Advertisements
Advertisements
Question
How does the magnitude of Δo decide the actual configuration of d orbitals in a coordination entity?
Advertisements
Solution
- If Δ0 < P, the fourth electron enters one of the eg orbitals giving the configuration \[\ce{t^3_{2g}e^1_g}\]. Ligands for which Δ0 < P are known as weak field ligands and form high spin complexes.
- If Δ0 > P, it becomes more energetically favourable for the fourth electron to occupy a t2g orbital with configuration \[\ce{t^4_{2g}e^0_g}\]. Ligands which produce this effect are known as strong field ligands and form low spin complexes.
APPEARS IN
RELATED QUESTIONS
Complete and balance the following reactions:
\[\ce{P4 + H2SO4 ->}\] ______ + ______ + ______
The colour of the coordination compounds depends on the crystal field splitting. What will be the correct order of absorption of wavelength of light in the visible region, for the complexes, \[\ce{[Co(NH3)6]^{3+}}\], \[\ce{[Co(CN)6]^{3-}}\], \[\ce{[Co(H2O)6]^{3+}}\]
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) \[\ce{[Fe(CN)6]^{3-}}\]
An aqueous pink solution of cobalt (II) chloride changes to deep blue on addition of excess of HCl. This is because:
(i) \[\ce{[Co(H2O)6]^{2+}}\] is transformed into \[\ce{[CoCl6]}^{4-}\]
(ii) \[\ce{[Co(H2O)6]^{2+}}\] is transformed into \[\ce{[CoCl4]}^{2-}\]
(iii) tetrahedral complexes have smaller crystal field splitting than octahedral complexes.
(iv) tetrahedral complexes have larger crystal field splitting than octahedral complex.
On the basis of crystal field theory explain why Co(III) forms paramagnetic octahedral complex with weak field ligands whereas it forms diamagnetic octahedral complex with strong field ligands.
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:
\[\ce{[CoF6]^{3-}, [Co(H2O)6]^{2+}, [Co(Cn)6]^{3-}}\]
The CFSE for octahedral [CoCl6]−4 is 18,000 cm−1. What will be the CFSE for tetrahedral [CoCl3]−2?
Considering crystal field theory, strong-field ligands such as CN–:
Crystal field stabilising energy for high spind4 octahedral complex is:-
The CFSE of [CoCl6]3– is 18000 cm–1 the CFSE for [CoCl4]– will be ______.
What is crystal field splitting energy?
The correct order of intensity of colors of the compounds is ______.
Consider that d6 metal ion (M2+) forms a complex with aqua ligands and the spin only magnetic moment of the complex is 4.90 BM. The geometry and the crystal field stabilization energy of the complex are ______.
On the basis of Crystal Field theory, write the electronic configuration for the d5 ion with a strong field ligand for which Δ0 > P.
On the basis of crystal field theory, write the electronic configuration for d4 with a strong field ligand for which Δ0 > P.
Read the passage carefully and answer the questions that follow.
|
Crystal field splitting by various ligands Metal complexes show different colours due to d-d transitions. The complex absorbs light of specific wavelength to promote the electron from t2g to eg level. The colour of the complex is due to the transmitted light, which is complementary of the colour absorbed. The wave number of light absorbed by different complexes of Cr ion are given below:
|
Answer the following questions:
(a) Out of ligands "A", "B", "C" and "D", which ligand causes maximum crystal field splitting? Why?
OR
Which of the two, “A” or “D” will be a weak field ligand? Why?
(b) Which of the complexes will be violet in colour? [CrA6]3- or [CrB6]3+ and why?
(Given: If 560 - 570 nm of light is absorbed, the colour of the complex observed is violet.)
(c) If the ligands attached to Cr3+ ion in the complexes given in the table above are water, cyanide ion, chloride ion, and ammonia (not in this order).
Identify the ligand, write the formula and IUPAC name of the following:
- [CrA6]3-
- [CrC6]3+
The correct order of the wavelength of light absorbed by the following complexes is:
- [Co(NH3)6]3+
- [Co(CN)6]3−
- [Cu(H2O)4]2+
- [Ti(H2O)6]3+
Choose the correct answer from the options given below:
