English

Why Are Low Spin Tetrahedral Complexes Rarely Observed? - Chemistry

Advertisements
Advertisements

Question

Why are low spin tetrahedral complexes rarely observed?

Advertisements

Solution

The orbital splitting energies are not sufficiently large for forcing pairing and, therefore, low spin configurations are rarely observed.

shaalaa.com
  Is there an error in this question or solution?
2016-2017 (March) All India Set 3

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

State the superiority of crystal field theory over valence bond theory.


 Write the electronic configuration of Fe(III) on the basis of crystal field theory when it forms an octahedral complex in the presence of (i) strong field, and (ii) weak field ligand. (Atomic no.of Fe=26) 


Arrange following complex ions in increasing order of crystal field splitting energy (∆O):

\[\ce{[Cr(Cl)6]^{3-}, [Cr(CN)6]^{3-}, [Cr(NH3)6]^{3+}}\].


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:

\[\ce{[FeF6]^{3-}, [Fe(H2O)6]^{2+}, [Fe(CN)6]^{4-}}\]


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:


The correct order of intensity of colors of the compounds is ______.


The complex that has highest crystal field splitting energy (Δ) is ______.


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:

Complex Wavenumber of light absorbed (cm-1) Energy of light absorbed (kJ/mol)
[CrA6]3- 13,640 163
[CrB6]3+ 17,830 213
[CrC6]3+ 21,680 259
[CrD6]3- 26,280 314

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:

  1. [CrA6]3-
  2. [CrC6]3+

On the basis of Crystal Field Theory, write the electronic configuration of d4 ion if Δ0 > P.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×