PHOrgChem (Lecture) | Module 6 (Part 2: ALIPHATIC, AROMATIC HYDROCARBONS AND ALKYL HALIDES ONLY)

Naphtalene

AROMATIC HYDROCARBONS: Simplest polycyclic aromatic hydrocarbon, consisting two fused benzene rings and it is best known for its strong odor

Strong Odor

AROMATIC HYDROCARBONS: Naphtalene is best known for its?

Naphtalene

AROMATIC HYDROCARBONS: This contains 10 delocalized pi electrons, following the Huckel’s Rule

Naphtalene

AROMATIC HYDROCARBONS: Less aromatic than benzene because the delocalization is spread over two ring making it likely reactive

Naphtalene

AROMATIC HYDROCARBONS:

• Melting Point: ~80°C

• Boiling Point: ~218°C

Naphtalene

AROMATIC HYDROCARBONS: Sublimates easily (solid to vapor) due to weak intermolecular forces.

Naphtalene

AROMATIC HYDROCARBONS: Slightly soluble in water but dissolves in organic solvents (benzene, ether). TWO-FUSED BENZENE RINGS

Naphtalene

AROMATIC HYDROCARBONS: Uses and applications → mothballs are insect repellent, they are a precursor to phthalic anhydride which is used in plastics and dyes, they are also used in glue, fuels, and lubricants as a hydrogen donor-solvent and in organic semiconductors

Naphtalene

Anthracene

AROMATIC HYDROCARBONS:

• Melting Point: ~218°C

• Boiling point: ~340°C

Anthracene

AROMATIC HYDROCARBONS: Slightly soluble in water but dissolves well in organic solvents like benzene and chloroform.

Anthracene

AROMATIC HYDROCARBONS: A polycyclic aromatic hydrocarbon with a chemical formula of C14H10

Anthracene

AROMATIC HYDROCARBONS: It consists of three-fused benzene rings in a linear arrangement

Anthracene

AROMATIC HYDROCARBONS: It is aromatic due to its conjugated pi electron system following the huckel’s rule, this delocalization provides stability but makes it less reactive than non-aromatic compounds. THREE-FUSED BENZENE RINGS

Anthracene

AROMATIC HYDROCARBONS: Uses and application → Organic semiconductors, dyes and pigments, scintillators for radiation detection, and precursor to anthraquinone which is used in dyes

Benzo [a] Pyrene

AROMATIC HYDROCARBONS:

• Melting Point: ~179°C

• Boiling Point: ~495°C

Benzo [a] Pyrene

AROMATIC HYDROCARBONS: Insoluble in water but dissolves in organic solvents (benzene, toluene, chloroform). FIVE-FUSED BENZENE RINGS

Benzo [a] Pyrene

AROMATIC HYDROCARBONS: Polycyclic aromatic hydrocarbon with a chemical formula of C20H12

Benzo [a] Pyrene

AROMATIC HYDROCARBONS: It consists of five fused benzene rings making it highly conjugated and aromatic.

Benzo [a] Pyrene

AROMATIC HYDROCARBONS: Like any other polycyclic aromatic hydrocarbon, this follows Hückel’s rule. This extensive pi conjugation makes it thermodynamically stable. However, it may region or the group structure, making areas form high electron density, making some positions chemically reactive.

Benzo [a] Pyrene

AROMATIC HYDROCARBONS: Uses and application → used in research to study cancer mechanisms and as an indicator of polycyclic aromatic hydrocarbon pollution in environmental studies

Benzo [a] Pyrene

AROMATIC HYDROCARBONS:

Coronene

AROMATIC HYDROCARBONS:

• Melting Point: ~438°C

• Boiling Point: Decomposes before boiling

Coronene

AROMATIC HYDROCARBONS: Insoluble in water but dissolves in organic solvents (benzene, toluene). SIX-FUSED BENZENE RINGS

Coronene

AROMATIC HYDROCARBONS: A polycyclic aromatic hydrocarbon with a structure resembling a benzenoid.

Coronene

AROMATIC HYDROCARBONS: It is considered a "super benzene" due to its six fused benzene rings forming a hexagonal shape.

Coronene

AROMATIC HYDROCARBONS: It follows Hückel’s rule and is highly aromatic with strong pi electron delocalization, making it very stable. Its planar and symmetrical structure contributes to strong pi–pi stacking interactions, which affect its solid-state properties.

Coronene

AROMATIC HYDROCARBONS: Uses and applications → organic semiconductors, in graphene related materials used in carbon nanotechnology, used in fluorescent, dyes, and UV-blocking materials, used as polymer additives for heat resistance. These compounds can instate the wide applications of aromatics in science industry

Aspirin (Acetylsalicylic acid)

WHAT DRUG?

AROMATIC RING: Benzene ring (salicylate structure)

• Benzene ring increases stability by delocalizing electron, allowing effective enzyme inhibition, which reducing inflammation and pain.

Paracetamol (Acetaminophen)

WHAT DRUG?

AROMATIC RING: Benzene ring (hydroxy & amide substitutions)

• Benzene ring enhances lipophilicity, allowing it to cross biological membranes easily

• The stable structure prevents rapid degradation it the body

Ibuprofen

WHAT DRUG?

AROMATIC RING: Benzene ring (with carboxyl and isobutyl groups)

• Aromaticity of benzene ring stabilizes non-polar interaction with COX enzyme, enhancing anti inflammatory effects which improve drug metabolism and distribution

Diazepam (Valium)

WHAT DRUG?

AROMATIC RING: Benzodiazepine fused ring system

• The presence of Benzodiazepine fused ring enhances the binding to GABAA receptors, increasing sedative effects, improves lipid solubility, ensuring faster CNS penetration.

Chlorpromazine

WHAT DRUG?

AROMATIC RING: Phenothiazine core (three-ring system)

• The presence of Phenothiazine enhances stability and receptor binding to dopamine D2 receptors and maintains effectiveness for longer duration

Morphine

WHAT DRUG?

AROMATIC RING: Phenanthrene core (three fused benzene rings)

• Phenanthrene core provides a rigid structure for opioid receptor binding, which increase stability and bioavailability in the body

Tamoxifen

WHAT DRUG?

AROMATIC RING: Triphenylethylene structure

• The presence of triphenylethylene structure, an aromatic ring structure interacts with estrogen receptors blocking estrogen driven cancer growth which enhances metabolic stability

Losartan

WHAT DRUG?

AROMATIC RING: Biphenyl system

• Hypertensive drug

• The presence of the biphenyl system improves the receptor activity for angiotensin receptors and enhances bioavailability and drug effectiveness.

Sildenafil (Viagra)

WHAT DRUG?

AROMATIC RING: Pyrazolopyrimidine system ●

• The presence of pyrazolopyrimidine system enhances binding receptors to phosphodiesterase 5, increasing vasodilation, provide stability and longer lasting effects

Fluoxetine (Prozac)

WHAT DRUG?

AROMATIC RING: Trifluoromethyl benzene system

• The presence of the trifluoromethyl benzene system enhances lipophilicity, allowing it to cross the blood-brain barrier and stabilize the drug’s interaction with serotonin transporters.

Stability

HOW DOES AROMATICITY AFFECTS DRUG EFFECTIVENESS: Aromatic delocalization prevents rapid degradation

Lipophocity

HOW DOES AROMATICITY AFFECTS DRUG EFFECTIVENESS: Enhances absorption and Blood Brain Barrier crossing and receptor binding. The electron pi-pi stacking and hydrophobic interactions improves drug target interactions

Alkyl Halides

Organic compounds where a halogen replaces a hydrogen in alkane

Alkyl Halides

Organic compounds where a halogen (F, Cl, Br, I) replaces a hydrogen in an alkane

Alkyl Halides

Higher boiling points than corresponding alkanes.

Insoluble

ALKYL HALIDES: ________ in water but soluble in organic solvents.

Alkyl Halides

Undergo nucleophilic substitution reactions.

Alkyl Halides

Participate in elimination reactions.

Halothane

An inhalation anesthetic containing alkyl halides which contributes to its stability and volatility, making it effective as an inhaled anesthetic.