It is the ppt that describes the properties of d block elements,and comparision of 3d,4d,5d elements of d block elements

1. KUVEMPU UNIVERSITY
Department of P.G. Studies and Research in Chemistry
Jnana Sahyadri, Shankaraghatta – 577 451
A SEMINAR ON
COMPARATIVE STUDY OF 3d,4d AND 5d ELEMENTS
PRESENTED BY
ARUN CHIKKODI.
M.Sc., II semester
Department of Chemistry.
Jnana Sahyadri, Shankaraghatta

2. CONTENTS
 Introduction.
 Comparative study of 3d 4d and 5d elements.
Ionic radius
Oxidation state
Magnetic properties
Metal metal bonding
Coordination number of complexes
Abundance
conclusion

3. INTRODUCTION
• The elements which have partly filled d subshell are called d block
elements.
• They are also called transition elements as their properties are partly
of s-block and partly of p-block elements
• These d block elements include three complete series
I,e.,3d,4d,&5d., whereas one incomplete series 6d.
• The 4d and 5d transition series elements have similar characteristics
, but show typical differences from 3d series.

4. Sc Ti V Cr Mn Fe Co Ni Cu Zn
Y Zr Nb Mo Tc Ru Rh Pd Ag Cd
La Hf Ta W Re Os Ir Pt Au Hg
3d series
4d series
5d series
d- block elements

5. COMPARATIVE STUDY OF 3d,4d
AND 5d ELEMENTS

6. IONIC RADIUS
• On moving down a group in a periodic table ,the ionic radii of the
elements increases.
• The 4d elements are larger in size as compared to the 3d elements.
Because of increase in the number of electrons and higher principal
quantum numbers of elements.
• There is very little differences in ionic radii of the elements of 4d and
5d series due to lanthanide contraction.

7. 0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
0 2 4 6 8 10 12
atomicradius
increasing atomic number
Ionic radius of d block elements
4d series
5d series
3d series

8. OXIDATION STATE
• The 4d and 5d elements exist higher oxidation states than 3d
elements because they have low ionization energy.
• Higher oxidation state is generally more stable.
• Example: RuO4, WCl6, PtF6 are stable.
• [MoO4]2- and [WO4]2- are highly stable and are not easily reduced.
Where as [CrO4]2- is a very strong oxidising agent and is easily
reduced.

9. MAGNETIC PROPERTIES
• According to Crystal field theory ,d orbitals in complexes splits into t2g
and eg sublevels.
• The magnitude of splitting for any given ligand is greater for 4d and
5d members than 3d elements.
• So these metals form predominantly spin paired complexes.
• Even the weaker ligand the complexes are diamagnetic in nature.
• The 3d elements form spin – free, paramagnetic complexes with weak
ligands.

10. METAL-METAL BONDING
• The 4d and 5d elements have a greater tendency to form metal-
metal bonds compare to 3d elements.
• As a result a large number of polynuclear and cluster compounds
are known.
• Examples : [Re2Cl8]2- , [Mo2Cl9]3-, [Rh4(CO)12] and [Ir4(CO)12].

11. COORDINATION NUMBER OF COMPLEXES
• For the 3d series metals , complexes with co –ordination number 6
are most common.
• The 4d and 5d elements are larger in size and can accommodate a
larger number of ligands around them.
• Therefore the 4d and 5d elements form complexes with co-ordination
number greater than 6.
• Examples: [Na3(ZrF7)] and [Cu2(ZrF8)].

12. ABUNDANCE
• The 3d series transition metals are more abundant in the earth’s
crust as compared to the heavier elements.
• The first series constitute about 6.8% of the earth’s crust.
• The second and third series constitute only 0.025% of the earth’s
crust.
• The element technetium does not exits in nature.

13. CONCLUSION
• The 4d elements are larger in size as compared to 3d elements.
• The 4d and 5d elements exists higher oxidation state than 3d
elements.
• The 3d elements forms paramagnetic complexes whereas 4d and 5d
elements forms diamagnetic complexes.

14. REFERENCES
• Principles of Inorganic Chemistry, B.R. Puri, L.R. Sharma, K.C.
Kalia, Milestone Publishers, New Delhi, India, 2008.
• Page number- 716-718
• Concise Inorganic Chemistry, 5th Edition, J.D. Lee, Blackwell
Science Ltd., London, 2003.
• Page number- 674-676
• Internet source