Question

The 1,10-phenanthroline complex below was discovered in the 1950's and 1960's to have a range of biological activities, which rekindled an interest in using metal complexes as drugs. a) Label the optical isomer drawn, draw and label the other optical isomer (without the detailed ligand structure) and give the systematic name of the second isomer. (3 marks) Isomer Label: Structure of other isomer 2+ N Complex Name: b) Briefly explain why these two isomers have different biological activities (1 mark)

Answer 1

The structure of the other isomer is just the mirror image of the given isomer as they are chiral enantiomers. The label given to the given isomer is Capital Lambda-(+) and the label to the drawn isomer is Capital Delta-(-). The name of the complexes is (+)- or (-)-tris-ethylenediamine iron(II). The detailed solution is given below:

Answer : (a) Structue of other is omer: Labels: A-(+) and A-(-) IN? Given - A-(-)-[Fecenzjet Complex Name : A-(+)-[fe Cent, 3+ (+)- or ()- tris-ethylenedianure ison (II) complexed. wz y (b). The complex [Fe (enly] et is configurationally labile and it it could be obtained as optically pure in one enantiomeric form then it would racemize rapidly. That is why they are biologically different as they form (t) 1 and (-) salts racemic mixture.