Graduate
  1. Physical Chemistry  1.1. Thermodynamics  1.1.1. Laws of Thermodynamics  1.1.2. Enthalpy and heat capacity  1.1.3. Entropy and free energy  1.1.4. Phase Equilibrium  1.1.5. Statistical thermodynamics  1.1.6. Thermodynamic cycle  1.1.7. Fugacity and activity  1.2. Quantum Chemistry  1.2.1. Principles of quantum mechanics  1.2.2. Schrödinger Equation  1.2.3. Particle in a box  1.2.4. Operators and eigenvalues  1.2.5. Atomic orbitals  1.2.6. Molecular orbital theory  1.2.7. Perturbation theory  1.2.8. Valence bond theory  1.2.9. Hybridization and chemical bonding  1.3. Chemical kinetics  1.3.1. Rate laws and reaction mechanisms  1.3.2. Collision theory  1.3.3. Transition state theory  1.3.4. Enzyme Kinetics  1.3.5. Chain Reactions and Polymerization  1.3.6. Photochemical reactions  1.4. Statistical mechanics  1.4.1. Partitioning functions  1.4.2. Molecular distribution functions  1.4.3. Boltzmann Distribution  1.4.4. Bose–Einstein and Fermi–Dirac statistics  1.5. Spectroscopy  1.5.1. Rotational Spectroscopy  1.5.2. Vibrational Spectroscopy  1.5.3. Electronic Spectroscopy  1.5.4. Nuclear magnetic resonance spectroscopy  1.5.5. Mass Spectrometry  1.5.6. Raman Spectroscopy  1.5.7. Electron paramagnetic resonance spectroscopy  1.6. Surface and colloidal chemistry  1.6.1. Absorption isotherm  1.6.2. Surface tension and wetting  1.6.3. Colloidal Stability  1.6.4. Catalysis  1.6.5. Emulsions and micelles  1.7. Electrochemistry  1.7.1. Nernst equation  1.7.2. Electrochemical cells  1.7.3. Conductivity and mobility  1.7.4. War  1.7.5. Fuel cells  1.7.6. Electrolysis
  2. Organic chemistry  2.1. Reaction mechanism  2.1.1. Nucleophilic substitution reactions  2.1.2. Electrophilic addition reactions  2.1.3. Elimination reactions  2.1.4. Rearrangement reactions  2.1.5. Radical reactions  2.1.6. Pericyclic reactions  2.2. Spectroscopy and structural determination  2.2.1. UV-Vis Spectroscopy  2.2.2. IR Spectroscopy  2.2.3. NMR Spectroscopy  2.2.4. Mass Spectrometry  2.2.5. X-ray crystallography  2.3. Stereoscopic  2.3.1. Chirality and optical activity  2.3.2. Structural analysis  2.3.3. Geometrical isomerism  2.3.4. Dynamic Stereochemistry  2.4. Organometallic Chemistry  2.4.1. Organolithium and organomagnesium reagents  2.4.2. Palladium-catalyzed cross-coupling reactions  2.4.3. Transition Metal Complexes  2.4.4. Metal–carbon bond  2.5. Polymer chemistry  2.5.1. Polymerization mechanism  2.5.2. Polymer Characteristics  2.5.3. Biodegradable Polymer  2.5.4. Conducting polymer  2.5.5. Supramolecular polymers  2.6. Medicinal chemistry  2.6.1. Drug design and development  2.6.2. Pharmacokinetics and pharmacodynamics  2.6.3. Structure-activity relationships  2.6.4. Molecular docking and drug screening
  3. Inorganic chemistry  3.1. Coordination chemistry  3.1.1. Crystal field theory  3.1.2. Ligand field theory  3.1.3. Spectrochemical Series  3.1.4. Chelation and stability  3.2. Organometallic Chemistry  3.2.1. Metal Carbonyls  3.2.2. Catalysis by organometallic complexes  3.2.3. Metallocenes  3.3. Bio-inorganic chemistry  3.3.1. Metalloproteins and enzymes  3.3.2. The role of metals in biological systems  3.3.3. Metal ion transport and storage  3.4. Solid state chemistry  3.4.1. Crystal Structures  3.4.2. Band theory of solids  3.4.3. Superconductors  3.4.4. Defects in the crystal  3.5. Lanthanides and Actinides  3.5.1. Electronic configuration in lanthanides and actinides  3.5.2. Coordination chemistry of the lanthanides  3.5.3. Magnetic Properties of Lanthanides
  4. Analytical chemistry  4.1. Chromatography  4.1.1. Gas Chromatography  4.1.2. High Performance Liquid Chromatography  4.1.3. Thin Layer Chromatography  4.2. Spectroscopic Techniques  4.2.1. Atomic absorption spectroscopy  4.2.2. X-ray diffraction  4.2.3. Inductively coupled plasma spectroscopy  4.3. Electroanalytical methods  4.3.1. Potentiometry  4.3.2. Voltammetry  4.3.3. Colometry  4.4. Mass Spectrometry  4.4.1. Ionization Technique  4.4.2. Fragmentation Pattern  4.5. Chemometrics  4.5.1. Multidisciplinary analysis  4.5.2. Machine Learning in Chemistry
  5. Theoretical and Computational Chemistry  5.1. Molecular dynamics simulation  5.1.1. Force fields and energy minimization  5.1.2. Monte Carlo simulation in molecular dynamics simulations  5.2. Quantum chemical methods  5.2.1. Hartree–Fock theory  5.2.2. Density functional theory  5.2.3. Semi-empirical methods  5.3. Computational drug design  5.3.1. Molecular Docking  5.3.2. QSAR Modeling  5.3.3. Virtual Screening
  6. Biochemistry  6.1. Enzyme Kinetics  6.1.1. Michaelis-Menten kinetics  6.1.2. Inhibition mechanism  6.2. Metabolism and Bioenergetics  6.2.1. Glycolysis  6.2.2. Citric acid cycle  6.2.3. Electron transport chain  6.3. molecular Biology  6.3.1. DNA replication and repair  6.3.2. Protein synthesis  6.3.3. Gene Regulation  6.4. Structural Biochemistry  6.4.1. Protein Folding  6.4.2. Membrane Biophysics
  7. Environmental Chemistry  7.1. Atmospheric Chemistry  7.1.1. Greenhouse gases  7.1.2. Ozone depletion  7.1.3. Air pollutants and smoke  7.2. Water Chemistry  7.2.1. pH and water hardness  7.2.2. Wastewater treatment  7.2.3. Aquatic Chemistry  7.3. Soil Chemistry  7.3.1. Heavy metal contamination  7.3.2. Soil pH and Buffering  7.3.3. Nutrient cycling  7.4. Toxicology and Chemical Safety  7.4.1. Toxicokinetics  7.4.2. Risk Assessment in Toxicology and Chemical Safety in Environmental Chemistry  7.4.3. Effects of pollutants on the environment

Graduate → Organic chemistry ↓


Organometallic Chemistry


Organometallic chemistry is an interdisciplinary field that combines organic chemistry with inorganic chemistry. It involves the study of chemical compounds containing bonds between carbon and metal. These metal atoms can include a wide range of elements, but transition metals are the most studied due to their wide range of applications and unique properties. Organometallic compounds play an important role in both industrial processes and the development of new materials and chemicals.

Definition and scope

Organometallic compounds are characterized by the presence of at least one bond between a carbon atom of an organic molecule and a metal. These compounds can be represented by the general formula RM, where R is an organic group, and M is a metal. The metals involved can be from almost all groups of the periodic table, including main group elements like aluminum or tin, transition metals like iron, palladium and platinum, and even lanthanides and actinides.

History and development

The history of organometallic chemistry dates back to the 18th century, although major developments occurred in the 19th and 20th centuries. One of the earliest organometallic compounds, known as Zeise's salt (potassium trichloro(ethylene)platinate(II)), was synthesized in 1827 and paved the way for further studies. In the 20th century, the discovery of ferrocene [Fe(C 5 H 5 ) 2 ] ushered in a new era in organometallic chemistry, opening the door to new research in the field of sandwich compounds.

Structure and relationships

The structure and bonding in organometallic compounds are diverse and depend heavily on the nature of the metal and the organic groups attached to it. Bonds between carbon and metals can range from highly ionic to covalent. The metal's electron configuration, size, oxidation state, and coordination preferences all affect the nature of these bonds.

Covalent and ionic bonds

For main group metals, covalent bonding is prevalent. However, transition metals interact with carbon in a more complex manner via d-orbitals. Transition metal organometallic compounds can exhibit synergistic bonding where the metal donates electron density into the π-orbitals of the ligand while simultaneously receiving electron density into its d-orbitals in a back-donation mechanism.

[ML n ]

Example: Ferrocene

Ferrocene is a classic example of an organometallic compound with a "sandwich" structure.

[Fe(η 5 -C 5 H 5 ) 2 ] [Fe(η 5 -C 5 H 5 ) 2 ]

In ferrocene, the iron atom is sandwiched between two cyclopentadienyl rings. This interaction involves η 5 bonding, which means that each C 5 H 5 ring donates five electrons from its π-system to the metal.

This configuration results in a strong and stable compound, which is typical of cyclopentadienyl metal complexes.

Types of organometallic compounds

Organometallic compounds are classified based on the type of metal-carbon bond present in them:

  • Covalent organometallic compounds: These contain predominantly covalent bonds, such as compounds based on metals such as lithium, magnesium, and aluminum.
  • Migratory insertion compounds: These involve the migration of a σ-bonded ligand such as a hydride or alkyl group to an adjacent coordinated unsaturated ligand.
  • π-Complexes: Compounds in which the metal is coordinated with the π-electrons of an unsaturated molecule, such as alkenes, alkynes, and arenes.

Synthesis of organometallic compounds

Several methods are used to prepare organometallic compounds:

Direct synthesis

This involves the reaction between a metal and an organic halide or another organic compound. For example, the Grignard reagent RMgX is made by refluxing magnesium with an alkyl or aryl halide.

Transmetalation

This method involves transferring a metal from one organometallic framework to another, often using salts of the other metal.

Reductive coupling

This process involves the coupling of two organic groups in the presence of a reducing metal, forming a metal-organometallic compound.

Example: Grignard reaction

The Grignard reaction is a classic example of organometallic synthesis in organic chemistry.

The reaction is as follows:

R-Br + Mg → R-Mg-Br

Where R is an alkyl group and Br is a halogen.

Applications of organometallic compounds

Organometallic chemistry has wide applications in various fields:

  • Catalysis: Organometallic catalysts are used in many industrial processes. These chemicals allow reactions to occur under mild conditions and increase the selectivity of the result. For example, Ziegler-Natta catalysts are used in the polymerization of ethylene and propylene.
  • Medicine: Some organometallic compounds have been developed for medicinal uses, such as cisplatin, which is an effective anti-cancer drug.
  • Materials science: Organometallics are essential in the synthesis of electronics and advanced materials.

For catalytic processes, a classic example is the olefin polymerization catalyzed by titanium-aluminum alkyls, known as Ziegler-Natta catalysts:

The simplified reaction involves:

[TiCl 4 ] + Al(C 2 H 5 ) 3 → Active catalytic species

The addition of ethylene results in the formation of polyethylene:

n(CH 2 =CH 2 ) → -[CH 2 CH 2 ] n -

Challenges and protection

Despite their applications, organometallic compounds often present handling and stability challenges. Some are highly reactive, air-sensitive, or toxic. Appropriate precautions must be taken during their synthesis and handling, such as working under inert atmosphere conditions (e.g., nitrogen or argon). Appropriate protective equipment and protocols are essential for safe laboratory practices.

Future directions

The science of organometallic chemistry is continually evolving, with research focused on developing new compounds and catalytic processes that are more sustainable, efficient, and applicable to complex systems such as those found in biological organisms. Progress is also being made in understanding and using abundant metals on Earth to reduce dependence on expensive and rare metals.

In short, organometallic chemistry serves as an important bridge between organic and inorganic chemistry. It opens a versatile toolbox for chemists to explore bond formation and reactivity, opening up diverse applications ranging from industrial synthesis to the development of new materials and therapeutic agents.


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Organometallic Chemistry

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