Mod 7.1 - Nonmenclature Flashcards
What is an alkane?
These are hydrocarbons which have only single bonds
What is the general equation for alkanes?
C(n) H (2n+2)
How to name alkanes with chain branching?
- Find the longest chain - this is called the parent chain
- Determine Carbon 1, this is a carbon atom at one end of the parent chain that has a side group, or halogen closest to it that would be named first aplhabetically
- The parent chain must have the lowest numbers used in naming its side groups overall
- If there are two or more different side chains or halogens, they are listed in alphabetical order, ignoring the prefixes
- If there are two or more of the same side-chains, their poosition numbers are listed multiplke times and the prefix (di-, tri-, tetra, penta- etc are applied) and separated by commas
- The parent name is named last. Do not write a dash before it
I.e. 1,1,2,3,4-pentamethylpentane
How do you name cycloalkanes with chain branching?
- Count the number of carbons in the ring
- Determine Carbon 1, this is a carbon atom at one end of the parent chain that has a side group, or halogen closest to it that would be named first alphabetically
- The parent ring must have the lowest numbers used in naming its side groups overall
- If there are two or more different side chains or halogens, they are listed in alphabetical order
- If there are two or more of the same side chains, their position numbers are listed multiple times and the prefix (di-, tri- etc are applied) and separated by commas
- The parent name is named last. Do not write a dash before it. Do not forget to write the prefix ‘cyclo’ such as ‘cyclohexane’
What are alkenes?
They are a family of hydrocarbons that has a double bond between two carbon atoms
What is the general formula for alkenes?
C(n) H(2n)
How do you name alkenes?
- Find the longest chain
- Determine Carbon 1
- The numbers of the side groups will not matter as the priority is having the double bond as having the lowest numbers
- If there are two or mmore different side chains, they are listed in alphabetical order
- If there are two or more of the same side chains their position numbers are listed multiple times and the prefix (di, tri, tetra etc are applied)
Note: if the alkene is in a ring, then the prefix cycli is applied before the base name. For cycloalkenes, Carbon 1 is always at the start of the double bond
I.e. 2,4,4-trimethylhex-2-ene
What is an alkyne?
Alkynes are hydrocarbons that contain a triple bond between two carbon atoms
What is the general formula for an alkyne?
C(n) H(2n-2)
How do you name alkynes?
- Number the longest chain from the end that gives the alkyne functional group the lowest locant number possible.
- The preferred IUPAC method (2005) of naming the alkyne is to place the locant number of the first carbon of the triple bond in front of the -yne suffix (e.g. pent-2-yne).
3.3. Substituent groups are named and their position is indicated by a locant determined by the numbering system in Step 1 as the triple bond always has priority in numbering.
What are halogenated organic compounds?
These are organic compounds that contain halogens subtituting the hydrogen atoms
What are the naming rules for halogenated organic compounds?
The naming rules are as per the previous hydrocarbons with additional steps:
Note: Bromo, chloro, fluoro, and iodo as prefixes
- Select the longest unbranched hydrocarbon chain. Count the number of C in this chain. The number will decide the stem name of the alkane
- Number the chain from the end that produces the lowest set of numbered positions for all the functional groups
- If more than one type of halogen is present, list in alphabetical order
Note; if the previous rules lead to more than one possible name, then the correct name is the one in which the lowest locant is assigned to the functional group cited first as a prefix
What are carboxylic acids?
These are a class of organic compounds with the general formula R-COOH
They have the carboxyl functional group (-COOH)
We use -oic acid for the suffics for carboxylic acids
It is a terminal functional group, and forms a double bond with O and a single bond with OH before bonding with the rest of a parent chain
What is the general formula for carboxylic acids?
C(n) H(2n+1) COOH
How do you name carboxylic acid groups?
Count how many C’s there are and then put the prefix in front for it.
I.e. ethanoic acid will have two C’s; One c which bonded with 2 O’s and the other one being a ‘CH3’
What are alcohols?
They are a class of organic compounds with the general formula R-OH. Alkanols are alcohols containing only carbon, hydrogen and oxygen
They contain the hydroxyl functional group (-OH)
What is the general formula for alcohols?
C(n) H(2n+1) OH
What are primary, secondary, tertiary alcohols?
Primary alcohols have the C-OH group attached to another C atom
Secondary alcohols have the C-OH group attached to two other C atoms
Tertiary alcohols have the C-OH group attached to three other C atoms
How do you name alcohols?
List any side chains first
then mention the suffix and then the locant for the OH followed by the ol. For example:
REMEMBER THAT AFTER THE SUFFIX YOU HAVE TO MENTION ‘AN’ before the locant
3,3-dimethylbutAN-2-ol
What is an aldehyde?
These contain the carbonyl functional group R-CHO. It involves the carbon having a double bond with O and a single bond with H and then a single bond to the rest of the carbon chain. Thus given by R-CHO
What is the suffix of an aldehyde?
-al
What is an example of an aldehyde?
2,2,3,3-tetramethylbutanal
How do you name an aldehyde?
- When an aldehyde is present in a molecule which also contains
an alcohol functional group the carbonyl is given nomenclature
priority by the IUPAC system. This means that the carbonyl is
given the lowest possible location number and the appropriate
nomenclature suffix is included. - In the case of alcohols the OH is named as
a hydroxyl substituent. However, the l in hydroxyl is generally
removed.
What is a ketone?
It contains the carbonyl functional group C=O (O double bonded to a Carbon atom), this means that it cannot be a terminal functional group
What are the steps in naming a ketone?
Find the longest chain
Find the parent chain and notice the side chains are either halogens or alkyl side groups
List all side chains alphabetically (including halogenated compounds)
Use the suffix for ketone; -one
For example, butan-2-one
Note: still have to use include the ‘an’ into the following letters after the suffix
What is an amine?
These are specialised functional group with NH. The suffix used is -amine
How to name an amine?
Find the parent chain which contains the amine group -NH2
If the other side chains are either halogens or alkyl side groups, the parent chain must have the amine group on the parent chain with the smallest number
All side chains named alphabetically
use prefixes (di, tri, tetra etc) to list position numbers and how many
If there is a side chain on the amine group at either R1 or R2, these side groups are numbered ‘N’ but it is unlikely we get asked these as they are secondary and tertiary amines and we only study primary amines
What are amides?
These are a nitrogen atom attached to a carbonyl group. It involves a double bond to the C with O, and a single bond with C and an N (NH2 (in terms of primary amides))
Since the amide group is at the end of the chain, the C=O carbon must be C1. The suffix used for all amides is -amide
Will still need to include the ‘AN’ after the prefix
When naming the alkyl chains bonded to the N, it is classed as ‘N’ and then use that as a prefix instead of numbers (you mention N before the numbers)
What is the order of functional groups in terms of priority (what comes last) in naming? (highest to lowest)
Carboxylic acid
Ester
Amide
Aldehyde
Ketone
Alcohol
Amine
alkene
Alkyne
Alkyl halides
How does the order of functional groups work?
The higher the priority, the more it is at the back of the formula name. I.e. 2-oxopentanoic acid
where oxo is the prefix for a ketone.
Essentially, when it is the highest priority, it is the last part to be named in the molecule and it will use the suffix such as -oic acid or -ol, however, if there are two different functional groups and the other one is less priority, it will be named before the higher priority functional group using a prefix
What is the suffix/prefix for carboxylic acids?
Suffix: -oic acid
Prefix: Carboxy
Reminder: lower priority uses prefix and is named after the more prioritised one whcih uses the suffix
What is the suffix/prefix for esters?
Suffix: -oate
Prefix: Alkoxycarbonyl
Reminder: lower priority uses prefix and is named after the more prioritised one whcih uses the suffix
What is the suffix/prefix for amides?
Suffix: -amide
Prefix: Amido
Reminder: lower priority uses prefix and is named after the more prioritised one whcih uses the suffix
What is the suffix/prefix for aldehydes?
Suffix: -al
Prefix: Formyl
Reminder: lower priority uses prefix and is named after the more prioritised one whcih uses the suffix
What is the suffix/prefix for ketone?
Suffix: -one
Prefix: Oxo
Reminder: lower priority uses prefix and is named after the more prioritised one whcih uses the suffix
What is the suffix/prefix for alcohols?
Suffix: -ol
Prefix: Hydroxy
Reminder: lower priority uses prefix and is named after the more prioritised one whcih uses the suffix
What is the suffix/prefix for amine?
Suffix: -Amine
Prefix: Amino
Reminder: lower priority uses prefix and is named after the more prioritised one whcih uses the suffix
What is the suffix/prefix for alkene?
Suffix: -ene
Prefix: Alkenyl
A bit sketch
Reminder: lower priority uses prefix and is named after the more prioritised one whcih uses the suffix
What is the suffix/prefix for alkyne?
Suffix: -yne
Prefix: Alkynyl
A bit sketch
Reminder: lower priority uses prefix and is named after the more prioritised one whcih uses the suffix
What is the suffix/prefix for alkyl halides?
Suffix: -
Prefix: Halo
Reminder: lower priority uses prefix and is named after the more prioritised one whcih uses the suffix
What is an ester?
Esters are derived from carboxylic acids, and thus have the C=O and C-O bond. However, the H in the group is replaced by an alkyl group.
For example, normally a carboxylic acid will have the C=O and C-O-H bond at the end. However, there is only the C=O bond and C - O - (alkyl chain). Note that others chains can be connected to the C which is bonded to the 2 O’s
How is an ester named?
first we name the alkyl group which is BONDED TO THE O; i.e. if there are 3 carbons which are bonded which is connected to the O, it will be named ‘propyl’
This is followed by looking at how many other C’s there are. Count the number of C’s bonded to the C which is bonded to the 2 O’s and include the C which is bonded to the 2 O’s in the counting. The number then has the suffix -oate at the end.
For example, there could be propyl methanoate. Where, there are 3 alkyl groups bonded to the O, and only one hydrogen bonded to one carbon which is bonded to the 2 O’s
What is an ether?
Dont thinkwe need to know?
What is a structural isomer?
Structural isomers are used to describe molecules that have the same molecular formula but atoms that make up the molecules are arranged differently along the parent carbon chain structure, thus having different structural formula.
What are chain isomers?
Chain isomers are two or more compounds with similar chemical formulas but distinct carbon atom arrangements in straight or branched chains
We can say they are a chain isomer if;
They have the same molecular formula
They must differ in their connectivity of carbon atoms to the parent carbon chain
What are position isomers? Conditions?
Positional isomers are constitutional isomers that have the same carbon skeleton and the same functional groups but differ from each other in the location of the functional groups on or in the carbon chain
The conditions for position isomers are:
Same molecular formula
Same carbon structure in terms of parent carbon chain length
Isomers that differ in their position of double and triple carbon bonds in carbon structure can be considered position isomers
What are functional group isomers? Conditions?
Functional group isomers are molecules with the same molecular formula, but different functional groups. I.e. a ketone having the same formula as a aldehyde
The conditions for a functional group isomer is:
Must have same molecular formula (may or may not have the same parent carbon chain length)
Due to isomers differing in their arrangement of atoms, this can result in isomers having different functional groups
So functional group isomers are molecules in different homologous series as they have different functional groups
WHat are saturated vs unsaturated hydrocarbons?
Saturated hydrocarbons, i.e. alkanes, are those whereby there are only single covalent bonds between carbon atoms in the hydrocarbon molecule.
Comparatively, unsaturated hydrocarbons, i.e. alkenes and alkynes, are those whereby there are double or triple bonds between carbon atoms in the hydrocarbon.
