Test: Structural and stereoisomerism in Coordination Complexes - Chemistry MCQ

The optical isomers are of two types based on the direction they rotate the plane of polarised light in a polarimeter. If it rotates it to the right, it is called dextro and if it rotates it to the left, it is called laevo.

Fac-mer isomerism is only exhibited in octahedral coordination entities of the type [MA3B3] depending on the positions of the similar ligands.

In square planar complexes, the type [MXL3] does not have any isomers as there is no pair of ligands that can be arranged adjacent to or opposite each other to form cis or trans forms respectively. All possible combinations result in the same spatial arrangement.

In a complex of such type, the two A ligands can be arranged either adjacent to or opposite each other to form cis and trans isomers respectively, making it a total of two possible isomers.

Tetrahedral complexes do not form geometric isomers as the relative positions of all the ligands will always be same because of the geometric properties of a tetrahedron.

In a square planar complex of formula [MX2L2 ] (X and L are unidentate), the two ligands X may be arranged adjacent to each other in a cis isomer, or opposite to each other in a trans isomer

Geometrical isomerism is a type of stereoisomerism. Linkage, coordination and ionisation isomers show structural isomerism with different bonds.

Isotopes are forms of one element due to different number of neutrons in each atom. Isotones are forms of different elements that have the same number of neutrons and allotropes are the different physical forms in which a given element can exist.

Optical isomers are different forms of the same complex that are mirror images of each other, and which cannot be superimposed. They are chiral complexes also known as enantiomers.

Octahedral entities of the type [MA3B3] form two types of isomers based on whether the same ligand groups occupy adjacent positions on the octahedral face (fac) or positions around the meridian of the octahedron (mer).

If you observe the two given cis isomers, it can be seen that they are formed by simply swapping the positions of B and C, but both of them are adjacent to each other in both isomers. So, to obtain the trans isomer, the ligands B and C should lie opposite to each other. The other incorrect options are the same cis isomers but are depicted in different orientations.

The compound [Pt(NH₃)₂Cl₂] forms two geometric isomers, one cis and one trans. When the two Cl ligands are arranged adjacent to each other, a cis isomer is formed and when the two Cl ligands are opposite to each other, a trans ligand is formed.

The entity shown has a CN=6 as oxalate is a bidentate ligand. The structure of the entity will be same no matter which positions in the geometry each of the oxalate ligands occupy because their relative positions will remain the same in each case.

Geometrical isomerism takes place only in heteroleptic ligands as there is more than one type of bonding group that can be arranged in different possible manners to give rise to isomers.

Stereoisomers have the same chemical formula and binds but have different spatial arrangement. Optical isomerism is a type of stereoisomerism.