Chapter 10 Structure and nomenclature of organic compounds Flashcards
Achiral
Not chiral
Alkyl group
A group obtained by removing a hydrogen atom from an alkane, with a general formula CnH2n+1. For example, methyl is -CH3. Alkyl groups make up branches in organic compounds.
Chin isomers
An isomer of an organic molecule cause by branching of the hydrocarbon chain
Chiral
A chiral object is non-superimposable on its mirror image. A chiral molecule has two optical isomers called enantiomers. Chiral molecules do not have a plane of symmetry
Chiral centre
A carbon atom which is attached to four different groups in a tetrahedral arrangement.
Cis isomers
An isomer in which the highest priority groups attached to the carbons of a double bond are on the same side of the double bond plane
Cis-trans isomers
Isomers that occur when two different groups are attached to each carbon in a carbon-carbon double bond. They occur because there is restricted rotation around the carbon-carbon double bond
Enantiomers
One of a pair of molecules which are mirror images of each other but which cannot be superimposed. Enantiomers are optical isomers
Functional group
An atom or group of atoms in an organic molecule which largely determines the molecule’s properties and reactions
Geometric isomers
A type of stereoisomer which can arise when there is restricted rotation in a molecule such as occurs around a carbon-to-carbon double bond or in a ring structure.
Homologous series
A series of organic compounds in which each member of the group differs from the previous member by -CH2. Examples are alkanes, alkenes and alcohols
Hydrocarbon
A compound which contains only hydrogen and carbon atoms. Examples are alkanes and alkenes
Isomers
Molecules which have the same molecular formula but which have different arrangements of atoms in 3-D space.
Molecular formula
A formula which gives the type and number of atoms in a molecule.
Optical isomers
A type of stereoisomer which can arise when there is restricted rotation in a molecule such as occurs around a carbon-to-carbon double bond or in a ring structure.
Organic molecule
A molecule based on a hydrocarbon skeleton. Organic molecules also commonly contain other non-metal elements, such as oxygen, nitrogen, sulphur and chlorine.
Postitional isomers
Isomers which arise because of different positions of the functional groups on the carbon chain
Primary alcohol
An alcohol in which the carbon that is bonded to the -OH group is attached to only one alkyl group
Saturated
Describes hydrocarbons or organic molecules with only single carbon-to-carbon bonds
Secondary alcohol
An alcohol in which the carbon that is bonded to the -OH group is also attached to two alkyl groups. The alkyl groups may be the same or different
Semi-structural formula
A formula which summarises the structure of a molecule in a single line of text
Skeletal formula
A formula which represents the structural arrangement of atoms in a molecule where covalent bonds are represented as lines and where the symbols for carbon and hydrogen are omitted and where C-H bonds are not shown.
Stereoisomers
Comprise optical isomers and geometric isomers. Stereoisomers are isomers where all the atoms are connected in the same order, but which still have different arrangements in 3-D space.
Structural formula
A formula which represents the three-dimensional arrangement of atoms in a molecule
