Organic Chemistry: Functional Groups and Benzene Derivatives Nomenclature

Comprehensive vocabulary flashcards covering the structures, examples, IUPAC rules, and common names for oxygen- and nitrogen-containing organic functional groups and benzene derivatives.

Alkyl Halides

A class of hydrocarbons formed when an atom such as chlorine is attached as a functional group to an alkane.

$R$ Group

A notation commonly used in discussing functional groups to represent the rest of the molecule to which the functional group is attached.

Hydroxyl Group

A common oxygen-containing functional group with the formula $R-OH$, present in alcohols and carboxylic acids, and designated with the prefix hydroxy-.

Carbonyl Group

A common oxygen-containing functional group with the structure $R-C=O$, found in aldehydes, ketones, and carboxylic acids.

Alcohol

An organic compound containing a hydroxyl group ($R-O-H$), named by changing the root alkane ending from -ane to the suffix -ol, exemplified by ethanol ($CH_3CH_2OH$).

Aldehyde

An organic compound with a carbonyl group positioned at the end of the hydrocarbon chain ($R-C(=O)H$), named with the suffix -al or prefixes oxo-/formyl-, exemplified by ethanal ($CH_3CHO$).

Ketone

An organic compound containing a carbonyl group located in the middle of the hydrocarbon chain ($R-C(=O)R'$), named with the suffix -one or prefix oxo-, exemplified by propanone ($CH_3COCH_3$).

Carboxylic Acid

An organic compound featuring both a carbonyl and a hydroxyl group at the end of the carbon chain ($R-COOH$), named with the suffix -oic acid, exemplified by ethanoic acid ($CH_3COOH$).

Ether

A molecule whose structure is very similar to water, featuring an oxygen atom bonded to two alkyl groups ($R-O-R$), which can either be the same or different.

IUPAC Naming of Ethers

The system of changing the -ane ending of the smaller hydrocarbon name to -oxy (the side chain) and joining it directly to the alkane name of the longer hydrocarbon.

Ester

An organic compound containing the ester functional group ($R-O-C(=O)R$ or $RO-CR$), exemplified by ethyl ethanoate ($CH_3CH_2OC(=O)CH_3$).

Amine

A nitrogen-containing functional group with the general structure $R-NH_2$, exemplified by methanamine ($CH_3NH_2$).

Amide

A nitrogen-containing functional group containing a carbonyl group bonded to nitrogen ($R-C(=O)NH_2$), exemplified by ethanamide ($CH_3CONH_2$).

Monosubstituted Benzene Nomenclature

The standard naming convention where the name of the substituent group is prefixed directly before the word benzene, such as in fluorobenzene, bromobenzene, chlorobenzene, and nitrobenzene.

Benzoic Acid

A common benzene derivative containing a carboxylic acid group ($-COOH$) bonded directly to the benzene ring.

Phenol

A common benzene derivative containing a hydroxyl group ($-OH$) bonded directly to the ring; also known by the IUPAC name hydroxybenzene.

Aniline

A common benzene derivative containing an amino group ($-NH_2$) bonded directly to the ring; also known as aminobenzene.

Toluene

A common benzene derivative containing a methyl group ($-CH_3$) bonded directly to the ring; also known as methylbenzene.

Polysubstituted Benzene Numbering Rule

The rule specifying that if several identical groups are substituted on a benzene ring, each is given a position number to generate a sequence yielding the lowest combination of numbers.

Alkane: General Formula and IUPAC Suffix

A saturated hydrocarbon containing only single $C-C$ and $C-H$ bonds, conforming to the formula $C_nH_{2n+2}$, named using the suffix -ane.

Alkene: Distinguishing Feature and IUPAC Suffix

An unsaturated hydrocarbon containing one or more carbon-carbon double bonds ($C=C$), named using the suffix -ene with a locant number denoting the lowest-numbered double-bonded carbon.

Alkyne: Distinguishing Feature and IUPAC Suffix

An unsaturated hydrocarbon containing one or more carbon-carbon triple bonds ($C\equiv C$), named using the suffix -yne with a locant number denoting the lowest-numbered triple-bonded carbon.

Cycloalkane: Structure and Naming Rule

A saturated hydrocarbon forming a closed ring of carbon atoms (formula $C_nH_{2n}$), named by prefixing the parent alkane name with cyclo-.

Parent Chain Selection: Ring vs. Open Chain

The parent structure is selected based on whichever contains the greater number of carbons: if the ring has more carbons, it serves as the parent ring; if the acyclic chain has more carbons, the ring becomes a cycloalkyl side group.

IUPAC Lowest Locant Rule

The principle that the parent carbon chain must be numbered from the direction that assigns substituents the lowest possible locant numbers at the first point of difference, regardless of substituent identity.

Substituent Alphabetization Rule

Substituents are organized alphabetically in the final compound name; numerical prefixes like di-, tri-, sec-, and tert- are ignored, whereas prefixes like iso-, neo-, and cyclo- are alphabetized.

Multiplying Prefixes Rule

When two or more identical substituents are attached to a chain, prefixes like di-, tri-, or tetra- are applied, and every individual substituent must have its own locant number separated by commas.

Structural (Constitutional) Isomers

Molecules that share the exact same molecular formula but have different atomic connectivities and bonding orders.

Geometric ($cis/trans$) Isomers

Stereoisomers with identical molecular formulas and atomic connectivity that differ in the 3D arrangement of groups across a rigid bond with restricted rotation, such as a double bond ($C=C$) or a ring system.

Identifying Identical vs. Isomeric Molecules

Two molecular drawings are identical if rotating the whole molecule or rotating around single ($\sigma$) bonds produces the exact same spatial connectivity and systematic IUPAC name.

Ortho, Meta, and Para ($o-$, $m-$, $p-$) Designations

Common positional prefixes used exclusively for disubstituted benzene rings: ortho- ($1,2-$ relative positions), meta- ($1,3-$ relative positions), and para- ($1,4-$ relative positions).

Toluene: Required Group and IUPAC Name

A benzene ring bonded directly to a single methyl group ($-CH_3$); also known systematically as methylbenzene.

Phenol: Required Group and IUPAC Name

A benzene ring bonded directly to a hydroxyl group ($-OH$); also known systematically as hydroxybenzene.

Aniline: Required Group and IUPAC Name

A benzene ring bonded directly to an amino group ($-NH_2$); also known systematically as aminobenzene.

Benzoic Acid: Required Functional Group

A benzene ring bonded directly to a carboxylic acid group ($-COOH$).

Polysubstituted Benzene Numbering Rule

When three or more substituents are present on a benzene ring, positions are numbered $1$ through $6$ to yield the lowest possible set of locants at the first point of difference, listed in alphabetical order.

Alkyl Halides (Haloalkanes): Functional Group and Naming

Hydrocarbons containing one or more halogens ($F$, $Cl$, $Br$, $I$) bonded to an $sp^3$ carbon, named with substituent prefixes fluoro-, chloro-, bromo-, or iodo-.

Alcohol: Functional Group, Suffix, and Prefix

An organic compound containing a hydroxyl group ($-OH$) bonded to a saturated carbon; named with the primary suffix -ol, or with the prefix hydroxy- when outranked by a higher-priority group.

Carbonyl Group: Structure and Compound Types

A divalent functional group consisting of a carbon double-bonded to an oxygen ($C=O$); serves as the core functional unit of aldehydes, ketones, carboxylic acids, esters, and amides.

Carbonyl Placement: Aldehyde vs. Ketone

An aldehyde contains a carbonyl group bonded to at least one hydrogen atom at the end of a chain ($R-CHO$), whereas a ketone contains a carbonyl group located between two interior carbon atoms ($R-CO-R'$).

Aldehyde: Nomenclature Suffix and Prefixes

Named with the suffix -al; when treated as a subordinate substituent or attached to a ring, it is designated with the prefixes oxo- (for $=O$) or formyl- (for $-CH=O$).

Ketone: Nomenclature Suffix and Prefix

Named with the suffix -one along with a locant number for the carbonyl carbon; designated with the prefix oxo- when another functional group takes priority.

Carboxylic Acid: Structural Requirements and Suffix

Contains a terminal carbonyl group bonded directly to a hydroxyl group ($-COOH$ or $-C(=O)OH$); named systematically by replacing the alkane ending with -oic acid.

Ether: Structural Feature and IUPAC Naming Rule

Contains an oxygen atom single-bonded between two alkyl groups ($R-O-R'$); always named as a side group by changing the smaller alkyl group's ending to -oxy (alkoxy substituent) joined to the longer parent alkane chain.

Ester: Structure and Nomenclature Rule

Contains a carbonyl bonded to an alkoxy group ($R-C(=O)O-R'$); named by stating the alkyl group attached to the single-bonded oxygen first, followed by the parent carboxylate chain ending in -oate.

Amine vs. Amide: Structural Distinction

An amine consists of a nitrogen atom bonded exclusively to alkyl chains or hydrogens ($R-NH_2$, $R_2NH$, $R_3N$), while an amide consists of a nitrogen atom bonded directly to a carbonyl carbon ($R-C(=O)NR'_2$).

Amine: Nomenclature Suffix and Prefix

Named with the suffix -amine (e.g., methanamine); when present as a subordinate substituent, it is designated by the prefix amino-.

Amide: Nomenclature Suffix

Derived from carboxylic acids by replacing the $-OH$ with a nitrogen group; named by dropping the -oic acid ending of the parent carboxylic acid and adding the suffix -amide.