Option (1)
[MnBr4]2− Br− weak ligand does not allow pairing of
e−s,therefore, hybridization of the Mn in complex is sp3 and geometry is tetrahedral.
Option (2)
[Ni(NH3)6]2+ NH3 is a strong field ligand, therefore, pairing of electrons will take place. But due to insufficiency of vacant orbital, pairing will not take place
Electronic configuration of Ni (Z = 8)
[Ar]3d84s2 Electronic configuration of
Ni2+ is
[Ar]3d8 Ni2+ in the presence of strong field ligand
It is outer orbital complex and not an inner orbital complex
Option (3)
[Co(NH3)6]2+ NH3 is a strong field ligand, therefore, pairing will take place
Electronic configuration of Co (Z = 27) is
[Ar]3d74s2 Electronic configuration of
Co2+ is
[Ar]3d7 Co2+ in the presence of strong field ligand.
There is one unpaired
e− therefore, it is paramagnetic
Option (4)
[CoBr2(en)2]− does not have ambidentate ligands, therefore, is does not exhibits linkage isomerism.