
- D Octahedral platinum complexes formed instead of the intended square planar product in routine practice
Correct answer: A. Cisplatin [cis-Pt(NH<sub>3</sub>)<sub>2</sub>Cl<sub>2</sub>] by exploiting that Cl- has stronger trans-labilising effect than NH<sub>3</sub>
Explanation: Trans effect: by starting with [PtCl<sub>4</sub>]2- and adding NH<sub>3</sub>, Cl- labilises the trans position; the second NH<sub>3</sub> goes cis because of the kinetic trans effect, giving cisplatin.
Aqueous solutions of transition metal ions show characteristic colours caused by electrons absorbing visible light to jump between split d-orbitals; the exact colour depends on the metal, its oxidation state, and surrounding ligands.
Concept context
Transition metals (d-block) and lanthanides/actinides (f-block). Known for coloured compounds, variable oxidation states, complex formation, and catalytic properties. Frequently tested in JEE and NEET.