Organic Chemistry

History of Organic Chemistry

• Pre-1600s: Alchemy led to pure compound production and invention of laboratory tools.
• 1300s-1500s: Fractionation of alcoholic distillates; isolation of organic compounds like acetic and formic acid.
• 1600s-1700s: Birth of modern chemistry; distinction between organic (from living organisms) and inorganic compounds established.
• Key Figures:
  • Torbern Bergman differentiated organic and inorganic substances.
  • Hilaire Rouelle isolated urea from human urine.
  • Antoine Lavoisier created the first table of elements and defined organic compounds.
  • Jons Jakob Berzelius proposed the vitalistic theory of organic chemistry.
• 1800s:
  • Michel Chevreul produced soap from animal fat and alkali.
  • Friedrich Wöhler synthesized urea from ammonium cyanate, marking a significant moment in organic chemistry.
  • William Brande mentioned the blurred lines between organic and inorganic chemistry.
  • Edward Frankland advanced the concept of valence.

Organic Chemistry Defined

• Focuses on carbon compounds due to their unparalleled chemical diversity.
• Carbon can form four strong covalent bonds, enabling complex structures.

Atomic Structure

• Nucleus: Composed of protons (positive charge) and neutrons (neutral charge); contains most of an atom's mass.
• Subatomic Particle Mass: Proton (1.007), Neutron (1.009), Electron (5.486 x 10^-4).
• Isotopes: Atoms with the same atomic number but different mass numbers.
• Atomic Weight: Weighted average of an element's naturally occurring isotopes.

Electron Configuration

• Quantum Mechanical Model: Electrons are described by wave functions (orbitals), indicating the probability of their location.
• Orbitals Types: s, p, d, f; each has distinct shapes and energy levels.
• Electron Shells: Organized layers around the nucleus containing orbitals with varying energy and types.

Molecular Spectroscopy

• Modern tools for structural determination:
  • Mass Spectroscopy (MS)
  • Infrared Spectroscopy (IR)
  • Nuclear Magnetic Resonance Spectroscopy (NMR)
  • Ultraviolet Spectroscopy (UV)

Functional Groups

• Atoms/groups responsible for characteristic chemical behavior in compounds.
• Compounds can be monofunctional, difunctional, or polyfunctional.

Classes of Organic Compounds

• Groups of carbon atoms covalently bonded to hydrogen and other elements.
• Examples include:
  • Alkyl halide
  • Amine
  • Ketone
  • Aromatic hydrocarbon
  • Alkene
  • Carboxylic acid
  • Alcohol
  • Alkyne
  • Alkane

Isomerism

• Isomers have the same molecular formulas but different atom arrangements.
• Types of Isomers:
  • Conformational Isomers: Different arrangements due to rotation around single bonds.
  • Structural Isomers: Different connectivity between atoms.
  • Stereoisomers: Same connectivity but different spatial arrangements.
  • Geometric (Cis/Trans) Isomers: Differ in spatial arrangements around a double bond.
  • Optical Isomers (Enantiomers): Non-superimposable mirror images; chiral carbons have four unique groups.
  • Diastereomers: Non-mirror image stereoisomers.

Conclusion

• Organic chemistry is fundamental in understanding the composition of living organisms and synthesizing new compounds.

History of Organic Chemistry

Pre-1600s

• Alchemy practices led to the production of pure compounds and the invention of laboratory tools (beakers, flasks, crucibles).
• Techniques included distillation, laying groundwork for modern chemistry.

1300s-1500s

• Fractionation of alcoholic distillates like whisky and brandy.
• Isolation of organic compounds such as acetic acid from vinegar and formic acid from ants for medicinal use.

1600s-1700s

• Emergence of chemistry as a scientific discipline in Europe.
• Torbern Bergman distinguished organic compounds (from living organisms) from inorganic compounds (from mineral sources).
• Hilaire Rouelle isolated urea from human urine.
• Antoine Lavoisier established foundational concepts of modern chemistry, illustrating organic compounds' composition of C, H, N, and P.
• Jons Jakob Berzelius proposed the vitalism theory, linking organic compounds to life forces.

1800s

• Michel Chevreul produced soap from alkali and animal fat, leading to the isolation of fatty acids.
• Friedrich Wöhler synthesized urea from ammonium cyanate, marking a milestone in organic chemistry as he did not require biological sources.
• William Brande suggested that distinctions between organic and inorganic chemistry were largely practical.
• Adolph Kolbe synthesized acetic acid, contributing to organic synthesis techniques.

19th Century

• Edward Frankland introduced the concept of valence, essential for understanding bonding.
• Stanislao Cannizzaro utilized Avogadro’s hypothesis to determine accurate molecular weights.
• A. Kekule and A. Cooper advanced structural formulas, depicting tetravalency of carbon.
• Emil Erlenmeyer proposed multiple bonding concepts, such as acetylene.
• J.van’t Hoff and J.LeBel introduced three-dimensional molecular views.

20th Century

• Modern developments in chemical bonding, including ionic bonding (W.Kossel) and covalent bonding (G.N.Lewis).
• Quantum mechanical models helped in understanding atomic structure and bonding principles.

Overview of Organic Chemistry

• Organic chemistry studies carbon compounds which exhibit unmatched diversity due to carbon's ability to form multiple strong covalent bonds.
• Significant carbon compounds include those in living organisms: proteins, DNA, and many medicines.
• Carbon's special properties stem from its electronic structure, enabling it to bond in myriad forms including chains and rings.

Atomic Structure and Bonding

• The nucleus contains protons (positive charge) and neutrons (neutral), contributing nearly all atomic mass.
• Electrons are organized in orbitals, which shape the chemical properties of elements.
• Different types of orbitals (s, p, d, f) accommodate varying numbers of electrons.
• Electron configurations follow Aufbau's principle, Pauli exclusion principle, and Hund’s rule for arrangement in atoms.

Organic Compounds

• Organic compounds are primarily groups of carbon atoms bonded to hydrogen, oxygen, and other elements.
• Organic analysis has significantly improved understanding of molecular structures and reactions, constituting the foundation of organic chemistry.

Conclusion

• The field has evolved from alchemical practices to sophisticated organic synthesis.
• Ongoing research and development expand the realm of organic compounds, enhancing fields like medicine, materials science, and environmental chemistry.

Birth of Organic Chemistry

• Distinctions in organic chemistry serve practical purposes to facilitate student learning.
• Adolph Wilhelm Hermann Kolbe is known for Acetic Acid synthesis in the 1840s.
• Edward Frankland advanced the concept of valence (Latin for "power") in 1852.
• Stanislao Cannizzaro utilized Avogadro’s hypothesis to accurately determine molecular weights in 1858.
• A. Kekulé and A. Cooper proposed structural formulas demonstrating tetravalency of carbon during 1850-1860.
• Emil Erlenmeyer proposed concepts of multiple bonding such as acetylene.
• Kekulé proposed that carbon chains can double back to form rings of atoms.
• J. van’t Hoff and J. LeBel developed three-dimensional views of molecules.

Modern Concepts of Chemical Bonding

• Ionic bonding was defined by W. Kossel, while covalent bonding concepts were developed by G.N. Lewis in 1916.
• Quantum mechanical models of the atom were formulated by Dirac and Heisenberg, shaping understanding of chemical bonding.

Organic Chemistry Overview

• Organic chemistry focuses on carbon compounds due to carbon's unmatched chemical diversity.
• Key reasons for carbon's diversity include strong bonding capabilities with itself and other elements.
• Carbon forms a high number of covalent bonds (four), making organic compounds primarily covalent.
• Compounds with carbonate ions, bicarbonates, carbon dioxide, and carbon monoxide are not classified as organic.

Mass and Structure of Atoms

• Nucleus holds most of an atom's mass.
• Proton: Relative charge 1, mass 1.007
• Neutron: Relative charge 0, mass 1.009
• Electron: Relative charge -1, mass approximately 0.0005
• Isotopes have the same atomic number but different mass numbers.

Quantum Mechanical Model and Orbitals

• Electrons are distributed around the nucleus according to quantum mechanics, represented as wave functions or orbitals (ψ).
• Orbitals indicate where an electron is likely to be found 90-95% of the time.
• Four types of orbitals exist: s, p, d, and f, each with unique shapes and arrangements.
• Electron shells group orbitals and have increasing size and energy levels.

Electron Configuration Rules

• Aufbau principle states that the lowest-energy orbitals fill first.
• Pauli exclusion principle dictates that no more than two electrons occupy an orbital, with opposite spins.
• Hund’s rule emphasizes that electrons will fill empty orbitals singly before pairing.

Modern Methods in Organic Analysis

• Organic analysis combines historical methods (Lavoisier, Dumas, von Liebig) with modern techniques.
• Methods include combustion experiments, empirical formula analysis, and microanalysis using mass spectroscopy.

Structural Features of Organic Compounds

• Organic compounds typically consist of carbon atoms covalently bonded to hydrogen, oxygen, and other elements.
• Functional groups determine the characteristic behaviors of organic compounds, with examples including amines, carboxylic acids, and alcohols.

Classes of Organic Compounds

• Compounds can be classified based on functional groups and structural characteristics.
• Categories include alkyl halides, ketones, aromatic hydrocarbons, alkenes, alkynes, and alkanes, among others.

Isomerism

• Isomers are compounds that share the same atomic composition but differ in spatial arrangement or structural configuration.
• Isomerism contributes to the complexity and diversity of organic compounds, influencing their properties and reactivity.

History of Organic Chemistry

• Pre-1600’s: Alchemy practices established processes for producing pure compounds and developing laboratory tools such as beakers, flasks, and distillation apparatus.

1300’s-1500’s

• Introduction of alcoholic distillation, leading to the production of whisky and brandy.
• Isolation of pure organic compounds like acetic acid (from vinegar) and formic acid (from ants) for medicinal purposes.

1600’s-1700’s

• Birth of modern chemistry in Europe, distinguished organic from inorganic chemistry.
• Torbern Bergman (1770): Defined organic compounds as derived from living matter, unable to follow the Law of Definite Proportions while inorganic compounds are derived from minerals and the atmosphere.
• Hilaire Rouelle (1780): Isolated urea from human urine.
• Antoine Lavoisier (1789): Created a table of 33 elements; emphasized that organic compounds consist of carbon (C), hydrogen (H), and sometimes nitrogen (N) and phosphorus (P).
• Jons Jakob Berzelius (1789): Proposed the vitality theory, claiming a vital force in living organisms responsible for producing organic compounds.

1800’s

• Michel Chevreul (1816): Produced soap by reacting alkali with animal fat, separating it into pure fatty acids.
• Friedrich Wöhler (1828): Synthesized urea from ammonium cyanate, marking the first multi-step transformation and is considered the father of organic chemistry.
• William Brande (1848): Asserted that the distinction between organic and inorganic chemistry is practical and not absolute.
• Adolph Wilhelm Hermann Kolbe (1840’s): Developed a synthesis for acetic acid.

19th Century

• Edward Frankland (1852): Advanced the concept of valence, akin to atomic bonding power.
• Stanislao Cannizzaro (1858): Utilized Avogadro’s hypothesis for accurately determining molecular weights.
• A. Kekulé & A. Cooper (1850-1860): Proposed the tetravalency of carbon and developed structural formulas.
• Emil Erlenmeyer (1850-1860): Introduced concepts of multiple bonding, such as in acetylene.
• Vision of carbon chains forming rings known as “Kekulé’s Dream.”

20th Century

• Development of ionic bonding (W. Kossel) and covalent bonding (G. N. Lewis).
• Quantum Mechanical Model: Transformed understanding of atomic structure and bonding.

Fundamentals of Organic Chemistry

• Organic chemistry is primarily the study of carbon compounds, selected for its unmatched chemical diversity.
• Unique capabilities of carbon include the formation of robust bonds with itself and other elements, leading to diverse compounds.

Atomic Structure Overview

• Nucleus: Comprises protons (positive charge) and neutrons (neutral charge); holds most of an atom’s mass.
• Subatomic Particle Masses: Protons (1.007), Neutrons (1.009), Electrons (5.486 x 10^-4).
• Isotopes: Atoms with identical atomic numbers but varying mass numbers.

Orbitals and Electron Configuration

• Orbitals (s, p, d, f) describe regions where electrons are likely to be found around the nucleus, characterized by different shapes and sizes.
• Electron Shells: Layers of orbitals around the nucleus, containing different numbers of electrons.

Isomerism in Organic Chemistry

• Organic molecules can have multiple three-dimensional arrangements, resulting in isomers, which can significantly affect their properties.