Functional Groups
• A functional group is an atom or a group of atoms with characteristic chemical and physical properties.
• Most organic molecules contain a carbon backbone consisting of C-C and C-H bonds to which functional groups are attached.
• Structural features of a functional group include:
• Heteroatoms—atoms other than carbon or hydrogen. • π Bonds most commonly occur in C-C and C-O double bonds.
2
Functional Groups
• Functional groups distinguish one organic molecule from another. • They determine a molecule’s:
• geometry
• physical properties
• reactivity
3
Reactivity of Functional Groups
• Heteroatoms and π bonds confer reactivity on a particular molecule. • Heteroatoms have lone pairs and create electrondeficient sites on carbon.
• A π bond makes a molecule a base and a nucleophile, and is easily broken in chemical reactions.
4
Hydrocarbons
• Hydrocarbons are compounds made up of only the elements carbon and hydrogen.
• They may be aliphatic (ex. alkanes, alkenes, alkynes) or aromatic.
5
Aliphatic Hydrocarbons
• Aliphatic hydrocarbons have three subgroups.
• Alkanes have only C—C σ bonds and no functional group. • Alkenes have a C—C double bond.
• Alkynes have a C—C triple bond.
6
Aromatic Hydrocarbons
• Aromatic hydrocarbons are so named because many of the earliest known aromatic compounds had strong, characteristic odors.
• The simplest aromatic hydrocarbon is benzene.
• The six-membered ring and three π bonds of benzene comprise a single functional group, found in most aromatic compounds.
7
Functional Groups with CarbonHeteroatom (C-Z) σ bonds
• Several types of functional groups contain C-Z σ bonds. • The electronegative heteroatom Z creates a polar bond, making carbon electron deficient.
8
Functional Groups with C-Z σ bonds
9
Functional Groups with C=O Group
• This group is called a “carbonyl group”.
• The polar C-O bond makes the carbonyl carbon an electrophile, while the lone pairs on O allow it to react as a nucleophile and base.
• The carbonyl group also contains a π bond that is more easily broken than a C-O σ bond.
10
11
Importance of Functional Groups
A functional group determines all of the following properties of a molecule:
• bonding and shape
•
type and strength of intermolecular forces • physical properties
• nomenclature
• chemical reactivity
12
Molecules can Contain Several
Functional Groups
• Each of these molecules have several different functional groups
• These molecules would also have several different types of reactivity
13
Question
• Identify the functional groups in the molecules shown.
14
Intermolecular Forces
• Intermolecular forces are interactions that exist between molecules. • Functional groups determine the type and strength of these interactions.
• Ionic and covalent compounds have very different intermolecular interactions.
15
Ion-Ion Interactions
• Ionic compounds contain oppositely charged particles held together by extremely strong electrostatic interactions. • These ionic interactions are much stronger than the intermolecular forces present between covalent molecules. 16
Intermolecular Forces in Covalent Molecules
• Covalent compounds are composed of discrete molecules. • The nature of the forces between molecules depends on the functional group(s) present.
• There are three different types of interactions, shown below in order of increasing strength:
§ van der Waals forces
§ dipole-dipole interactions
§ hydrogen bonding
17
van der Waals Forces
• van der Waals forces are also known as London forces.
• They are very weak interactions caused by momentary changes in electron density in a molecule.
• They
Related Documents: Carbon and Intermolecular Forces Essay
Carbon Chemistry Introduction to Carbon Chemistry: Intermolecular Forces * Intermolecular forces increase as the states go from gas → liquid → solid. Thus, increasing/decreasing temperature can change the forces and increasing the pressure increases the forces. * Intermolecular forces are the attractive forces between molecules, ion and ions and molecules. * Without intermolecular forces all substances would be gases. * Intermolecular forces are weaker than intramolecular forces…
functional group will impact the molecular structure of the alcohol, making it either primary (1° ), secondary (2° ), or tertiary (3° ). If the OH is bonded to only one other carbon, it is a primary alcohol (eg. 1-butanol); if bonded to two other carbons, it is a secondary alcohol (eg. 2-butanol); if bonded to three other carbons, it is a tertiary alcohol (eg. 2-methyl-2-propanol). Due to the placement of the hydroxyl functional group in each of the degrees of alcohol, the reactivity of each should…
Identify data sources, gather, process and analyse information from secondary sources to identify the industrial separation processes used on a mixture obtained from the biosphere, lithosphere, hydrosphere or atmosphere and use the evidence available to: Identify the properties of the mixture used in its separation Identify the products of separation and their uses Discuss issues associated with wastes from processes used |Sphere…
an ion, so many would say that the fact that it is polar is trivial. I'm not trying to make a judgment here, though I'm inclined to agree. Methane forms a perfect tetrahedron with sp3 hybridization with four hydrogen atoms around the central carbon and showing bond angles of 109.5 degrees. A water molecule also shows sp3 hybridization, but two of the pairs of electrons around the central oxygen are bonded to hydrogen’s and two are lone pairs. The lone pairs are often described as taking up more…
In general the boiling point of a molecule increases as the length of the carbon chain increases, this is due to the fact that there are now more atoms within the molecule and therefore more intermolecular forces to be overcome (Unknown: 2014). Intermolecular forces are forces that act between atoms in a molecule or molecules themselves (Hydrocarbon boiling points: 2014). The more carbon atoms the heavier the entire molecule becomes, this means that more energy is required to make the phase change…
all the atoms or molecules together in a giant molecule, e.g. diamond (C), quartz (SiO2), silicon (Si), silicon carbide (SiC) Covalent bonds between atoms within each molecule, weak intermolecular forces between molecules, e.g sulphur (S8), H2O, halogens (F2, Cl2, Br2, I2) Intermolecular Forces (weak) instantaneous dipole – induced dipole attractions van der Waal’s monoatomic Nobel gases (He, Ne, Ar, Xe, Kr) simple molecular covalent Elements, e.g. halogens, sulphur (S8)…
Saturated fats consist of carbon chains with only single carbon-carbon bonds, with the maximum number of hydrogen, therefore making them saturated. * They have an overall straight shape. The structure of saturated fats allows for many hydrocarbon chains to be tightly packed together. * Saturated fats can be found naturally from animal sources such as lard. * However this fat can be linked to heart disease. * Unsaturated fats consist of at least one double carbon-carbon bond in a cis isomer…
difference in charge between the positive ions and the sea of delocalised electrons holds the metal together. Sodium is a relatively weak metal, as there is only one electron per ion, so the difference in charge is less, and therefore the force of attraction. However in a metal like iron the difference in charge will be much greater as there are more electrons in the outer shell. Giant Metallic Structures ● Strong, high BP, high MP ● Metals are elastic and will return to their original shape…
water and carbon dioxide into glucose and oxygen. All green plants go through the process of photosynthesis as it is their source of life of all organisms. Without this process, no organism on earth will be able to harness and utilize the sun’s energy, leading to everything perishing. Photosynthesis is an endothermic reaction because it absorbs energy emitted by the sun. Light energy is converted to chemical energy (glucose). This process occurs only in green plants Light Carbon Dioxide…