Answer: CN-, CO, NO+ > H- > CH 3 - > PR 3 > SC(NH 2 ) 2 > NH 3 > NR 3 > Cl- > Br- > I- > H 2 O.
- A CN-, CO, NO+ > H- > CH<sub>3</sub><sup>-</sup> > PR<sub>3</sub> > SC(NH<sub>2</sub>)<sub>2</sub> > NH<sub>3</sub> > NR<sub>3</sub> > Cl- > Br- > I- > H<sub>2</sub>O
- B H<sub>2</sub>O > Cl- > CN-, listed in the reverse order of true trans-labilising strength
- C All ligands shown to labilise the trans position with identical strength
- D Only the halogen ligands shown to exhibit any trans effect at all
Correct answer: A. CN-, CO, NO+ > H- > CH<sub>3</sub><sup>-</sup> > PR<sub>3</sub> > SC(NH<sub>2</sub>)<sub>2</sub> > NH<sub>3</sub> > NR<sub>3</sub> > Cl- > Br- > I- > H<sub>2</sub>O
Explanation: Strong pi-acceptors (CO, CN-, NO+) and strong sigma-donors (H-, alkyl) have the greatest trans-labilising effect in Pt(II) kinetics.
The three common coordination geometries: octahedral (6 ligands), tetrahedral (4 ligands), and square planar (4 ligands in one plane).
Concept context
Study of compounds where a central metal atom is bonded to surrounding ligands. Covers nomenclature, types of isomerism, bonding theories (VBT, CFT), and applications in medicine, photography, and industry.