Organic Chemistry Flashcards
Acid and Bases: Lewis Acid:
e- acceptor. Has vacant orbitals or + polarized atoms
Acids and Bases: Lewis Base
e- donor. Has a lone pair of e-, are often anions
Acids and Bases: Brønsted-Lowry Acid:
Proton donor
Acids and Bases: Brønsted-Lowry Base
Proton acceptor
Acids and Bases: Amphoteric
Molecules
Can act as either acids or bases, depending on
reaction conditions.
Acids and Bases: Ka
Acid dissociation constant. A measure of acidity. It is
the equilibrium constant corresponding to the
dissociation of an acid, HA, into a proton and its
conjugate base.
Acids and Bases : pKa
An indicator of acid strength. pKa decreases down the
periodic table and increases with EN.
p𝐾a = −log (𝐾a)
Acids and Bases: a-carbon
A carbon adjacent to a carbonyl.
Acids and Bases: a-hydrogen
Hydrogen connected to an a-carbon.
Redox Reactions: Oxidation Number
The charge an atom would have if all its bonds were
completely ionic.
Redox Reactions: Oxidation:
Raises oxidation state. Assisted by oxidizing agents.
REDOX Reactions: Oxidizing Agent:
Accepts electrons and is reduced in the process
Redox Reactions: Reduction
Lowers oxidation state. Assisted by reducing agents
Redox Reactions: Reducing Agent
Donates electrons and is oxidized in the process
Solvents: Polar Protic
Polar Protic solvents
Acetic Acid, H2O,
ROH, NH3
Sovents Polar Aprotic
Polar Aprotic solvents
DMF, DMSO,
Acetone, Ethyl Acetate
Nucleophiles:
“Nucleus-loving”. Contain lone pairs or p bonds. They have (arrow up)
EN
and often carry a NEG charge. Amino groups are
common organic nucleophiles
Nucleophilicity
A kinetic property. The nucleophile’s strength. Factors that
affect nucleophilicity include charge, EN, steric hindrance,
and the solvent
Electrophiles
“Electron-loving”. Contain a + charge or are positively
polarized. More positive compounds are more electrophilic
Leaving Group:
Molecular fragments that retain the electrons after
heterolysis. The best LG can stabilize additional charge
through resonance or induction. Weak bases make good LG
SN1 Reactions:
Unimolecular nucleophilic substitution. 2 steps. In the 1st
step, the LG leaves, forming a carbocation. In the 2nd step,
the nucleophile attacks the planar carbocation from either
side, leading to a racemic mixture of products.
Rate = 𝑘 [substrate]
SN2 Reactions
Bimolecular nucleophilic substitution. 1 concerted step. The
nucleophile attacks at the same time as the LG leaves. The
nucleophile must perform a backside attack, which leads to
inversion of stereochemistry. (R) and (S) is also changed if
the nucleophile and LG have the same priority level. SN2
prefers less-substituted carbons because steric hindrance
inhibits the nucleophile from accessing the electrophilic
substrate carbon.
Rate = 𝑘 [nucleophile] [substrate]
Alcohols:
Have the general form ROH and are named with the suffix –ol.
If they are NOT the highest priority, they are given the prefix
hydroxy
Alcohols can hydrogen bond, raising their boiling and melting
points
Phenols:
Benzene ring with –OH groups attached.
Phenols are more acidic than other alcohols because the
aromatic ring can delocalize the charge of the conjugate base
Describe the structure of a phenol ( (ortho)
Describe the structure of a phenol (meta)
Describe the structure of a phenol (para)
Reactions of Alcohols : Primary
Alcohols
Can be oxidized to aldehydes only by pyridinium
chlorochromate (PCC); they will be oxidized all the way to
carboxylic acids by any stronger oxidizing agents
Reactions of Alcohols : Secondary
Alcohols
Can be oxidized to ketones by any common oxidizing agent
Alcohols can be converted to make better leaving groups and the groups are
Mesylates
Tosylates
Mesylates:
Contain the functional group –SO3CH3
Tosylates
Contain the functional group –SO3C6H4CH3
Infrared Spectroscopy - IR range and Peaks N-H
Range 3300 peak Sharp
Infrared Spectroscopy - IR range and Peaks O-H
3000-3300 - Broad
Infrared Spectroscopy - IR range and Peaks C triple bond N
1900 – 2200 Medium
Infrared Spectroscopy - IR range and Peaks C=0
1750 Sharp
Infrared Spectroscopy - IR range and Peaks C=C
1600-1680 Weak
Solubility-Based Methods - Extraction:
Combines two immiscible liquids, one of which easily
dissolves the compound of interest.
Solubility-Based Methods - Extraction: Nonpolar Layer
Organic layer, dissolves nonpolar
compounds.
Solubility-Based Methods - Extraction: Polar Layer
Aqueous (water) layer. Dissolves
compounds with hydrogen bonding or polarity
Solubility-Based Methods — Wash
The reverse of an extraction. A small amount of
solvent that dissolves impurities is run over the
compound of interest.
Solubility-Based Methods (filtration)
Isolates a solid (residue) from a liquid (filtrate)
What are the two filtration methods
Gravity Filtration:
Vacuum Filtration
Solubility-Based Methods : Gravity Filtration
Use when the product of interest is
in the filtrate. Hot solvent is used to maintain
solubility.
Solubility-Based Methods : Vacuum Filtration
Used when the product of interest
is the solid. A vacuum is connected to the flask to pull
the solvent through more quickly.
Solubility-Based Methods : Recrystallization:
The product is dissolved in a minimum amount of hot
solvent. If the impurities are more soluble, the
crystals will reform while the flask cools, excluding the
impurities
Chromatography
Separates two or more molecules from a mixture. Includes liquid
chromatography, gas chromatography, size-exclusion chromatography,
ion-exchange chromatography, affinity chromatography, and thin-layer
chromatography
Distillation
Separates liquids according to differences in their boiling
points. The liquid with the lowest BP vaporizes first and is
collected as the distillate
Simple
Distillation
Can be used if the boiling points are under 150°C and are at
least 25°C apart
Vacuum
Distillation
Should be used if the boiling points are over 150°C to
prevent degradation of the product. The vacuum lowers
the air pressure, which decreases the temp the liquid must
reach in order to boil
Fractional
Distillation
Should be used if the boiling points are less than 25°C apart
because it allows more refined separation of liquids by BP
