ORG CHEM | Introduction to Organic Chemistry

Organic Chemistry

study of carbon-containing compounds that for the most part have a carbon-hydrogen bond

Coining of Organic Chemistry

It was first coined in 1806 by Swedish chemist Jöns Jacob Berzelius, who used it to describe compounds derived from living organisms.

Vitalism

Based on the differences between inorganic and organic compounds, this theory arose stating that life force existed only in organic compounds.

Friedrich Wöhler

He synthesized urea, a compound in urine, from the inorganic silver cyanate with ammonium in 1828. It disproved the theory of vitalism, proving that organic compounds can be synthesized in the lab.

The History of Organic Compound Molecular Structure and Isomerism

August Kekulé, Archibald Couper, and Alexander Butlerov proposed the idea that the tetravalency of carbon allows for the creation of chains and rings, explainign the diversse structures or organic compounds.

The History of Covalent Bonding

Gilbert Lewis introduced the concept of covalent bonds in 1916, while Linus Pauling proposed resonance to explain the stability of certain molecules. At the same time, Sir Christopher Ingold introduced reaction mechanisms to better understand the processes involved in organic reactions.

Organic Compounds

• primary composed of C, bonded to H, O, N, S and other non-metals

• covalent bonding (weaker bond)

• low melting and boiling points due to weaker intermolecular forces like van der Waals interactions or hydrogen bonds

• low conductivity

• non-polar (although compounds with polar groups can dissolve in water)

• vast range of structure

• combustible by reacting with oxygen to produce CO2, water, and heat

• have more varied reactions with acids and bases depending on the included functional groups

Inorganic Compounds

• usually do not have carbons, based on metals, salts, and non-metals

• ionic bonding

• higher melting and boiling points (due to stronger intermolecular forces)

• higher conductivity

• polar

• simpler structure

• non-combustible

• have more predictable reactions with acids and bases

Carbon’s Tetravalency

Because carbon has four valence electrons, it can form many kinds of covalent bonds with a variety of elements

Catenation

ability of carbon atoms to form long chains or rings by bonding with other carbon atoms, forming linear, branched, and ring structures

Bond strength and stability

C-C bond and C-H bond are very stable due to bond energies, making carbon-based compounds stable and durable under various conditions.

Isomerism

same molecular formula can have multiple different structures or arrangements of atoms

Stereoisomers

different spatial arrangement

Hybridization

It allows carbons to form different types of bonds by mixing its s and p orbitals into new hybrid orbitals such as sp, sp² , sp³

sp³ Hybridization

Seen in methane (CH₄), carbon is sp³ hybridized, forming four equivalent tetrahedral bonds.

sp² Hybridization

Seen in ethene (C₂H₄), carbon is sp² hybridized, forming a planar structure with a double bond.

sp Hybridization

Seen in ethyne (C₂H₂), carbon is sp hybridized, forming a linear molecule with a triple bond.

Functional Groups

carbons can form various bonds with functional groups

Hydroxyl group

(-OH); found in alcohols

Carbonyl group

(C=O); Found in aldehydes and ketones

Carboxyl Group

(-COOH); Found in carboxylic acids

Amino group

(-NH2); found in amines and amino acids

Pi bonds

bonds formed by the overlap of orbitals in a side-by-side fashion, top bonds in double bonds between carbon atoms

Sigma bonds

bonds formed by the overlap of orbitals in an end-to-end fashion

Bond composition of C=C

one sigma bond and one pi bond

Bond composition of Triple Covalent Bond Between Carbon Atoms

one sigma bond and two pi bonds

Substitution Reactions

One atom or group of atoms is replaced by another (common in alkanes and aromatics).

Addition Reactions

Atoms or groups are added to a double or triple bond (common in alkenes and alkynes).

Elimination Reactions

Atoms or groups are removed, typically leading to the formation of double or triple bonds.

Oxidation-Reduction (Redox) Reactions

Organic compounds can undergo redox reactions where electrons are transferred, particularly involving oxygen or hydrogen atoms.