Answer:
Step-by-step explanation:
To determine which of the given complexes can exist as enantiomers, we need to consider the presence of chiral centers or elements of symmetry in each complex. Enantiomers are mirror images of each other and cannot be superimposed onto each other.
(a) cis-[CO(NH₃)4Br₂]⁺⁻:
This complex does not have any chiral centers or elements of symmetry. Therefore, it cannot exist as enantiomers.
(b) cis-[Cr(H₂O)₂(en)₂]³⁺:
This complex contains the ligand "en" (ethylenediamine), which has two chiral centers. Therefore, it can exist as enantiomers.
(c) [Cr(gly)₃]:
This complex does not have any chiral centers or elements of symmetry. Therefore, it cannot exist as enantiomers.
(d) [Cr(en)₃]³⁺:
This complex also contains the ligand "en" (ethylenediamine), which has two chiral centers. Therefore, it can exist as enantiomers.
(e) cis-[CO(NH₃)Cl(en)₂]²⁺:
This complex contains the ligand "en" (ethylenediamine), which has two chiral centers. However, the presence of the cis configuration indicates that the ligands are not arranged in a way that allows for enantiomerism. Therefore, it cannot exist as enantiomers.
(f) trans-[CO(NH₃)₂(en)₂]²⁺:
This complex contains the ligand "en" (ethylenediamine), which has two chiral centers. The presence of the trans configuration allows the ligands to be arranged in a way that allows for enantiomerism. Therefore, it can exist as enantiomers.
In summary, the complexes that can exist as enantiomers are:
(b) cis-[Cr(H₂O)₂(en)₂]³⁺
(d) [Cr(en)₃]³⁺
(f) trans-[CO(NH₃)₂(en)₂]²⁺
Please note that ligands with chiral centers, like "en" in this case, can give rise to enantiomers when arranged in different spatial orientations.