Hello, reders welcome to “chemwhite.com” today i am going to explain about the term spectrochemical series.

What is spectrochemical series?

Actually, the main function of spectrochemical series, they developed the arrangement of ligands in the increases order of crystal field splitting. It is arrangements of ligands from weak ligands and strong ligands. this is known as spectrochemical series.

but crystals field splitting is greater if ligands are stronger and they form complex with the help of high spin.

Adsorption of light by coordination compound with different ligands are know as spectrochemical series.

Read MoreWhat are inner-transition elements?

Difference between weak field ligands and strong field ligands

  1. Weak filed ligands
  2. Stronge field ligands

Weak field ligands – It mean, less splitting of crystal field. and thy form complex with the help of high spin.

The arrangements of ligands on the basis of electrons pair (loan pair) doner ability. this mean, ligands have ability to break down of reservancy for central metals ion of d orbitals. this type of legands is known as stronge ligands.

for examples,

Doner atom is oxygen and sulfur and helogen.

(a) H2O

(b) OH-

(c) Cl-

(d) Br-, SCN-, O-2, NO3- and more

Chlorine ions and fluoride ion

stronge field ligands – It mean, greater splitting of crystal field. and they form complex with the help of low spin.

or

The arrangements of ligands on the basis of electrons pair (loan pair) doner ability. this mean, ligands have not ability to break down of reservancy for central metals ion of d orbitals. this type of legands is known as weak ligands.

for examples,

Carbon doner ligands and nitrogen doner ligands are the best example of strong ligands.

(a) NH3

(b) NO2-

(c) CN-

(d) eN

(e) dipy

(f) CO and cyanide ion.

Importance of spectrochemical series?

  1. The arrangements of ligands on the basis of electrons pair (loan pair) doner ability.
  2. loan pair doner either carbon or nitrogen.
  3. strong ligands means, having ability of loan pair doner atom. for examples, carbon and nitrogen.
  4. ligands have ability to break down of reservancy of central metals ion of d orbitals. this type of legands is known as stronge ligands.
  5. weak ligands means, doner atom should be oxygen, and sulfur.
  6. weak ligands having ability doner atom such as oxygen, sulfur and helogen.
  7. ligands have not ability to break down of reservancy for central metals ion of d orbitals. this type of legands is known as weak ligands.
  8. In case of weak ligands, doner atom such as, oxygen (O) sulphur (S) and helogen (F, Cl, Br, l).
  9. The best examples of weak ligands are,
  10. Weak ligands are, H2O, OH-, Cl- , Br- , NO3- , O-, SCN-, NO3-
  11. The best example of strong ligands are,
  12. Strong ligands are, CN-, NO2-, dipy, eN, NH3.

Electrochemical series / Reactivity series

  1. K (potassium) Pb (Lead)
  2. Na (sodium) H (hydrogen)
  3. Ca (calsium) Cu (copper)
  4. Mg (magnesium) Ag (silver)
  5. Al (Aluminium) Au (gold)
  6. Zn (Zinc) pt (platinum)
  7. Fe (iron)
  8. Sn (Tin)

Short tric of spectrochemical series

It is define as the series obtained when ligands are arange according to CFSE (crystal field stable energy). the series obtained is called spectrochemical series.

The starting ligands of spectrochemical series are I, Br (halogen) these are weak ligands.

In between of spectrochemical series are H2O.

Strongest ligands are CN-, CO.

Arrangements of weak field ligands

I- < Br- < Cl- < SCN- < F- < OH- < CH3COO- < C2O4 < H2O.

Arrangment of strong field ligands

HCN < NH3 < Py < en < diph < NO2 < H- < CO-

Arrangment of ligands in order their field strength.

electrochemical series


0 Comments

Leave a Reply

Avatar placeholder

Your email address will not be published.