Chem 202 all units

ketone

R-C=O-R

Acid Chloride

R-C=O-Cl

acid anhydride

R-C(=O)-O-C(=O)-R

carboxylic acid

R-COOH

Amide

-CONH2, -CONHR, -CONR2

Ester

RCOOR

Nucleophilic Addition

a reaction in which an electrophilic π bond reacts with a nucleophile, breaking the π bond and forming 2 new σ bonds.

Ammonia

NH3

Ester Hydrolysis

ester reacts with H2O to produce a carboxylic acid and an alcohol

Fischer esterification

The formation of an ester from a carboxylic acid and an alcohol in acidic conditions

pka of hydronium or ROH2+ (ie.

protonated alcohol)

<0

pka of HCl, HBr, HI

< -8

pKa of RCOOH (carboxylic acid)

5

pKa of ammonium ion, protonated

amines

9-11

pKa of pyridinium ion

5

pKa of phenol

10

pKa of ROH or H2O

15

pKa of NH3

38

pKa of CH3CH3 (or RCH3)

50

pKa of CH2CH2

44

pKa of HCCH

25

alkyl group

An alkane with a hydrogen atom removed

carbonyl compound

any compound that contains a carbonyl group C=O

kinetic product

Faster due to lower activation energy, typically at low temperatures. lower activation energy but higher Gibb's free energy

thermodynamic product

more stable (lower energy) and favored at high temperatures. The product has higher activation energy but lower Gibb's free energy

acid-catalyzed reaction

uses a small amount of acid to speed up a process, with the acid regenerated in the end (e.g., hydration of alkenes)

acid-promoted reaction

requires a stoichiometric amount of acid that is consumed, not regenerated

base-promoted reaction

A base facilitates chemical bond breaking, commonly in ester hydrolysis (saponification) or amide hydrolysis. The base acts as a nucleophile, attacking carbonyl carbons, rather than just a catalyst, as it is consumed in the process.

carboxylate anion

conjugate base (RCO2-) of a carboxylic acid, is produced by base-promoted reaction

Leaving Group (LG)

- atom or group of atoms which break away from the molecule

- accepts electrons from C-LG bond

Factors:

1. resonance (increases electron accommodation)

2. atomic radius (larger radius increases electron accommodation)

3. electronegativity (high EN increases electron accommodation)

4. inductive effects

5. formal charge

Excellent:

1. sulfonate ions

2. iodide ion

Moderate:

1. bromide ion

2. chloride ion

3. water

4. alcohols

Rare:

1. fluoride ion

2. amines

3. oxyanions

4. nitranions

Never:

1. alkyl group

phenol

Benzene ring with -OH

pyridinium ion

5.2/ring w/three double bonds and N-H

Alkyl Halide

An alkane in which one of the hydrogens has been replaced by a halogen.

Acetic Acid

CH3COOH

Alkane

a hydrocarbon containing only single covalent bonds

1 carbon

methane

2 carbon chain

Ethane

3 carbon chain

Propane

4 carbon chain

Butane

5 carbon chain

Pentane

6 carbon

Hexane

7 carbon chain

Heptane

8 carbon chain

Octane

9 carbon chain

Nonane

10 carbon chain

Decane

isopropyl

1-methylethyl

CH3CHCH3

First-order units

1/s or s^-1

second-order units

M^-1 s^-1

SN1 rate law

rate = k[alkyl halide]

SN2 rate law

rate = k[alkyl halide][nucleophile]

SN1 activation barrier

stability of C+ intermediate

SN2 activation barrier

accessibility of LUMO simga star

SN1 nucleophile

weak nucleophiles, usually neutral (H2O, ROH, RNH2)

SN2 nucleophile

strong nucleophile (usually charged) -OH,-OR, -NRH

SN1 LUMO for addition

Empty 2p on C+

SN2 LUMO for addition

empty sigma star

SN1 sterochemistry (if RX has an asymmetric carbon)

racemic mixture

SN2 sterochemistry (if RX has an asymmetric carbon)

inversion

asymmetric carbon

A carbon that is attached to four different atoms or groups of atoms.

racemic mixture

a mixture of equal amounts of two enantiomers

SN1 solvent preference

Faster in polar protic (usually the nucleophile)

SN2 solvent preference

Faster in polar aprotic

Polar protic

methanol (CH3OH)

ethanol (CH3CH2OH)

water (H2O)

ammonia (NH3)

polar aprotic

Polar but do not have hydrogens bonded to highly electronegative atoms (DMSO)

SN1 alkyl halide

3>>>2>1

SN2 alkyl halide

1>>>2>3

DMSO (dimethyl sulfoxide)

polar aprotic

RX

electrophile

Primary Alkyl Halide (1)

An alkyl halide in which the carbon atom bonded to the halogen is also bonded to 1 other carbon atom.

Secondary Alkyl Halide (2)

The carbon to which the halogen is bonded is attached to two other carbons

Tertiary Alkyl Halide (3)

The carbon to which the halogen is bonded is attached to three other carbons

Zeroth Order Rate Law

Rate = k (change in concentration has no effect on the rate)

First Order Rate Law

Rate = k[A]

Second Order Rate Law

Rate=k[A]^2

Zeroth order integrated rate law

[A]t = [A]0 - kt

First Order Integrated rate law

ln[A] = - kt + ln[A]0

second order integrated rate law

1/[A]t = kt + 1/[A]0

zeroth order units

m/s

Rates

Rates of appearance or disappearance. Dependent on stoichiometric relationships (the balanced equation)

Rate Law

k= rate constant, units vary depending on x and y. x and y can only be determined from experiment.

1. The magnitude of k indicates how fast or slow the reaction is.

2. Rate law is dependent on concentrations, not stoichiometry

3. Must be determined experimentally

4. Rate constant k is not the same as the rate of the reaction

Arrhenius equation

k=Ae^(-Ea/RT) or ln(k2/k1)=-Ea/R((1/T2)-(1/T1))

Half-life (t1/2)

The time it takes for the amount of drug to fall to half of its value; this is a constant in first-order kinetics. This is independent of initial concentrations.

Steps for a ester hydrolysis

PADPED

Kinetics

"How fast?"

- Collisons

- mechinsim/pathway

- catalysis

- path dependent

Thermodynamics

"How far"

- Equilibrium (delta G naut = -RTlnK)

- Path independent

Free Energy (delta G)

Spontaneity

Enthalpy (delta H)

The property that quantifies thermal energy transfer in or out of a system at constant pressure

Entropy

How is energy spread out in a system? Higher entropy correlates with more possible microstates, representing greater matter dispersal

1st Law of Thermodynamics

Energy cannot be created or destroyed, only exchanged

2nd Law of Thermodynamics

The entropy of the Universe increases in all spontaneous processes.

Gibbs Free Energy Equation

ΔG = ΔH - TΔS

hydrophobic effect

The observed tendency of nonpolar substances to aggregate in aqueous solution and exclude water molecules. This increases the water entropy as they no longer have to make a rigid structure around non-polar substances.

Le Chatelier Equation

Delta G= RTln(Q/K)

Lewis Acid

A compound that accepts an electron pair

Lewis Base

A compound that donates an electron pair

Bronsted-Lowry acid

A compound that donates a proton (H+) in a reaction

Bronsted-Lowry base

A compound that accepts a proton (H+) in a reaction

Arrhenius Acid

A compound that, when dissolved in water, increases the hydronium ion concentration

Arrhenius Base

A compound that, when dissolved in water, the hydroxide ion concentration increases

Lewis acid-base adduct

A compound that contains a coordinate covalent bond formed between a Lewis acid and a Lewis base.