Organic Chemistry/Glossary

> Glossary

A

Acetal - a molecule with two single bonded oxygens attached to the same carbon atom

Acetyl - a functional group with chemical formula -COCH3

Achiral - a group containing atleast two identical substituents

Acid anhydride - hydrocarbon containing two carbonyl groups.Acyl group attached with carboxylate group. eg RCOOCOR'

Acid halide - acyl group with any halogen attached with carbon of carbonyl group. eg RCO-X(X=F,Cl,Br,I).

Acidity constant K_a -

Activating group - any group which activates a molecule by increasing positive or negative charge on a carbon atom. Mainly towards neucleophilic or electrophilic substitution reactions.

Activation energy - the energy required for reactants to cross energy barrier to undergo any chemical change; denoted by E_a.

Acyl group - a group having an alkyl or aryl group with a carbonyl group RCO-

Adam's catalyst - a catalyst for hydrogenation and hydrogenolysis in organic synthesis. Also known as platinum dioxide

Addition reaction - a reaction where a product is created from the coming together of 2 reactants.

Alcohol - a saturated hydrocarbon chain with an -OH functional group.

Aldehyde - a hydrocarbon containing at least one carbonyl group having one hydrogen attached to it.(>C=O)

Aldol reaction - a reaction of two aldehydes yielding a product with both an aldehyde(>C=O) and an alcohol() group.

Aliphatic - A non-cyclic, non-aromatic, hydrocarbon chain (e.g. alkanes, alkenes, and alkynes)

Alkane - A hydrocarbon with all the carbon-carbon bonds are single bonds.

Alkene - A hydrocarbon with at least one carbon-carbon bond is a double-bond.

Alkoxide ion - The conjugate base of an alcohol without the terminal H atom. For any alcohol R-OH, the corresponding alkoxide form is R-O^-.

Alkyl - A hydrocarbon having formula C_nH_2n+1

Alkylation - Addition of alkyl group in a compound.

Alkyne - An unsaturated hydrocarbon containog triple bond.and having general formula C_nH_2n-2

Allyl - An alkene hydrocarbon group with the formula H2C=CH-CH2-

α Position - Carbon attached to a functional group is called α-carbon and the position is known as α position.

α-carbon - Carbon attached to a functional group is called α-carbon

Amide - A hydrocarbon containing amine group attached to acyl group. eg.- RCONH₂

Amine - A simple hydrocarbon containing atleast one -NH₂ group.

Amino Acid - A fundamental unit of polypeptides or proteins.having general formula-COOHRCHNH₂.eg.- glysine, alanine etc.

Anti conformation -

Anti periplaner -

Anti stereochemistry -

Anti bonding molecular orbital - Molecular orbitals having higher energy than bonding molecular orbitals after combination of atomic orbitals.denoted by an astric over Sigma or pi notations.

Arene - Another name for an aromatic hydrocarbon.

Aromaticity - A chemical property in which a conjugated ring of unsaturated bonds, lone pairs, or empty orbitals exhibit a stabilization stronger than would be expected by the stabilization of conjugation alone.

Atomic mass - Total no of nucleon i.e. number of proton and number of neutrons. Atomic mass is denoted by A.

Atomic number - Total no. of protons is called the atomic number.

Axial bond - The bond parallel or antiparallel to axial coordinate passing center of gravity.

Azide synthesis - Dutt-Wormall reaction in which a diazonium salt reacts with a sulfonamide first to a diazoaminosulfinate and then on hydrolysis the azide and a sulfinic acid.

Azo compound - A compound containing -N=N group.

B

Benzoyl Group - The acyl of benzoic acid, with structure C6H5CO-

Benzyl Group - The radical or ion formed from the removal of one of the methyl hydrogens of toluene (methylbenzene).

Benzylic -

β position -

β-carbon -

Bicylcoalkane - A compound containing two cyclic rings.

Bimolecular reaction - A second order reaction where the concentration of two compounds determine the reaction rate.

Boat cyclohexane - A less-stable conformation of cyclohexane that somewhat resembles a boat.

Bond - The attractive forces that create a link between atoms. Bonds may be covalent or ionic.

Bond angle - The angle formed between three atoms across at least two bonds.

Bond length - The average distance between the centers of two atoms bonded together in any given molecule.

Bond strength - The degree to which each atom linked to a central atom contributes to the valency of this central atom.

Bonding molecular orbital -

Bromonium ion -

Brønsted-Lowry Acid -

Brønsted-Lowry Base -

C

Cahn-Ingold-Prelog priorities - A rule for assigning priorities to substituents off of carbon in a double-bond or in a chiral center.

Carbocation -

Carbonyl group - A functional group composed of a carbon atom double-bonded to an oxygen atom: C=O.

Carboxylation - A chemical reaction in which a carboxylic acid group is introduced in a substrate.

Carboxylic acid - An organic acid characterized by the presence of a carboxyl group.

Chain reaction - A sequence of reactions where a reactive product or by-product causes additional reactions to take place

Chair cyclohexane -

Chiral - A term used to describe an object that is non-superposable on its mirror image

Chiral center - A carbon atom bonded to four different groups

Chromatography - The process of separating compounds such as a dye into its constituents

Cis-trans isomers -

Claisen condensation reaction -

Claisen rearrangement reaction -

Concerted -

Configuration - the permanent geometry of a molecule that results from the spatial arrangement of its bonds.

Conformation -

Conformer -

Conjugate acid -

Conjugate base -

Conjugation - A system of atoms covalently bonded with alternating single and multiple (e.g. double) bonds (e.g., C=C-C=C-C).

Covalent bond - A form of chemical bonding that is characterized by the sharing of pairs of electrons between atoms.

Cracking - The process whereby complex organic molecules such as heavy hydrocarbons are broken down into simpler molecules (e.g. light hydrocarbons) by the breaking of carbon-carbon bonds.

Cycloaddition reaction -

Cycloalkane - An alkane that has one or more rings of carbon atoms in the chemical structure of its molecule.

D

Debye -

Decarboxylation -

Delocalization - The ability of electrons to spread out among pi bonds to provide stabilization to electronically unstable areas of a molecule.

Dextrorotatory -

Diastereomers - Two or more isomers of a molecule which are not enantiomers of one another.

1,3 Diaxial interaction - The steric intereaction between two methyl or larger groups attached at the 1 and 3 cis positions of cyclohexanes. The cyclohexane is in a higher energy state in the ring flip conformation that results in both 1 and 3 positions being axial due to steric strain between the 2 groups. This strain does not exist when hydrogens are bonded at these positions.

Diels-Alder reaction -

Dienophile -

Dipolar -

Dipole moment -

Disulfide -

Downfield - A term used to describe the left direction on NMR charts. A peak to the left of another peak is described as being downfield from the peak.

E

E geometry -

E1 reaction -

E2 reaction -

Eclipsed conformation -

Eclipsing strain -

Electron - An elementary subatomic particle that carries a negative electrical charge and occupies an electron shell outside the atomic nucleus.

Electron configuration - The arrangement of electrons in an atom or molecule

Electron-dot structure -

Electron shell - The orbit followed by electrons around an atomic nucleus. The atom has a number of shells and they are normally labelled K, L, M, N, O, P, and Q.

Electronegativity - The ability of an atom to attract electrons towards itself in a covalent bond.

Electrophile - Literally, electron lover. A positively or neutrally charged reagent that forms bonds by accepting electrons from a nucleophile. Elecrophiles are Lewis Acids.

Electrophilic addition reaction -

Electrophilic aromatic substitution -

Elimination reaction - A reaction where atoms and/or functional groups are removed from a reactant.

Endergonic - In an endergonic process, work is done on the system, and ΔG⁰ > 0, so the process is nonspontaneous. An exergonic process is the opposite: ΔG⁰ < 0, so the process is spontaneous.

Endothermic - An endothermic reaction is a chemical reaction that absorbs heat, and is the opposite of an exothermic reaction.

Enol - An alkene with a hydroxyl group affixed to one of the carbon atoms composing the double bond.

Enolate ion -

Entgegen - German word meaning "opposite". Represented by E in the E/Z naming system of alkenes.

Enthalpy -

Entropy -

Equatorial bond -

Ester - An inorganic or organic acid in which at least one -OH (hydroxyl) group is replaced by an -O-alkyl (alkoxy) group.

Ether - An organic compound which contains an ether group — an oxygen atom connected to two (substituted) alkyl or aryl groups — of general formula R–O–R'.

Exergonic -

Exothermic - An exothermic reaction is a chemical reaction that releases heat, and is the opposite of an endothermic reaction.

F

Fingerprint region -

First order reaction - A reaction whose rate is determined by the concentration of only one of its reactants leading to a reaction rate equation of $Rate=k[X]$

Fischer projection -

Formal Charge -

Friedel-Crafts reaction -

Functional group - This is a specific group of atoms within a molecule that is responsible for the characteristic chemical reactions of that molecule. The same functional group will undergo the same or similar chemical reaction(s) regardless of the size of the molecule it is a part of.

G

Geminal -

Gibbs free energy -

Gilman reagent -

Glycol - A chemical compound containing two hydroxyl groups (-OH groups). Also known as a Diol.

Glycolysis - The metabolic pathway that converts glucose, C₆H₁₂O₆, into pyruvate, C₃H₅O₃. This process usually occurs outside the mitochondria of a cell to help produce energy.

Grignard reagent -

Ground state - In electrons, the state where they have the least energy. Electrons that gain energy get "excited" and leave the ground state, now able to do more work. Moving electrons out of their ground state is a key part of photosynthesis, where plants create sugar from the sun, carbon dioxide, and water.

H

Halohydrin formation -

Hammond postulate -

Hemiacetal -

Hemiaminal -

Heterocycle - A cyclic molecule with more than 2 types of atoms as part of the ring. (e.g. Furan, a 5-membered ring with four carbons and one oxygen, or a Pyran, a 6-membered ring with five carbons and one oxygen)

HOMO - Acronym for Highest Occupied Molecular Orbital.

Homolytic cleavage - Where bond breaks leaving each atom with one of the bonding electrons, producing two radicals.

Hybrid orbital -

Hydration - A chemical reaction in which a hydroxyl group (OH-) and a hydrogen cation (an acidic proton) are added to the two carbon atoms bonded together in the carbon-carbon double bond which makes up an alkene functional group.

Hybride shift -

Hydroboration - A reaction adding BH₃ or B₂H₆ or an alkylborane to an alkene to produce intermediate products consisting of 3 alkyl groups attached to a boron atom. This molecule is then used in other reactions, for example, to create an alcohol by reacting it with H₂O₂ in a basic solution.

Hydrocarbon - A molecule consisting of hydrogens and carbons.

Hydrogen bond -

Hydrogenation - Addition of a hydrogen atoms to an alkene or alkane to produce a saturated product.

Hydrophilic - literally, "water loving". In chemistry, these are molecules that are soluble in water.

Hydrophobic - literally, "water fearing". In chemistry, molecules that aren't soluble in water.

Hydroxylation - A chemical process that introduces one or more hydroxyl groups (-OH) into a compound (or radical) thereby oxidizing it.

Hyperconjugation -

I

Imide -

Imine -

Infrared spectroscopy -

Intermediate -

Isomer - Compounds with the same molecular formula but different structural formulae. There are two main forms of isomerism: structural isomerism and stereoisomerism.

Isotope - The different types of atoms of the same chemical element, each having a different atomic mass (mass number). Isotopes of an element have nuclei with the same number of protons (the same atomic number) but different numbers of neutrons.

IUPAC - Acronym for International Union of Pure and Applied Chemistry.

IUPAC Nomenclature - The international standard set of rules for naming molecules.
(Available Here)

K

Kekulé structure -

Keto-enol tautomerism -

Ketone - The functional group characterized by a carbonyl group (O=C) linked to two other carbon atoms, or a chemical compound that contains a carbonyl group

L

Leaving group -

Levorotatory -

Lewis acid - A reagent that accepts a pair of electrons form a covalent bond. (see also Lewis Acids and Bases)

Lewis base - A reagent that forms covalent bonds by donating a pair of electrons. (see also Lewis Acids and Bases)

Lewis structure -

Lindlar catalyst -

Line-bond structure -

Lone pair electrons -

LUMO - Acronym for Lowest Unoccupied Molecular Orbital

M

Markovnikov's rule - States that "when an unsymmetrical alkene reacts with a hydrogen halide to give an alkyl halide, the hydrogen adds to the carbon of the alkene that has the greater number of hydrogen substituents, and the halogen to the carbon of the alkene with the fewer number of hydrogen substituents."

Mass number - The total number of protons and neutrons (together known as nucleons) in an atomic nucleus

Mass spectrometry -

Mechanism -

Meso compound -

Meta -

Methylene group -

Molality - A measure of the concentration of a solute in a solvent given by moles of solute per kg of solvent.

Molarity - A measure of the concentration, given by moles of solute per liter of solution (solute and solvent mixed).

Mole - A measure of a substance that is approximately Avogadro's Number (6.022×10²³) of molecules of the substance. More simply, calculate the molecule's atomic mass and that many grams of the substance is a mole.

Molecule -

Monomer - A small molecule that may become chemically bonded to other monomers to form a polymer.

N

Nitrile - Any organic compound which has a -C≡N functional group.

NMR - See Nuclear magnetic resonance.

Non-bonding electrons -

Normality -

Nuclear magnetic resonance -

Nucleophile - Literally, nucleus lover. A negatively or neutrally charged reagent that forms a bond with an electrophile by donating both bonding electrons. Nucleophiles are Lewis Bases.

Nucleophilic addition reaction -

Nucleophilic aromatic substitution reaction -

Nucleophilic substitution reaction - A reaction in which a halide is removed from a molecule and replaced with a nucleophile.

Nucleophilicity -

O

Optical isomer -

Optical activity -

Orbital -

Ortho -

Oxidation -

Oxime -

Oxymercuration reduction reaction -

P

Para -

Pauli exclusion principle -

Pericyclic reaction -

Periplanar -

Peroxide -

Peroxyacid -

Phenol - A toxic, colourless crystalline solid with the chemical formula C₆H₅OH and whose structure is that of a hydroxyl group (-OH) bonded to a phenyl ring. It is also known as carbolic acid,

Phenyl - A functional group with the formula -C₆H₅

Pi bond -

Polar aprotic solvent -

Polar covalent bond -

Polar protic solvent -

Polar reaction -

Polarity -

Polarizability -

Polymer - A large molecule (macromolecule) composed of repeating structural units (monomers) typically connected by covalent chemical bonds.

Primary -

Prochiral -

Prochirality center -

Protic solvent -

Q

R

R group -

R,S convention -

Racemic mixture -

Radical -

Radical reaction -

Rate constant -

Rate equation -

Rate-limiting step -

re face -

Reducation -

Regiochemistry -

Regioselectivity -

Resonance form -

Resonance hybrid -

Ring-flip -

S

Saponification - The hydrolysis of an ester under basic conditions to form an alcohol and the salt of a carboxylic acid.

Saturated - Saturation in a general means possessing a maximal quantity. A compound is commonly called saturated when it has no double or triple bonds. Saturated can refer to a maximal amount of a solute which can dissolve in a solution. Whether the context is chemical bonding or solutions will determine which meaning is appropriate.

Saytzeff's Rule - See Zaitsev's rule

Second order reaction - A reaction whose rate is dependent on the concentration of two reactants, leading to a reaction rate of $Rate=k[X][Y]$

Secondary -

si face -

Side chain -

Sigma bond -

Simmons-Smith reaction -

S_N1 reaction -

S_N2 reaction -

Solvation -

Solvent -

sp orbital -

sp² orbital -

sp³ orbital -

Spin-spin splitting -

Staggered conformation -

Stereochemistry -

Stereoisomer -

Steric hinderance -

Steric strain -

Substitution reaction - Reactions where one functional groups is replaced with another functional group.

Symmetry plane -

Syn addition -

Syn periplanar -

T

Tautomers -

Tertiary - adjective describing a third occurrence or position

Thioester -

Thiol - A compound that contains the functional group composed of a sulfur atom and a hydrogen atom (-SH).

Thiolate ion -

Torisional strain -

Tosylate -

Transition state -

Twist-boat conformation -

U

Ultraviolet spectroscopy -

Unsaturated - Unsaturated commonly describes a situation in which a compound contains double or triple bonds.

Upfield - A term used to describe the right direction on NMR charts. A peak to the right of another peak is described as being upfield from the peak.

V

Valence bond theory -

Valence electrons -

Valence shell -

Van der Waals forces -

Vicinal -

Vinyl - An organic compound that contains a vinyl group (also called ethenyl), −CH=CH2.

Vinylic -

W, X, Y, Z

Zaitsev's rule - In elimination reactions, the major reaction product is the alkene with the more highly substituted double bond. This most-substituted alkene is also the most stable.

Zussamen - German word meaning "together". Represented by Z in the E/Z naming system of alkenes. Simple mnemonic, Z=Zame Zide (Same Side).