M3 Introduction
In this module, we will learn about the structural effects of their role to properties (i.e. solubility, boiling
point, melting point, acidity/basicity), and reactivity of organic compounds.
What do you mean by structural effects?
These are the effects on the stability and reactivity of organic molecules through resonance or electron
delocalization consisting of pi, lone pair, and sigma electrons.
The movement of electrons may be from pi to lone pair, pi to sigma bond, lone pair to pi, sigma to lone pair,
sigma to pi bond. These movements of electrons are also influenced by the inductive effects exhibited by
the atoms attached to the molecules which are electron attracting, electron repelling, and steric effects that
lead to the reactivity of the molecules.
Reactivity of molecules is determined due to the formation of reactive sites in the form of positive (+) ions
and negative (–) ions where molecular interactions take place like hydrogen bonding, dipole-dipole
interaction, and London dispersion forces.
Hydrocarbon Derivatives 1 (Oxygen Containing Organic Compound)
A derivative is something that is based on another source. In our case, hydrocarbon derivatives are based
on simple hydrocarbon compounds that contain only hydrogens and carbons. Hydrocarbon derivatives
contain at least one element other than hydrogen or carbon, such as oxygen, nitrogen or one of the halogen
atoms (elements in column 7A.)
Most of the time, the atoms present in a hydrocarbon derivative are attached as part of a distinct group.
These groups are known as functional groups because they affect how the compound contains hydrogen
atoms and carbon.
Alcohol contains one or more hydroxyl (OH) group(s) directly attached to a carbon atom(s), of an aliphatic
system (CH3OH) while a phenol contains –OH group(s) directly attached to a carbon atom(s) of an aromatic
system (C6H5OH).
The substitution of a hydrogen atom in a hydrocarbon by an alkoxy or aryloxy group (R–O/Ar–O) yields
another class of compounds known as ‘ethers’, for example, CH3OCH3 (dimethyl ether). You may also
visualize ethers as compounds formed by substituting the hydrogen atom of the hydroxyl group of an
alcohol or phenol by an alkyl or aryl group.
M3 Lesson 1 Molecular Interactions & Structural Effects
Intermolecular forces are the attractive forces that exist between molecules or particles and influence the
physical properties of the substance. Compared to bonding forces, intermolecular forces are relatively weak
because they involve smaller charges that are farther from each other. Organic molecules typically exhibit
three types of intermolecular forces:
Dipole-dipole attraction
This is a predominant force between polar molecules. Polar molecules exhibit a dipole moment (the centers
of the positive and negative charges do not coincide) and they can attract each other electrostatically by
lining up so that their positive and negative ends are near each other.
Hydrogen bonding
Molecules in which hydrogen is bound to very small highly electronegative atoms such as N, O, or F exhibit
strong dipole-dipole forces. Because these are unusually strong, they are given a special name. Two factors
account for the strength of the attractive forces are: (a) the great polarity of the bond and, (b) the close
approach of the dipole because of the small size of the H atoms.
London dispersion forces (van der Waals)
These are relatively weak forces existing in atoms and nonpolar molecules. Because of the movement of
electrons, atoms can develop a momentary nonsymmetrical distribution that produces a temporary dipole.
This instantaneous dipole can induce a similar dipole in a neighboring atom. This leads to an inter-atomic
attraction that is weak and short-lived.
Large atoms or molecules have a greater number of electrons, thus, are more ‘polarizable’ and have stronger
London dispersion forces. Polarizability refers to the ease with which the electron cloud of a particle can be
distorted.
Structural Effects on Boiling Point, Melting Point, and Solubility
Intermolecular forces are related to certain properties of molecules. The strength of the intermolecular
forces determines whether a compound has a high or low boiling point and melting point and whether a
compound is soluble or insoluble in a given solvent.
Boiling point
The boiling point refers to the temperature at which a liquid is converted to the gas phase. Generally, a
stronger intermolecular force results in lower pressure leading to a higher boiling point.
Among hydrocarbon groups, the boiling point increases with increasing molecular weight. Branching of the
carbon chain lowers the boiling point because of the lesser point of contact. The reverse is true for
cylindrically shaped hydrocarbons or the straight-chain hydrocarbons. Their cylindrical shape allows a
greater point of contact, requiring higher energy (higher temperature) to break these molecules apart,
resulting in the increase of boiling point.
Melting point
The melting point refers to the temperature at which a solid is converted to the liquid phase at 1 atm
pressure. At this temperature, molecular motion due to increased thermal energy is enough to break down
the lattice structures of the crystals. This temperature for a given crystal would remain constant until all of
the solid phase changes to a liquid. Like the boiling point, the melting point increases with increasing
strength of intermolecular forces.
Solubility
Solubility is the amount of solute that dissolves in a given amount of solvent. It is usually reported in grams
of solute per 100 mL of solution (g/100 mL).
The general rule for solubility is ‘like dissolves like’ – indicating substances of similar polarity will dissolve
each other. For example, polar organic compounds are water-soluble, given that water is also polar, only if
they are small in terms of molecular weight and contain nitrogen (N) or oxygen (O) atom that can hydrogen
bond with water. Hydrocarbons and other nonpolar organic compounds are insoluble in water but soluble
in nonpolar solvents.
Stronger intermolecular forces increase solubility in solvents with similar polarities. Branching of the
molecular structure increases solubility because of increased surface area. Moreover, increasing molecular
weight generally decreases solubility.
M3 Lesson 1 Resonance, Inductive Effect & Structural Effects on Acidity/Basicity
Resonance
One useful concept in organic chemistry is resonance. Resonance structures allow us to describe molecules
or ions for which a single Lewis structure is inadequate. A conventional way of representing resonance
structures is done as follows. First, write two or more equivalent Lewis structures (calling them resonance
structures/contributors). Second, connect these structures by double-headed arrows (↔). The real
molecule or ion is a hybrid of all these contributory structures. An example is shown below.
Rules in writing resonance structures
All resonance structures/contributors must obey the octet rule.
Structures differ only in the placement of electrons.
Nuclei can’t be moved and bond angles must remain the same.
The number of paired and unpaired electrons must remain the same for all structures.
Inductive Effect
This property exists because of the electronegativity difference between atoms. Electronegative atoms tend
to disperse the electron cloud towards them, creating a dipole. This unequal distribution of the electron
cloud makes the bond polar, as shown below.
Inductive effect may either be (1) electron attracting, or (2) electron repelling. Electron-attracting inductive
effect includes cases where inductive groups are attracted to the central atom whereas the latter case
involves electron-withdrawing groups which stabilize the central atom.
Structural Effects on Acidity/Basicity
Acid-base chemistry is important in a wide variety of daily applications. Television commercials link pH to
products such as shampoos, deodorants, feminine wash, and antacids. A famous environmental concern
oftentimes mentioned in news articles and magazines is ‘acid rain’. In our bodies, there are complex systems
that carefully control the acidity of our blood (shown in the figure below) since even slight deviations may
lead to serious illness and death.
Although the terms acids and bases seem familiar, have you wondered what makes a substance acidic or
basic? To answer this, we will first go through the acid-base theories. Later, we will dive deeply into their
relationship with structural effects.
THE ACID-BASE THEORIES
Arrhenius Theory
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Arrhenius acid – a substance that contains hydrogen and produces hydronium ions (H 3O+) in
aqueous solutions (Examples: HCl, HNO3, H2SO4)
Note: H+ does not exist in water. Instead, it reacts with water to form the hydronium ion, H 3O+.
H+(aq) + H2O(l) → H3O+(aq)
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•
Arrhenius base – a substance that contains the hydroxyl group (OH) and produces hydroxide ions
in aqueous solutions (Examples: NaOH, KOH, NH3)
The Arrhenius concept only applies to aqueous solutions.
Brønsted-Lowry Theory
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Brønsted-Lowry acid – any hydrogen-containing molecule that is capable of releasing a
proton (proton donor)
Brønsted-Lowry base – any molecule capable of accepting a proton (proton acceptor)
NH3 (aq) + H2O (l) → NH4+(aq) + OH–(aq)
NH3 – Brønsted-Lowry base
OH– – conjugate base
H2O – Brønsted-Lowry acid
NH4+ – conjugate base
Lewis Theory
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Lewis acid – electron-pair acceptor
Lewis base – electron-pair donor
AlCl3 (aq) + Cl– (aq) → AlCl4– (aq)
AlCl3 – Lewis acid
Cl– – Lewis base
Did you know?
The origin of the acid-base concept dates back in 1777 when Antoine Lavoisier tried to explain what makes a
substance acidic. He proposed that oxygen was an essential element in acids. However, in 1808, Humphry
Davy demonstrated that some acids do not contain oxygen. An example is a hydrochloric acid which contains
only hydrogen and chlorine. Finally, in 1884, Svante Arrhenius was the first to explain the essential concept
of acidity and basicity of substances.
The Effect of Structure on Acid-Base Properties
Now that we have already described the nature of acids and bases, let us examine closely which structural
components affect the acidic or basic property of an organic molecule.
ATOMS BONDED TO HYDROGEN ATOM
Across a period, acidity increases because of increasing electronegativity. Down a group, acidity increases
because of decreasing orbital overlap between the atom and proton.
INDUCTIVE EFFECT
In the presence of electronegative atoms, the electrons are dispersed, C–H bonds become weak due to this
dispersion. Thus, protons are easily abstracted.
HYBRIDIZATION
Atoms with higher %s characters are more electronegative which means they tend to hold more tightly their
valence electrons.
RESONANCE EFFECT
This structural effect greatly stabilizes the conjugate base because the negative charge is dispersed to a
larger area.
STERIC EFFECT
The steric effect increases the basic character of a molecule since it allows the lone-pair electrons to be less
tightly held, thus, more available for donation.
M 3 Lesson 2 Alcohols , Phenols & Ethers
Alcohols, Phenols, and Ethers
These three are classes of organic compounds having a wide usage in a broad range of industries as well as
for domestic purposes. But, what are they?
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•
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Alcohol is the product we get when a saturated carbon atom bonds to a hydroxyl (-OH) group.
Phenol is what we get when the -OH group replaces the hydrogen atom in benzene.
Ether is the product that we get when an oxygen atom bonds to two alkyl or aryl groups.
Depending on the number of hydroxyl groups attached, alcohol can be classified into three types.
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Monohydric alcohols: They contain one -OH group. Example, CH3CH2-OH
Dihydric alcohols: They contain two -OH groups. Example, 1,2-Ethanediol.
Trihydric alcohols: They contain three -OH groups. Example 1,2,3-Propantriol.
Classification of Alcohol: Mono-hydric, Di-hydric, Tri-hydric
Depending on the number of carbon atoms which are directly attached to the carbon that is bonded with
the -OH group, alcohols can be classified into three types.
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Primary alcohols: One carbon atom is directly attached.
Secondary alcohols: Two carbon atoms are directly attached.
Tertiary alcohols: Three carbon atoms are directly attached.
Classification of Alcohol: Primary, Secondary and Tertiary Alcohol
1. Reaction with Metal
When ethanol reacts with sodium metal (a base) sodium ethoxide and hydrogen gas are produced.
2ROH + Na→2RO+Na– + H2
2. Formation of Halides
Halogens such as chlorine or bromine replace the -OH group in an alcohol.
ROH+ Zn+HCl → R-Cl
R2C-OH alcohol + HCl→ R2CCl
3. Reaction with HNO3
There is oxidation, accompanied by gas evolution (slow but progressive) in this reaction.
R-OH + HO-NO2→ R-O-NO2
4. Reaction with Carboxylic Acid (Esterification)
The reaction of the carboxylic acid with an alcohol and an acid catalyst leads to the formation of ester (along
with water). This is Fischer esterification.
R-OH +R’-COOH +H+↔ R’-COOR
5. Dehydration of Alcohol
Alcohols dehydrate in an acidic medium. As per the Satyzeff’s Rule, intra-molecular dehydration leads to the
formation of alkene while intermolecular dehydration forms ether.
6. Haloform Reaction
Compound that has the CH3CO- group (or compound on oxidation gives CH3CO – group) which is bonded
with a C or H, in the presence of halogen and mild alkali gives haloform. CH 3-CH2-COCH2-CH3, CH3-CO-Cl,
CH3COOH will not respond to haloform reaction while CH3CH2OH will respond to the haloform reaction.
Phenols are the organic compounds that have a benzene ring bonded to a hydroxyl group. It is also known
by the name of carbolic acids. They are weak acids and generally form phenoxide ions by losing one positive
hydrogen ion (H+) from the hydroxyl group.
In earlier days, people were able to synthesize phenol from coal tar. It was a very complex and lengthy
process. It had a lot of risks associated with it as well. Nowadays, with advancements in technologies,
however, certain new methods have come up for the preparation of phenols in laboratories.
Nomenclature of Phenols
The simplest derivative of benzene is Phenol. It is the common name as well as an accepted IUPAC name.
Both in the common and in the IUPAC system, we name the substituted phenols as the derivatives
of phenols (Links to an external site.).
In the common system, we indicate the substituent position present on the benzene ring with respect to –
OH group by adding the prefix such as ortho (o-) for 1:2, meta (m-) for 1,3 and para (p-) for 1,4.
However, in the IUPAC system, we use Arabic numerals to indicate the position of the substituent w.r.t –OH
group. The carbon (Links to an external site.) carrying the OH group gets the number 1. The phenols having
a carbonyl group such as aldehyde, ketonic, carboxyl or an ester group get their names as hydroxyl
derivatives of the parent aromatic compound.
In laboratories, chemists primarily synthesize and derive phenol from benzene derivatives. In this chapter,
we will look at some of the ways in which we can produce phenols commercially in laboratories.
1) Preparation of Phenols from Haloarenes
Chlorobenzene is an example of haloarenes. We can obtain chlorobenzene by the monosubstitution of a
benzene ring. When chlorobenzene fuses with sodium hydroxide at 623K and 320 atm, we obtain sodium
phenoxide. Finally, sodium phenoxide on acidification gives phenols.
2) Preparation of Phenols from Benzene Sulphonic Acid
It can obtain Benzenesulphonic from benzene by reacting it with oleum. Benzenesulphonic acid, thus
formed, is treated with molten sodium hydroxide at high temperatures. This process leads to the formation
of sodium phenoxide. Finally, sodium phenoxide on acidification gives phenols.
3) Preparation of Phenols from Diazonium Salts
When treated an aromatic primary amine with nitrous (NaNO2 + HCl) acid at 273 – 278 K, it can easily obtain
diazonium salts. These diazonium salts are highly reactive in nature. Upon warming with water, these
diazonium salts finally hydrolyze to phenols. We can also obtain phenols from diazonium salts by treating
them with dilute acids.
4) Preparation of Phenols from Cumene
Cumene is an organic compound that we can obtain by the Friedel-Crafts alkylation of benzene with
propylene. Upon oxidation of cumene (isopropylbenzene) in presence of air, we obtain cumene
hydroperoxide.
Upon further treatment of cumene hydroperoxide with dilute acid, we get the phenols. We also produce
acetone as one of the by-products of this reaction in large quantities. Hence, phenols prepared by these
methods need purifications.
Phenols and Their Physical Properties
Phenols are the organic compounds that have a benzene ring bonded to a hydroxyl group. We also name
them as carbolic acids. They exhibit unique physical and chemical properties that are mainly due to the
presence of a hydroxyl group. Let us discuss some of the important physical properties of phenols in the
section below.
1) The Boiling Point of Phenols
Phenols generally have higher boiling points in comparison to other hydrocarbons with equal molecular
masses. The main reason behind this is the presence of intermolecular hydrogen bonding between hydroxyl
groups of phenol molecules. In general, the boiling point of phenols increases with an increase in the number
of carbon atoms.
2) The Solubility of Phenols
The hydroxyl group determines the solubility of phenol in water. The hydroxyl group in phenol is responsible
for the formation of intermolecular hydrogen bonding. Thus, hydrogen bonds form between water and
phenol molecules which make phenol soluble in water.
3) The Acidity of Phenols
Phenols react with active metals such as sodium, potassium, etc. and give the corresponding phenoxide.
These reactions of phenols indicate its acidic nature. In phenol, the sp 2 hybridized carbon of the benzene
ring attached directly to the hydroxyl group acts as an electron-withdrawing group.
Thus, it decreases the electron density of oxygen. Due to the delocalization of negative charge in the
benzene ring, phenoxide ions are more stable than alkoxide ions. Therefore, we can say phenols are more
acidic than alcohols.
In this chemical compound, a hydroxyl group directly attaches to an aromatic hydrocarbon. Cumene,
diazonium salts, etc. form phenols.
Reactions of Phenol
a. Formation of Ester
Phenyl esters (RCOOAr) do not form directly from RCOOH, but for this acid chlorides or anhydrides react
with ArOH in the presence of a strong base.
(CH3CO)2O
Phenylacetate
+
C6H5OH
+
NaOH
C6H5COCl
Phenyl benzoate
+
C6H5OH
+
NaOH
→
→
CH3COOC6H5 +
C6H5COOC6H5 +
CH3COONa
Na+Cl–
b. Hydrogenation
Hydrogenation of phenol forms cyclohexanone.
c. Oxidation of Quinones
Phenols get easily oxidized to para-benzoquinone. This when reduced forms quinones.
+
+
H2O
H2O
d. Electrophilic Substitution
The —OH and even the —O(phenoxide) are strongly activating ortho, para – directing. Electrophilic
monosubstitution in phenols happens in special mild conditions because they are highly reactive and favors
both polysubstitution and oxidation.
e. Halogenation
There is a formation of monobromophenol, on treating phenols with bromine in the presence of a solvent
of low polarity like CHCl3 at low temperature.
M3 Lesson 2 Alcohols, Phenols, & Ethers
Ethers are a class of organic compounds that have an oxygen atom attached to two same or different alkyl
or aryl groups. We can write down the general formula for ethers as R-O-R,
R- O-Ar or Ar-O-Ar.
Classification of Ether
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Symmetrical ether: It has two identical groups attached to the oxygen atom.
Asymmetrical ether: It has two different groups attached to the oxygen
Physical Properties of Ethers
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An ether molecule has a net dipole moment. We can attribute this to the polarity of C-O bonds.
The boiling point of ethers is comparable to the alkanes. However, it is much lower compared to
that of alcohols of comparable molecular mass. This is despite the fact of the polarity of the C-O
bond.
The miscibility of ethers with water resembles those of alcohols.
Ether molecules are miscible in water. We can attribute this to the fact that like alcohols, the
oxygen atom of ether can also form hydrogen bonds with a water molecule.
Nomenclature of Ethers
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Common System: We get the common names of ethers by naming the two alkyl or aryl groups
linked to the oxygen atom as separate words in alphabetical order and adding the word ether. In
the case of symmetrical ethers, we use the prefix di before the name of the alkyl or the aryl group.
IUPAC system: In the IUPAC system, ethers are Alkoxy alkanes. The ethereal oxygen is taken with
the smaller alkyl group and forms a part of the alkoxy group. On the other hand, the larger alkyl
group is taken to be part of the alkane.
Ether is an organic compound that has an oxygen atom, connected to two alkyl and aryl groups, known as
the ether group.
Reactions of Ether
Ethers are relatively unreactive compounds. The ether linkage is quite stable towards bases, oxidizing
agents, and reducing agents. Therefore, we must remember that with respect to the ether linkage, ethers
undergo just one kind of reaction. It is cleavage by acids :
R-O-R’ + HX → R-X + R’-OH R’ ¾X
Reactivity of HX : HI > HBr > HCl
Cleavage takes place only under quite extreme conditions, like in concentrated acids (usually HI or HBr) and
high temperatures. A dialkyl ether produces, initially, an alkyl halide and alcohol. This alcohol may react
further and form a second mole of alkyl halide. For example :
The oxygen of ether is basic, similar to the oxygen of alcohol. The initial reaction between ether and an acid
is no doubt, the formation of the protonated ether. Cleavage, then, involves the nucleophilic attack by a
halide ion on this protonated ether, with the displacement of the weakly basic alcohol molecule.
Such a reaction usually occurs much more readily as compared to the displacement of the strongly basic
alkoxide ion from the neutral ether.
Reactions of Ether Due to an Alkyl Group
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Combustion: Ethers are highly inflammable and they form extremely explosive mixtures with air
giving CO2 and water.
C2H5O C2H5 + 6O2 → 4CO2 + 5H2O
•
Halogenation: The alkyl group undergoes substitution reaction with chlorine or bromine. The
resultant product is halogenated ether in absence of sunlight. However, in presence of sunlight,
it substitutes all the hydrogen atoms of ethers.
CH3CH2OCH2CH3
CH3CHCIOCHCICH3 (α α’-dichloro diethyl ether)
CH3CH2OCH2CH3
C2CI2OC2CI5 (Perchloro diethyl ether)
Reaction of Ether Due to Ethereal Oxygen
Ethers behave as Lewis bases because of the presence of two lone pairs of electrons on the oxygen atom.
Therefore, they form salts with strong acids. The oxonium salts are soluble in acid solution. We can facilitate
the regeneration of ether by hydrolysis of these salts.
Ethers also form coordination complexes with Lewis acids like BF3, AICI3, RMgX etc. Therefore, we can derive
the fact that ethers are very good solvents for Grignard reagents.
Formation of Peroxides
Ethers form peroxide linkage with oxygen when we expose them to air or ozonized oxygen in presence of
sunlight or ultraviolet light. These peroxides are highly poisonous in nature. They are oily liquids and
decompose violently even at low concentrations. Therefore, we must ensure never to evaporate esters to
dryness. It might lead to explosive reactions.
Besides this, we must also check the purity of ether before its use as an anaesthetic agent. An impure ether
(having peroxide linkage) gives red colour when shaken with ferrous ammonium sulphate and potassium
thiocyanate. This could prove to be lethal for the patients on whom we try anaesthesia.
On
mixing
with
KI
solution,
it
liberates
I2 which
turns
starch
paper
blue.
Ethers may be free from peroxide linkages by distilling them with highly concentrated sulphuric acid, H2SO4.
Also, we can check for the peroxide formation by adding a little amount of Cu2O to the ether.
Reactions of Ether Involving Cleavage of Carbon-Oxygen Bond
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Action of dil. H2SO4 : Ethers, on heating with dilute H2SO4 , under high pressure, hydrolyse to
corresponding alcohols.
Action of Conc. H2SO4 : Ethers, on warming with conc. H2SO4 , give alkyl hydrogen sulphate.
R-OR + conc. H2SO4 → 2R HSO4
R-OR’ + conc. H2SO4 → RHSO4 + R’HSO4
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Action of HI:
The products that we get during the action of HI on ethers depend mainly upon the temperature in which
we carry out the reaction.
R-OR + HI
R-OH + RI
R-OR’ + HI
R’-OH + RI
Note: In case of a mixed ether, halogen atom attaches itself to the simpler alkyl group.
CH3OC2H5 + HI → CH3I + C2H5OH
R-R + HI
2RI + H2O
We would observe similar reactions with HCI, HBr & the reactivity order is HI > HBr > HCI.
•
Action of PCI5 : In the presence of heat, we get the following reaction:
R-O-R + PCI5
2RCI + POCI3
•
Action of Acetyl chloride or Acetic anhydride :
•
Dehydration of Ethers:
C2H5OC2H5
•
2CH2=CH2 + H2O
Action of Carbon Monoxide:
C2H5OC2H5, + CO
C2H5COOC2H5
ROR + CO → RCOOR
*ADDITIONAL INFO* (PPT)
ALCOHOLS
Alcohols are compounds containing the hydroxyl (-OH) functional group bonded to an alkyl, R and
thus may be represented by the general formula: ROH
Characteristics:
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Physical state: alcohols are colorless liquids at ordinary room temperatures:
Odor: lower members of the alcoholic group have a characteristic fruity smell.
Density: alcohols are lighter than water.
Solubility: alcohols are completely soluble in water, methanol and ethanol are completely
miscible in water.
• Acidic nature: alcohols are neutral liquids and have no effect on litmus or acid tests.
•
Conductivity: alcohols are non-conductors of electricity.
• Evaporation: evaporates rapidly. To evaporate, alcohol requires heat.
• Flammable or Not Flammable: alcohols are flammable. Should not be used in a room where
oxygen is in use.
Uses:
1. Methyl Alcohol:
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Methanol
CH3OH
Monohydric alcohols
Also known as wood alcohol
Can be prepared from distillation of wood
It is also prepared commercially from carbon monoxide.
Reminder: methyl alcohol should never be applied directly to the body, neither should the
vapors be inhaled. Ingestion of as little as 15mL can cause blindness, 30mL can cause death.
2. Ethyl Alcohol:
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Ethanol
CH₂CH₂OH
Monohydric alcohols
Also known as grain alcohol
In hospital the world alcohol means ethyl alcohol.
Widely used as antiseptic
Used for sponge baths (to reduce fever of a patient)
Used as a beverage, hence, this is not a stimulant; it actually depresses the nervous system
and can remove an individual's normal inhibitions.
• Can be prepared from the fermentation of blackstrap molasses, the residue that result from
the purification of cane sugar.
• Reminder: excessive use of alcohol may cause the destruction of the liver, a condition known
as cirrhosis.
3. Isopropyl Alcohol:
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Monohydric alcohols
should not be taken internally because it is toxic
Used as rubbing alphol
Also used as an astringent
IUPAC NAME: 2-propanol, indicating that the -- OH functional group is on the second carbon
of a three-carbon chain.
4. Ethylene Glycol:
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Dihydric alcohols
Should not be taken internally because it is toxic.
Used in preparations to moisten skin
Also used as a permanent antifreeze in car radiators
IUPAC NAME: 1, -2ethanediol, indicating that an --OH functional group on each carbon atom
of the two-carbon chain.
5. Glycerol:
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Trihydric or trihydroxy alcohol
Used to manufacture soaps
Used in preparation of cosmetics and hand lotions • Used also in suppositories
When added with nitric acid - nitroglycerin (an explosive)
Medical use: when added with nitric acid - nitroglycerin (used to treat angina or heart pain)
6. Other Alcohols:
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Example: menthol
Cyclic alcohol
Has a cooling, refreshing feeling when rubbed on the skin.
Frequently used ingredient in cosmetics and shaving lotions.
Used in cough drops and nasal sprays.
TYPES:
1. Primary Alcohols (1) alcohol is one that contains an --OH functional group attached to carbon that has one
or no carbon atoms attached to it.
2. Secondary Alcohols (2) alcohol is one in which the --OH is attached to a carbon atom having two other
carbon atoms attached to it.
3. Tertiary Alcohols (3) alcohol is one in which the --OH is attached to a carbon atom that has three carbon
atoms attached to it.
Effects of Different Alcohol Concentration in Blood
BLOOD ALCOHOL LEVEL
EFFECT
0.05
Tranquility
0.05 – 0.15
Lack motor coordination
0.15 – 0.20
Intoxication
0.30 – 0.40
Unconsciousness
0.50 or more
May cause death
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An alcohol level of .10% is the legal age limit of intoxication
Higher percentage of alcohol in the blood effects one motor coordination and vision
Alcohol content in Various Beverages
Beverages
Present Alcohol
Pool
Beer
4-6
8 - 12
Urine
7 - 12
14 - 30
Champagne
8 - 10
16 - 28
Distilled Spirit
40 - 95
80 - 190
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Glycerol – used to the preparation of toothpaste.
Phenols
•
compound in which one or more H-atoms in an aromatic nucleus have been replaced by OH group.
Preparation:
1. Replacement of H¹
2. Replacement of the OH group
3. Substitution on the nucleus
4. Condensation
Physical Properties
1. Colorless, crystalline solid
2. Slightly soluble in H2O 3. Antiseptic odor
4. Melting pt. 42-43C
5. Boiling pt. 181-40C
6. High toxic to skin
7. It is very corrosive and poisonous
Chemical Properties
1. Phenol is a weak acid dissociating slightly in aqueous solution.
2. Phenols forms esters but only by direct action an acid.
3. Phenol is reduced when treated strongly with zinc.
4. Phenol gives characteristic blue or purple when combined with aqueous chloride.
Medical Application:
1. Ability to act in antiseptic - toxic to bacteria, burns tissue.
2. used to clean surgical and medical instrument.
3. 4-N hexyl resorcinol much stronger anti bacterial action. Used in throat lozenges and mouth wash.
4. O-phenyl phenol and methyl salicylate
5. Phenols are found in a variety of commercial product including soap, deodorant, ointment, muscle
rub, and spray gargle.
Acid Derivatives:
are compound which are obtained by substitution in the carboxyl group of an acid.
Esters
• Esters: are organic salts that are produced by the reaction of alcohols and acid called esterification.
(carboxylic acid and alcohols).
• Esters: is a chemical compound derived from an acid in which atleast one -OH (hydroxyl) group is
replaced by an -O alkyl (alkoxy)) group.
usually, esters are derived from substitution reaction of a carboxylic acid and an alcohol.
2 Classes of Esters:
I. Inorganic esters - derived from organic acid.
a) alkyl halides
b) alkyl sulfates
c) alkyl phosphates
d) alkyl nitrite
II. Organic esters - derived from RCOOR
a) R- from acid
b) R'- from alcohols