3. ISOMERS IN COMPLEX IONS

stereoisomerism

same molecular formula different arrangement of atoms in space

optical isomerism

type of stereoisomerism

complex ion optical isomers exist as 2 non-superimposable mirror images

this happens in octahedral complexes when 3 bidentate ligands are attached to the central ions

Cis-trans isomerism occurs in square planar complex ions

square planar complex ions have 2 pairs of ligands

TRANS = when 2 paired ligands are diagonal each other

CIS = when 2 paired ligands are next to each other

cisplatin

a complex of platinum2 with 2 chloride ions and 2 ammonia molecules in a square planar shape

cancer is caused by

uncontrolled cell division leading to the formation of tumours

cisplatin can be used to treat some types of cancer

cisplatin is active against a variety of cancers including lung and bladder cancer because it prevents cancer cells from reproducing

octahedral complexes w 4 ligands of 1 type and 2 ligands of another type

can also exhibit cis trans isomerism

if the 2 odd ligands are opposite each other

TRANS ISOMER

if the 2 odd ligands are next to each other

CIS ISOMER