Advertisements
Advertisements
Question
Why are different colours observed in octahedral and tetrahedral complexes for the same metal and same ligands?
Solution
Lower wavelength is absorbed in octahedral complex than tetrahedral complex for the same metal and ligand. In tetrahedral coordination entity, formation of the d-orbital splitting is inverted and is smaller as compared to the octahedral field splitting. For the same metal-ligand complexes, it can be shown that
`Δ_t = (4/9)Δ_0`.
APPEARS IN
RELATED QUESTIONS
On the basis of crystal field theory, write the electronic configuration for d4 ion if ∆0 < P.
The hexaquo manganese (II) ion contains five unpaired electrons, while the hexacyanoion contains only one unpaired electron. Explain using Crystal Field Theory.
How does the magnitude of Δ0 decide the actual configuration of d orbitals in a coordination entity?
State the superiority of crystal field theory over valence bond theory.
Atomic number of \[\ce{Mn}\], \[\ce{Fe}\] and \[\ce{Co}\] are 25, 26 and 27 respectively. Which of the following inner orbital octahedral complex ions are diamagnetic?
(i) \[\ce{[Co(NH3)6]^{3+}}\]
(ii) \[\ce{[Mn(CN)6]^{3-}}\]
(iii) \[\ce{[Fe(CN)6]^{4-}}\]
(iv) \[\ce{[Fe(CN)6]^{3-}}\]
Match the complex ions given in Column I with the hybridisation and number of unpaired electrons given in Column II and assign the correct code:
| Column I (Complex ion) | Column II (Hybridisation, number of unpaired electrons) |
| A. \[\ce{[Cr(H2O)6]^{3+}}\] | 1. dsp2, 1 |
| B. \[\ce{[Co(CN)4]^{2-}}\] | 2. sp3d2, 5 |
| C. \[\ce{[Ni(NH3)6]^{2+}}\] | 3. d2sp3, 3 |
| D. \[\ce{[MnF6]^{4-}}\] | 4. sp3, 4 |
| 5. sp3d2, 2 |
Using crystal field theory, draw energy level diagram, write electronic configuration of the central metal atom/ion and determine the magnetic moment value in the following:
\[\ce{[FeF6]^{3-}, [Fe(H2O)6]^{2+}, [Fe(CN)6]^{4-}}\]
Using crystal field theory, write the electronic configuration of d5 ion, if Δ0 > P.
For octahedral Mn(II) and tetrahedral Ni(II) complexes, consider the following statements:
(i) Both the complexes can be high spin.
(ii) Ni(II) complex can very rarely below spin.
(iii) With strong field Ligands, Mn(II) complexes can be low spin.
(iv) Aqueous solution of Mn (II) ions is yellow in colour.
The correct statements are:
On the basis of crystal field theory, write the electronic configuration for d4 with a strong field ligand for which Δ0 > P.
