Organic Chemistry: A Short Course - Thirteenth Edition

Flashcards covering key vocabulary from the Organic Chemistry: A Short Course textbook, Thirteenth Edition, across various chapters including bonding, isomerism, alkanes, alkenes, alkynes, aromatic compounds, stereoisomerism, organic halogen compounds, alcohols, phenols, thiols, ethers, epoxides, aldehydes, ketones, carboxylic acids and their derivatives, amines, heterocyclic compounds, synthetic polymers, lipids, detergents, carbohydrates, amino acids, peptides, proteins, nucleotides, and nucleic acids.

Valence electrons

Electrons in the outer shell of an atom, involved in bonding.

Ionic bonds

Bonds formed by electron transfer from an electropositive atom to an electronegative atom.

Covalent bonds

Bonds formed by sharing electrons between atoms with similar electronegativities.

Single bond

The sharing of one electron pair between two atoms.

Bond length

The specific distance between the nuclei of two bonded atoms.

Bond energy

The energy required to break a bond or released upon its formation.

Pure covalent bonds

Covalent bonds where electrons are shared equally between atoms.

Polar covalent bonds

Covalent bonds where electrons are displaced toward the more electronegative element.

Multiple bonds

Bonds consisting of two or three electron pairs shared between atoms (double or triple bonds).

Structural (or constitutional) isomers

Compounds with the same molecular formulas but different structural formulas (different arrangements of atoms).

Catenation

The capacity of carbon atoms to be arranged in many different ways: continuous chains, branched chains, and rings.

Formal charge

The number of valence electrons in the neutral atom minus the sum of the number of unshared electrons and half the number of shared electrons.

Resonance

Occurs when two or more structures for a molecule or ion with the same arrangement of atoms but different arrangements of electrons can be written.

Contributing structures (Resonance structures)

Different electron arrangements for a molecule or ion, drawn with a double-headed arrow (↔) between them. The true structure is a hybrid.

Curved arrow

Used by organic chemists to show the movement of an electron pair.

Sigma (σ) bond

Formed between atoms by the overlap of two atomic orbitals along the line that connects the atoms.

sp3-hybridized orbitals

Orbitals used by carbon to form four sigma bonds, directed towards the corners of a tetrahedron.

Tetrahedral carbon

A carbon atom at the center of a tetrahedron with four substituents at its corners, having H–C–H bond angles of 109.5° (e.g., methane).

Acyclic compounds

Carbon compounds classified as not cyclic.

Carbocyclic compounds

Carbon compounds containing rings of carbon atoms.

Heterocyclic compounds

Carbon compounds containing at least one ring atom that is not carbon.

Functional group

A group of atoms responsible for the characteristic reactions of a particular compound.

Electronegativity

The measure of an atom's ability to attract electrons in a chemical bond.

Electropositivity

The tendency of an atom to donate electrons in a chemical bond.

Nucleus

The dense, central core of an atom containing protons and neutrons.

Electrons

Negatively charged subatomic particles orbiting the nucleus.

Protons

Positively charged subatomic particles located in the nucleus.

Neutrons

Neutral subatomic particles located in the nucleus.

Atomic number

The number of protons in an atom's nucleus.

Atomic weight

The average mass of an atom of an element, including isotopes.

Shells

Energy levels where electrons orbit the nucleus.

Orbitals

Regions around the nucleus where electrons are likely to be found.

Valence

The combining capacity of an element, determined by the number of bonds it can form.

Kernel

The nucleus and inner-shell electrons of an atom, excluding the valence electrons.

Radical

An atom, molecule, or ion with an unpaired valence electron.

Nonbonding (unshared) electron pair

A pair of valence electrons not involved in bonding.

Molecular formula

A chemical formula that shows the number and types of atoms in a molecule.

Continuous chain

A straight arrangement of carbon atoms in a molecule.

Branched chain

An arrangement of carbon atoms in a molecule with side chains branching off the main chain.

Alkene

A hydrocarbon containing at least one carbon-carbon double bond.

Alkyne

A hydrocarbon containing at least one carbon-carbon triple bond.

Alcohol

An organic compound containing a hydroxyl (-OH) group attached to an alkyl group.

Ether

An organic compound containing an oxygen atom bonded to two alkyl or aryl groups (R-O-R').

Aldehyde

An organic compound containing a carbonyl group (C=O) bonded to a hydrogen atom and an alkyl or aryl group (-CHO).

Ketone

An organic compound containing a carbonyl group (C=O) bonded to two alkyl or aryl groups (R-CO-R').

Carboxylic acid

An organic compound containing a carboxyl group (-COOH).

Ester

An organic compound derived from a carboxylic acid where the hydrogen of the hydroxyl group is replaced by an alkyl or aryl group (-COO-R').

Amine

An organic compound derived from ammonia, where one or more hydrogen atoms are replaced by alkyl or aryl groups.

Nitrile

An organic compound containing a cyano group (-C≡N).

Amide

An organic compound containing a carbonyl group bonded to a nitrogen atom (-CO-NH2).

Thiol

An organic compound containing a sulfhydryl group (-SH).

Thioether

An organic compound containing a sulfur atom bonded to two alkyl or aryl groups (R-S-R').

Saturated hydrocarbon

Hydrocarbons containing only single carbon-carbon bonds.

Alkane

Acyclic saturated hydrocarbons (contain only single bonds).

Cycloalkane

Saturated hydrocarbons that have carbon rings.

Homologous series

A series of organic compounds with the same general formula, usually varying by a -CH2- unit.

Methylene group

A -CH2- group, characteristic of a homologous series.

IUPAC nomenclature system

The International Union of Pure and Applied Chemistry (IUPAC) system for naming organic compounds.

Alkyl groups

Alkanes minus one hydrogen atom, named by changing the -ane ending to -yl.

R (symbol in organic chemistry)

Stands for any alkyl group.

Conformations

Different structures that are interconvertible by rotation about single bonds.

Staggered conformation

A conformation where substituents on adjacent carbons are as far apart as possible (more stable).

Eclipsed conformation

A conformation where substituents on adjacent carbons are directly aligned (less stable).

Dash-wedge projection

A way to represent 3D molecular structures on a 2D surface using dashes (away) and wedges (towards).

Newman projection

A way to visualize the conformation of a molecule by looking down a carbon-carbon bond.

Sawhorse projection

A way to represent the 3D arrangement of atoms in a molecule, showing the C-C bond at an angle.

Rotational isomers (Rotamers)

Different conformations of a molecule that result from rotation about single bonds.

Chair conformation

The most stable conformation of cyclohexane, resembling a lawn chair.

Axial bonds

Bonds in cyclic compounds that are perpendicular to the mean carbon plane.

Equatorial bonds

Bonds in cyclic compounds that are roughly in the mean carbon plane.

Geometric (cis-trans) isomerism

A type of stereoisomerism where substituents on a ring or double bond can be on the same (cis) or opposite (trans) sides.

Stereoisomers

Isomers with the same order of atom attachments but different arrangements of atoms in space.

Configurational isomers

Stereoisomers that are not interconvertible by bond rotation.

Substitution reaction

A reaction in which one atom or group in a molecule is replaced by another atom or group.

Halogenation

A reaction in which hydrogen atoms in an alkane are replaced by halogens.

Chlorination

Halogenation specifically with chlorine.

Bromination

Halogenation specifically with bromine.

Free-radical chain reaction

A reaction mechanism involving species with unpaired electrons (free radicals) that proceeds through initiation, propagation, and termination steps.

Chain initiation

The step in a chain reaction where free radicals are first formed.

Propagation

Steps in a chain reaction where a free radical reacts with a stable molecule to form a new free radical and a new molecule.

Termination

Steps in a chain reaction where two free radicals combine to form a stable molecule, ending the chain.

Combustion

The burning of alkanes in air, yielding carbon dioxide and water (complete combustion) or carbon monoxide/other forms of carbon (incomplete combustion).

Unsaturated hydrocarbon

Hydrocarbons containing one or more carbon-carbon double or triple bonds.

Diene

A hydrocarbon containing two carbon-carbon double bonds.

Conjugated double bonds

Double bonds separated by a single bond (alternating single and double bonds).

Cumulated double bonds

Double bonds sharing a common carbon atom (adjacent double bonds).

Isolated double bonds

Double bonds separated by two or more single bonds.

Vinyl group

A -CH=CH2 group.

Allyl group

A -CH2-CH=CH2 group.

Trigonal carbon

A carbon atom with three substituents and sp2 hybridization, typically found in double bonds, with bond angles of 120°.

sp2 hybridization

Hybridization involving one s and two p orbitals, resulting in three trigonal planar hybrid orbitals and one unhybridized p orbital.

Restricted rotation

Rotation about a carbon-carbon double bond or within a ring that is not freely possible.

π (pi) bond

A bond formed by lateral overlap of aligned p orbitals, found in double and triple bonds.

Addition reaction

A reaction where atoms or groups are added to a double or triple bond.

Markovnikov's rule

In the addition of HX to an unsymmetrical alkene, the hydrogen atom adds to the carbon atom of the double bond that already has more hydrogen atoms.

Electrophile (E+)

An electron-deficient species that seeks an electron pair to form a new bond.

Nucleophile (Nu:–)

An electron-rich species that donates an electron pair to form a new bond.

Symmetrical alkene

An alkene where both carbon atoms of the double bond have identical substituents.

Unsymmetrical alkene

An alkene where the two carbon atoms of the double bond have different substituents.

Carbocation

A positively charged organic species with a carbon atom bearing three bonds and a positive charge.