Organic Chemistry Flashcards

Achiral Molecule

A molecule that can be superimposed over it's mirror image.

Chiral Centre

A molecule with four non equivalent groups that is not superimpossible on it's own mirror image.

Diastereomers

Stereoisomers which contain more than one chiral centre and are not a mirror images of each other.

Enantiomers

Molecules that ARE mirror images of each other, but are not superimpossible upon each other.

Entgeggen (E)

When functional groups are on opposite sides of a molecule, can also be described as Trans.

Primary Carbon

A carbon which is only bonded to one other carbon.

Mesocompound

A molecule that contains a chiral centre but is achiral (not chiral) as that it has a plane of symmetry.

Structural Isomer

Molecules made up of the same components but with differnt connections.

Stereo Isomer

Molecules made up of the same components with the same connections but with different three dimensional configuration.

Trans

When functional groups are on different sides of a molecule, can also be described as Entgeggen.

Tertiary Carbon

A carbon bonded to three carbons, this is more stable and likely to undergo bonding under Markacovs rule

Zusammen (Z)

When functional groups are on the same side of a molecule, can also be described as Cis.

Cis

When functional groups are on the same side of a molecule, can also be described as Zusammen.

The molecule/molecular branch that already has more hydrogens is more likely to attract more hydrogens and the molecule or molecular branch that has more groups is more likely to attract more groups, due to the stability of the carbocation (normally a secondary or tertiary carbon).

Hybrid Orbitals

Orbitals formed from mixing together atomic orbitals, like the spx, which result from mixing s and p orbitals.

Lewis Acid

An electron pair acceptor, also known as an electrophile and a bronstead acid. An example of which would be Bromine.

Nucleophile

A molecule which is attracted to nucleases of other atoms, also known as a Lewis Base

Lewis Base

An electron pair donator, a molecule more likely to want to give away electrons, also known as a nucleophile and bronstead base. An example of which would be hydronium.

Conjugate Base

The base that results from the deprotonation (removal of H+ Ions) of an acid.

Conjugate acid

The acid thats results from the protonation (addition of H+ Ions) of a base.

Alkanes

A molecule containing only single bonded carbons and hydrogens. Also called hydrocarbons or saturated hydrocarbons as they contain the maximum possible number of hydrogens. Their molecular formula is CnH2n+2, so number of hydrogens equals number of carbons multiplied by two plus two.

Functional Group

A reactivity centre, the naming of organic molecules is based on which of these groups is present.

pKa value

A quantitative measure used to assess a molecule's acidity. It is dervied from the rate constant for the acids dissociation. Weak acids have values of between zero and nine, strong acids have values of less than zero. The values can be used to predict the directions of acid based reactions at equilibrium.

R

This letter is used as an abbreviation for Rest of the molecule and is commonly used as shorthand to imply a hydrogen atom or a hydrocarbon group. It is used when a generality is being demonstrated, or when the rest of the molecule is not very important in understanding what is being discussed.

Alkene

A molecule containing a carbon to carbon double bond. They can be arranged in rings although they generally like to be in big rings and can be transformed in to many different functional groups. Vitamin A (retinol) belongs to this group of molecules.

Ethylene

The simplest alkene, a gaseous hormone released when plants reach maturity signalling that it's time for fruit to start ripening. Polymerizes of this are used to produce polyethylene for making milk bottles and carrier bags.

Alkyne

Molecules which contain a carbon to carbon triple bond. Many of their reactions and properties are similar to those of alkenes although they are less common than alkenes in nature. They prefer to bond at 180 degree angles with the triple bond and the two R groups on either side in a straight line.

Aromatics (arenes)

Rings containing double bonds, they are significantly more stable and less reactive than other rings. Often used as a cheap solvent or starting material by organic chemists..These rings are found in morphine, auto exhausts, soot, and tobacco smoke.

Heteroatoms

This group of atoms includes important atoms such as halogen, oxygen and sulfur and are the components of the halide, alcohol, ether and thiol groups.

Halogens

The elements found in the 7A column of the periodic table, for example fluorine, chlorine, bromine and iodine.

Halides

Organic compounds that contain one or more halogens (such as fluorine, chlorine, bromine or iodine). They are commonly used for teflon coating as propellants and refrigerants. Seldom found in natural products. When they do occur naturally they tend to be toxins. Popular with organic chemists as they are thruways to other molecules.

Alcohol

A very common and important group of organic compounds consisting of the general formula R-OH. commonly found in natural products, for example table sugar.

Thiols

Foul smelling compounds of the general formula R-SH, the sulfur analogue of alcohol.These are responsible for the odours omitted by flatulence, garlic, sewage and rotten eggs. The amino acid cysteine, important in keratin in the human body.

Ethers

Molecules containing an oxygen sandwiched between two carbons, widely used as solvents in organic reactions. Historically it was used as an anaesthetic before theinvention of modern anaesthetics.

Carbonyl group

A carbon double bonded to oxygen C=O, not considered a functional group but a component in some of the most important functional groups including aldehydes, ketones, esters, amides and carboxylic acid. Most of the reactions in the body concern these groups.

Aldehydes

The simplest form of carbonyl compound, an double bonded oxygen flanked by one hydrogen and one R group, often written as R-CHO. It can be thought of as a carbonyl group at the end of organic molecule. The simplest form of this compound is formaldehyde an example of alarge member is Retinal. Retinal is one of the pigments responsible for trapping light in the eyes of humans.

Ketones

A carbonyl group sandwiched between two carbons, this can also be thought of as a carbonyl group somewhere in the middle of a molecule. An example of this is acetone (see diagram)

Carboxylic acids

A functional group made up of a carbonyl group attached to an OH group. These are contained in every amino acid of the body as do all the fatty acids. Members of this groups generally end with -oic acid, like ethanoic acid, more commonly known as acetic acid.

Esters

A carboxylic acid with the hydrogen sniped off and an R group glued in it's place. Generally sweet smelling, many are contained in the sweet smell of fruits.

Amide

Close relatives of Esters, but with a nitrogen rather than an oxygen next to the carbonyl group. Often found in nature, amide bonds hold all of our proteins together (the protein amide bond is known as a peptide bond). Penicillin contains two amide groups.

Amine

Nitrogen atoms that take the place of a carbon atom in an alkane. Not known for their pleasantness the smell of putrified flesh is caused by these. These compounds are often abused and substance such as cocaine, amphetamine and morphine contain them. In fact they are essential to the activity of most illegal drugs.

Nitriles

Compounds that contain a carbon triply bonded to a nitrogen, useful in organic synthesis. These can be converted in to carboxylic acids and amines by well known procedures.

Optically active

The term which describes a compound (such as a pure solution of a single enantiomer) which has the ability to rotate plane polarised light.

Racemic mixtures

This is a 50:50 mixture of two enantiomers which does not rotate plane-polarized light. These mixtures are very difficult to seperate.

Isomerism

Molecules with the same molecular formula but different structures.

Conformation

The different ways atoms can stretch or bend.

Stereochemistry

The orientation of atoms in three dimensional space.

Substituent

A fragment that comes off the parent group.

Eclipsed Conformation

This results when the bonds from the front carbon and the bonds from the back carbon align (in a Newmans projection) and the angle between the bonds (known as a dihedral angle) is zero degrees. This conformation is the higher energy conformation.

Staggered Conformation

This conformation results when the bonds from the front carbon and the bonds from the back carbon have a dihedral angle of 60. In this conformation the bonds are as far apart from each other as possible and this is the conformation with the lowest energy.

Torsional Strain

Electron - electron repulsion causes this strain when the dihedral angles are close to that of the eclipsed conformation (and therefor less stable). Staggered conformations have larger gaps between the electrons and there for less repulsion making them more stable.

Anti conformation

A type of staggered conformation in which the two big groups are opposite each other (180 degrees apart) in a newman projection.

Alkyl Halide

Organic compound in which halogen atoms (Br, Cl, Fl, I) have been substituted for hydrogen atoms in an alkane.

Hydrohalic Acids (Hydrogen Halide)

Acids resulting from the chemical reaction of hydrogen with one of the halogen elements (fluorine, chlorine, bromine, and iodine), which are found in Group 7 (VII, VIIA) of the periodic table. Astatine is not included in the list because it is very rare, unstable and not found as the acid in substantial quantities. Hydrogen halides can be abbreviated as HX where H represents a hydrogen atom and X represents a halogen (fluorine, chlorine, bromine or iodine).

Alkyl Group

A functional group of an organic chemical that contains only carbon and hydrogen atoms, which are arranged in a chain. They have general formula CnH2n+1Examples include methyl CH3 (derived from methane) and butyl C2H5 (derived from butane). They are not found on their own but are found attached to other hydrocarbons.

Akylation

A refining process in which an alkyl group replaces a hydrogen atom in an organic compound. An alkylate is the product of an alkylation process. This process is used in petroleum refining to produce high-octane gasoline, a process using hydrofluoric acid (HF) as a catalyst.

Hyperconjugation

The weak overlap which occurs between the empty p orbital on a carbocation and the sigma bond of an adjacent alkyl C-H bond. The more alkly groups present on a carbocation centre the more the positive charge is shared and the more stable the carbocation is. This type of carbo cation is favoured in Markovnakovs rule.

Organic Chemistry Flashcards ionicons-v5-c

Organic Chemistry Flashcards