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
