1 Starter activity What’s the most pleasant smell you can think of? And the most revolting?

2 Making and testing perfumes… Chanel No.5 AdvertChanel No.5 Advertisement

3 Scent facts Dogs can detect the difference in smell between non-identical twins AND between identical twins despite the fact they are given the same foods or live in the same environment. (Search Dogs)(Search Dogs) Since Moths lack a nose, they use their antenna for smell. Some male moths can detect a single molecule of a female moth’s sex hormone up to 7 miles (11 km) away. A dozen molecules drives the male crazy!

4 Perfume facts One of the key scents in many male aftershaves is musk, which was originally extracted from glands (called a musk pod) that produce pheromones on the male musk deer. Synthetic forms used now. In May 1921, when the perfume creator Ernest Beaux presented her with a choice of fragrances, Gabrielle Chanel barely hesitated before choosing the fifth one, which was to become CHANEL N°5.CHANEL N°5.

What Chemicals are in Perfumes? Aliphatic & Aromatic Esters Aldehydes & Ketones Alcohols Terpenes Phenols Nitriles Lactones Heterocyclics Acids Sulphur compounds

Esters 34% Alcohols 23% Aldehydes 15% Ketones 10% Musks 6% Hydrocarbons 4% Other 8% Commercial Fragrances

7 Properties of Perfume: Why does a perfume need these properties? Volatile –Low Molecular Weight –Evaporates easily Non-toxic –Will not poison the wearer Does not dissolve in water –Prevents sweating it off Does not irritate the skin

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10 Diffusion animation 1

11 Diffusion Diffusion is when something travels from an area of high concentration to an area of low concentration. For example, consider the scent from a hamburger… The “scent particles” from this hamburger are in high concentration here: Eventually they will “diffuse” out into this area of low concentration:

12 How do our Olfactory sensors work? GAS particles DIFFUSE up our NOSE Inside the Nose: A patch of tiny Neurons the size of a postage stamp with cilia Molecules bind to the cilia Artificial Nose Video Trigger receptors that signal the brain to perceive a smell Differently shaped nerve cells recognize different smells because each smell molecule fits into a nerve cell like a lock and key Each receptor is encoded with a specific gene - if mutated, certain smells are not recognized Periodic Table of SmellElements

13 Keywords synthetic This is when liquid particles have enough energy to turn into gas particles pungent This means something will not dissolve diffusion A type of chemical made when an alcohol is mixed with an acid ester A perfume that is made using man made chemicals insoluble A very strong (and unpleasant) smell evaporate This is the movement of particles from an area of high concentration to an area of low concentration

14 Keywords synthetic A perfume that is made using man made chemicals pungent A very strong (and unpleasant) smell diffusion This is the movement of particles from an area of high concentration to an area of low concentration ester A type of chemical made when an alcohol is mixed with an acid insoluble This means something will not dissolve evaporate This is when liquid particles have enough energy to turn into gas particles

Esters AROMATICS Found in Fats and Oils O  CH 3 —C—O—CH 3 ester group

What are they? How are they made? Formed when an alcohol reacts with a carboxylic acid. Very slow reaction, unless! an acid catalyst used (usually sulfuric acid) A condensation reaction The condensation reaction between the hydroxyl group and the carboxylic acid known as esterification. Reverse reaction = ester hydrolysis

This is why it is a condensation reaction because water is produced! R R’C H2OH2O + OH HO O C RO O + ⇋ Definition of a condensation reaction = two molecules reacting to form a larger molecule with the elimination of a small molecule such as water

Naming Named after alcohol & carboxylic acid from which they are derived. Names of esters end in –oate. CH 3 C CH 2 O O CH 3 ethylethanoate this part from the acid and is named after it this part comes from the alcohol & is named after it - “ol” becomes “yl” let’s name some esters!

NAMING ESTERS

NAME THE FOLLOWING ESTERS. 1.Methanol and Methanoic Acid 2.Ethanol and Ethanoic Acid 3.Butan-1-ol and Methanoic Acid 4.Ethanol and Hexanoic Acid Answers:

Structural formula Although the previous structural formula are the clearest way of showing esters, they can draw out in a shortened form. ethylethanoate CH 3 C CH 2 O O CH 3 Either… Or… CH 3 C CH 2 O O CH 3 In this version the acid part has been written first Identify the group attached to the C=O – this is from the acid The group attached to the –O- is from the alcohol.

Wait! What’s that smell? Esters have strong, sweet smells. Their bouquet is often floral or fruity. This means they are used in food flavorings & perfumes. Also, very good at dissolving organic compounds so often used as solvents. esterfragrance ethyl methanoateraspberries 3-methylbutyl ethanoatepears ethyl 2-methylbutanoateapples phenylmethyl ethanoatejasmine

Esters from phenols -OH group in phenol less reactive to esterification, requires a more vigorous reagent. Use of ethanoic acid in esterification is also known as ethanoylation. Ethanoic anhydride is a more vigorous ethanoylating agent OH

Esters from phenols Ethanoic anhydride used as it is reactive but not too dangerous. Ethanoyl chloride is much more reactive, but, also toxic and hazardous to use. Ethanoic anhydride & ethanoyl chloride are described as acylating agents using an acylating agent is the only way to esterify a phenol alcohols can be esterified using acylating agents or by reacting with a carboxylic acid.

CH 3 CH CH 2 O O CH 3 CH 2 C CH 3 O O CH CH 3 O O ethylmethanoate methylpropanoate methylmethanoate

R R’C H2OH2O + OH HO O C RO O + ⇌ FORWARD REACTION = condensation reaction, the esterification of an alcohol using acid catalyst under reflux. REVERSE REACTION = ester hydrolysis, same catalyst works for both forward & reverse reactions.

+ OH OH - → CH 3 C CH 2 O O CH 3 ethylethanoate + CH 2 CH 3 C -O-O O ethanol ethanoate ion not a reaction that exists in equilibrium (unlike using acid catalyst)

Essential Oils contain Esters

What are Essential Oils? Essential oils are the concentrated extracts of volatile, non-water-soluble aroma compounds from PLANTS. Essential oils are widely used in PERFUMES, cosmetic products, cleaning products and as flavorings in FOODS.

ESSENTIAL OILS Essential oils are mixtures of organic compounds. Contain Carbon. TERPENES are the key components in most essential oils.

The history of essential oils The benefits of essential oils have been recognized for thousands of years. Their use is described in the New Testament of the Bible. They were used in anointing rituals and in HEALING THE SICK.

The history of essential oils The ancient Egyptians used essential oils for EMBALMING RELIGIOUS RITES and MEDICINAL purposes. KING TUT’S tomb was found to contain 50 jars of essential oil when it was opened in 1922.

Modern uses Essential oils CosmeticsFlavours Perfumes Medical Cleaning Insect repellents Dentistry Adhesives

What are essential oils? ‘Essential’ refers to the fact that the oil carries the distinctive essence (SCENT) of the plant. Concentrated, volatile, non-water soluble aroma compounds extracted from plants. Contain NO ARTIFICIAL SUBSTANCES, unlike perfumes and fragrance oils.

Essential oils – Chemistry The distinctive character of an essential oil can be attributed to the functional group present in its key molecule. Esters, aldehydes, ketones and alcohols are all found in essential oils.

Essential oils containing a significant percentage of esters are antispasmodic. Oils high in esters have a pronounced sedative effect. Oils high in esters can often be emotionally uplifting. Some are analgesic Jasmine, Lavender, Medicinal Purposes of Essential Oils

Medicinal Purposes Adaptogenic helps the body adjust to and deal with stress Anti-inflammatory, and effective on skin rashes and skin irritations. Some are good digestive aids Chamomile

MASSAGE THERAPY USING ESSENTIAL OILS

ESSENTIAL OILS: PRESCRIPTION ALTERNATIVES

Essential oils – Perfume The ester linalyl acetate is found in the essential oil lavender. This ester is often added to perfumes.

Essential oils – Cosmetics The essential oil Geraniol is added to some cosmetics to balance and revitalize the skin.

Essential oils – Cleaning The essential oil known as lemon oil contains the terpene d-limonene. It is known for its ability to act as a natural solvent and a cleanser.

Hospital Cleaners Certain essential oils kill bacteria and fungi including MRSA -Staph and E. coli within 2 minutes of contact. Essential oils are blended into soaps and shampoos used in hospitals to eradicate deadly ‘super bugs’.

Essential oil – Cold Sores Melissa oil contains the terpene citral, which is used to combat cold sores.

Essential oils – Toothpaste & Foot Fungus Treatment The essential oil Thymol has antiseptic properties.

Steam distillation Steam distillation is one of the methods used to extract essential oils from plants. Steam passes over the plant and extracts the essential oil. The mixture evaporates and passes into the condenser. The essential oil vapor is chilled and collected.

Steam distillation

Essential Oils Safety Should Always be Considered