PHD
  1. Inorganic chemistry  1.1. Coordination chemistry  1.1.1. Ligand field theory  1.1.2. Crystal field theory  1.1.3. Molecular Orbital Theory for Coordination Compounds  1.1.4. Stability of Coordination Compounds  1.1.5. Electronic spectra of coordination compounds  1.1.6. Isomerism in Coordination Compounds  1.1.7. Kinetics and mechanism of coordination reactions  1.2. Organometallic Chemistry  1.2.1. Metal Carbonyls  1.2.2. Metal alkyl and aryl  1.2.3. Fischer and Schrock carbonaceans  1.2.4. Oxidative Addition and Reductive Elimination  1.2.5. Metal Hydrides  1.2.6. Catalysis by organometallic compounds  1.2.7. Metallocenes and Sandwich Complexes  1.2.8. CH activation  1.3. Solid state chemistry  1.3.1. Crystal structures and lattices  1.3.2. Band theory and electrical properties  1.3.3. Defects in the crystal  1.3.4. Synthesis of solid state materials  1.3.5. Magnetic and optical properties of solids  1.3.6. Superconductivity  1.3.7. Solid state ionics  1.4. Bio-inorganic chemistry  1.4.1. Metalloproteins and enzymes  1.4.2. Metal ion transport and storage  1.4.3. The role of metals in medicine  1.4.4. Bioinspired catalysis  1.4.5. Metal–DNA interactions  1.4.6. Metal Complexes in Medical Science  1.5. Lanthanides and Actinides  1.5.1. Electronic configuration and oxidation states in lanthanides and actinides  1.5.2. Spectral and Magnetic Properties in Lanthanides and Actinides  1.5.3. Separation and Extraction of Lanthanides and Actinides  1.5.4. Coordination chemistry of f-block elements  1.6. Main Group Chemistry  1.6.1. Chemistry of boron compounds  1.6.2. Chemistry of Silicon and Germanium Compounds  1.6.3. Chemistry of Phosphorus and Sulfur Compounds  1.6.4. Organosilicon chemistry  1.6.5. Noble Gas Chemistry
  2. Organic chemistry  2.1. Reaction mechanism  2.1.1. Nucleophilic substitution reactions  2.1.2. Electrophilic addition and substitution reactions  2.1.3. Elimination reactions  2.1.4. Rearrangement reactions  2.1.5. Radical reactions  2.1.6. Pericyclic Reactions  2.1.7. Photochemical reactions  2.2. Stereoscopic  2.2.1. Chirality and optical activity  2.2.2. Structural analysis  2.2.3. Stereoelectronic effects  2.2.4. Asymmetric synthesis  2.2.5. Dynamic Stereochemistry  2.3. Organometallic Chemistry in Organic Synthesis  2.3.1. Organolithium and organomagnesium reagents  2.3.2. Transition metal catalyzed coupling reactions  2.3.3. Palladium-catalyzed reactions  2.3.4. Olefin Metathesis  2.3.5. Gold and silver catalysis  2.4. Natural products chemistry  2.4.1. Alkaloids and terpenoids  2.4.2. Steroids and Flavonoids  2.4.3. Total synthesis of natural products  2.4.4. Biosynthesis of natural products  2.5. Supramolecular Chemistry  2.5.1. Host-Guest Chemistry  2.5.2. Self-assembly and molecular recognition  2.5.3. Supramolecular Catalysis  2.5.4. Molecular Machines
  3. Physical Chemistry  3.1. Thermodynamics  3.1.1. Laws of Thermodynamics  3.1.2. Chemical Potential and Equilibrium  3.1.3. Statistical thermodynamics  3.1.4. Non-equilibrium thermodynamics  3.2. Quantum Chemistry  3.2.1. Schrödinger equation and its applications  3.2.2. Molecular orbital theory  3.2.3. Density functional theory  3.2.4. Post-Hartree–Fock methods  3.3. Chemical kinetics  3.3.1. Reaction rate theory  3.3.2. Mechanism and rate laws  3.3.3. Catalysis and enzyme kinetics  3.3.4. Reaction dynamics  3.4. Spectroscopy and molecular structure  3.4.1. Infrared Spectroscopy  3.4.2. UV-visible spectroscopy  3.4.3. Nuclear Magnetic Resonance Spectroscopy  3.4.4. Mass Spectrometry  3.4.5. Raman Spectroscopy  3.5. Surface and Colloid Chemistry  3.5.1. Absorption and Catalysis  3.5.2. Surfactants and micelles  3.5.3. Colloidal Stability  3.5.4. Nanomaterials and Interfaces
  4. Analytical chemistry  4.1. Chromatography  4.1.1. Gas Chromatography  4.1.2. High Performance Liquid Chromatography  4.1.3. Thin Layer Chromatography  4.1.4. Ion Chromatography  4.2. Electroanalytical techniques  4.2.1. Voltammetry and Polarography  4.2.2. Conductometry and potentiometry  4.2.3. Colometry  4.3. Spectroscopic Methods  4.3.1. Atomic absorption spectroscopy  4.3.2. Fluorescence Spectroscopy  4.3.3. X-ray diffraction  4.3.4. Electron paramagnetic resonance spectroscopy  4.4. Chemometrics  4.4.1. Data processing and statistical methods  4.4.2. Multidisciplinary analysis  4.4.3. Machine Learning in Analytical Chemistry
  5. Theoretical and Computational Chemistry  5.1. Molecular dynamics simulation  5.2. Quantum chemistry methods  5.3. Computational drug design  5.4. Machine Learning in Chemistry  5.5. Ab initio molecular dynamics
  6. Biophysics and Medicinal Chemistry  6.1. Drug discovery and design  6.2. Enzyme kinetics and inhibition  6.3. Chemical biology approach  6.4. Protein-ligand interactions  6.5. Bioorthogonal chemistry
  7. Materials chemistry  7.1. Polymer chemistry  7.1.1. Polymerization mechanism  7.1.2. Functional Polymers  7.1.3. Biodegradable Polymer  7.1.4. Conducting and semiconducting polymers  7.2. Nano Chemistry  7.2.1. Nanoparticles and nanostructures  7.2.2. Carbon-based nanomaterials  7.2.3. Quantum dots  7.3. Energy and Environmental Chemistry  7.3.1. Battery and Fuel Cell Chemistry  7.3.2. Green chemistry and sustainable materials  7.3.3. Photocatalysis

PHD → Inorganic chemistry → Lanthanides and Actinides ↓


Electronic configuration and oxidation states in lanthanides and actinides


The lanthanides and actinides, known as the f-block elements, are a fascinating group within the periodic table. These blocks occupy the 6th and 7th periods and are often displayed separately at the bottom of the periodic table due to their unique electronic configurations and distinctive oxidation states.

Electronic configuration of lanthanides

The lanthanides contain 15 elements, ranging from lanthanum (La) to lutetium (Lu). The electronic configuration of the lanthanides can generally be represented by the formula:

[Xe] 4f 1-14 5d 0-1 6s 2

The filling of electrons in the 4f subshell is the defining feature of the lanthanides. Unlike other elements, where added electrons often significantly alter chemical properties, the lanthanides maintain fairly uniform chemical behavior throughout. As we move up the series, electrons fill 4f orbitals, which are deeply embedded and are less influential when it comes to detecting chemical properties.

4F 5 days 6S

Consider an example, the electronic configuration of cerium (Ce) is:

[Xe] 4f 1 5d 1 6s 2

As we add electrons to the 4f orbitals, the electronic configuration changes, leading to a normal increase in atomic number without appreciable change in chemical properties.

Oxidation states of lanthanides

Most lanthanides typically have a +3 oxidation state. This comes primarily from the loss of 3 electrons from the 6s and 4f orbitals, creating the typical +3 oxidation state:

Ln → Ln 3+ + 3e -

However, some lanthanides also have +2 and +4 oxidation states, although they are less stable. For example, europium (Eu) shows a +2 oxidation state, and cerium can attain a +4 state. This variability in oxidation states is due to the close energy levels of the 4f, 5d, and 6s orbitals.

An example of europium oxidation state is:

Eu → Eu 2+ + 2e - (reduced state)

Found in the same region of the periodic table, the actinides share some characteristics with the lanthanides, but also display unique features.

Electronic configuration of actinides

The actinides, which include elements from actinium (Ac) to lawrencium (Lr), fill f-orbitals in a similar way. However, here it is a 5f subshell:

[Rn] 5f 1-14 6d 0-1 7s 2

Unlike the lanthanides, the actinides have more variable electron filling, involving both the 5f and 6d orbitals. Additionally, they can have a wider range of oxidation states, primarily due to the significant involvement of the 5f electrons in bonding.

5F 6 days 7s

As an example, consider uranium (U), which has the electronic configuration as follows:

[Rn] 5f 3 6d 1 7s 2

The 5f orbitals in the actinides are relatively more exposed than the 4f orbitals in the lanthanides, because of their spatial shape, allowing for a variety of bonding and oxidation states.

Oxidation states of actinides

The actinides display a greater variety of oxidation states than the lanthanides. While the +3 oxidation state is still common, +4, +5, +6, and +7 can also occur. Higher oxidation states are possible due to the ability of the actinides to use their 5f, 6d, and 7s electrons in bonding.

For example, uranium exhibits +3, +4, +5, and +6 oxidation states. The +6 state is dominant, as seen in the uranyl ion (UO 2 2+ ).

U → UO 2 2+ (in aqueous solution)

The tendency of actinides to have multiple oxidation states contributes to their complex chemistry, providing rich areas for research and industrial applications, especially nuclear energy.

Comparison between lanthanides and actinides

In summary, while both lanthanides and actinides fill f-orbitals, actinides have different chemical behaviors due to the involvement of their 5f orbital in bonding. Lanthanides are limited to +3 oxidation states with similar properties throughout the series, while actinides offer a range of oxidation states from +3 to +7, which greatly affect their reactivity and chemical pathways.

The unique properties of these elements present both challenges and opportunities in their use for scientific and practical applications, reflecting the continued interest in the study and application of f-block elements within the science community.

Although the electronic configurations of the lanthanides and actinides can be complex, they provide a fundamental understanding of these elements to support further exploration in advanced inorganic chemistry, nuclear science, and materials science.


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Electronic configuration and oxidation states in lanthanides and actinides

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