Consequences of Lanthanide Contraction
The lanthanide contraction is a phenomenon that occurs in the lanthanide series, where the atomic and ionic radii of the elements decrease as the atomic number increases. The effects of the lanthanide contraction are:
- Atomic Size: The atomic size of the elements in the lanthanide series decreases as the atomic number increases, resulting in a smaller atomic radius.
- Difficulty in Separation: The slight change in ionic radii of the lanthanides makes their separation challenging.
- Effect on Basic Strength of Hydroxides: The hydroxides’ covalent character increases as the lanthanides’ size decreases from La to Lu.
- Complex Formation: The lanthanide contraction affects the formation of complexes, as the smaller size of the ions can lead to stronger bonding.
- Ionization Energy: The lanthanide contraction significantly affects the ionization energy of the lanthanide series. The ionization energy increases as the atomic and ionic radii decrease due to the lanthanide contraction.
- Impact on coordination number: The lanthanide contraction decreases coordination number as one moves down the series. For example, lanthanide ions smaller than La form higher coordination numbers, such as 11-coordinate structures, while those with larger lanthanide ions may form lower coordination numbers.
- Ions in crystal lattices: The lanthanide contraction profoundly impacts the crystal structures and properties of compounds containing lanthanide ions, leading to a wide variation in crystal structures and increased symmetry around the lanthanide ions in crystal lattices.
Lanthanide Contraction
Lanthanide Contraction is a phenomenon that describes the steady decrease in the size of the atoms and ions of the rare-earth elements as the atomic number increases. The lanthanide contraction is a significant factor in the close chemical similarity of the rare-earth elements and affects the properties of the post-lanthanide elements. This phenomenon has implications for various properties, such as atomic size, density, and chemical reactivity.
Table of Content
- What is Lanthanide?
- What is Lanthanide Contraction?
- Consequences of Lanthanide Contraction
- Cause of Lanthanide Contraction
- Electronic Configuration of Lanthanide