Dr. Collins Organic Chemistry 1
Single Bond
1 sigma bond
form: formaldehyde
H₂CO
monounsaturated
one double bond
Elements of Unsaturation
Compounds with double bonds, triple bonds, or rings have less than 2n+2 hydrogens Each element of unsaturation is 2 H's less than the maximum 2n+2 (i.e. 2H = 1 element of unsaturation) Double Bond = 1 element of unsaturation Triple Bond = 2 elements of unsaturation Ring = 1 element of unsaturation C₆H₁₀ 2(6)+2=14 → 14-10=4 → 2 elements of unsaturation → 2 DB, 1 TB, or 1 DB + 1 ring
Cause of Combustion
Compounds with low BP (hydrocarbons/non-polar organic compounds) have high vapor or at gases at room temperature, making them flammable/explosive/combustible
Hybridization of Two-Dimensional (Flat) Molecules
Contain only sp and/or sp² atoms (other than H)
Elements of Unsaturation for Formulas containing Halogens
Halogens (F, Cl, Br, I) form single bonds like H; replace halogens with H and calculate elements of unsaturation C₂H₂Cl₄ = C₂H₆ 2(2)+2=6 → no unsaturations
Sigma Bond
Head-on overlap of atomic (s, p) or hybrid (sp, sp², sp³) orbitals
Electrophile
Lewis Acid (electron acceptor)
Nucleophile
Lewis Base (electron donor with formation of a bond)
Solubility
Like dissolves like
aldehyde
R- CHO oxygen and carbon are double bond
ester
R- CO₂- R'
carboxylic acid
R- CO₂H or R- COOH
Electronic Geometry
Shape of molecule described by the bonded and unshared electrons
Molecular Geometry
Shape of molecule without lone pairs of electron
Pi Bond
Side-to-Side overlap of p orbitals
Conjugate Base Stability
Strong acids ionize readily; the stronger the acid, the more stable (less reactive) the conjugate base Conjugate base stability can be due to: 1. higher EN of atom in conjugate base 2. larger size 3. resonance stabilization
radical
a species with an unpaired electron
two dimensional sharp
benzene
imine
carbon and nitrogen double bond
azide
liner 180 degree
diatomic
molecules that exist as two atoms covalently bonded together
Polyunsaturated
more than one double bond
Saturated
no double bonds higher melting point than unsaturated fatty acid
the rutherford Gold Foil
nuclear structure of atom
Unsaturated fatty acids
one or more double bond
ketogenesis
produce ketone in bodies that take place in the liver under fasting condition. Fatty acids to B oxidization --> Acetyl-CoA--> Ketone
Alkyne
triple carbon bond
addition reaction
double bond become single bond
Alkene
double carbon bond
DNA
form by hydrogen bond
zwitterion
formerly called a dipolar ion, is a neutral molecule with both positive and negative electrical charges
longer hydrocarobon chain
higher melting point
Bonding Characteristics of Carbon
Carbon always obeys octet rule in neutral molecules
hydration
OH came from water
Double Bond
1 sigma + 1 pi bond Each atom involved has a sp² orbital (forms sigma bond) and a p orbital (forms pi bond)
Triple Bond
1 sigma + 2 pi bonds Each atom involved has a sp orbital (forms sigma bond) and 2 p orbitals (forms pi bonds)
amides
1° R- C -NH2 // O 2° R- C -NH -R' / / O 3° R - C- N -R -R'
amines
1° R-NH₂ 2° R-NH 3° R-N-R' - R''
Dehydration most easily
3°>2°>1°
Hydrogen Bonds
Attraction between positive H and negative O, N, or F Molecules with -OH or -NH groups (or the molecule HF) can hydrogen bond
Boiling Point Trends
BP increases with number of C (increasing MW or molar mass) A molecule with a more polar group (or more EN atom) will have a higher BP Groups that can hydrogen bond will increase the BP the most
Elimination Reaction
Base accepts proton Acid donates proton
aniline
BenzeneR-NH2
Acid
Bronsted-Lowry Acid (proton donor)
Base
Bronsted-Lowry Base (proton acceptor)
General Formula for Alkane
C(n)H(2n+2)
saturated formular CnH2nO2
C16H32O2 saturated fatty acid
SN2
CH₃ CH-CH₂ Cl (secondary degree Alkyl Halide)
SN1
CH₃ CH₂ F Alkyl Halide (1 degree)
SN3
CH₃ CH₃ - C- CH₃ - Tertiary
Halide
CH₃ I
fastest reaction
CH₃X > 1 degree > 2 degree >>> 3 degree
esterification
Carboxylic acid + alcohol → Ester + Water
multiple proportions
Co/C02 diiference in O
loss 2 Hydrogen ethane
Ethene
ferrous
Fe²⁺
ferric
Fe³⁺
Influence of Shape/Polarity on Physical Properties
More symmetrical/less polar molecules have lower BP More symmetrical molecules pack more tightly together, requiring more energy to melt → higher MP trans-alkenes have lower BP and higher MP than cis-alkenes
Bonding Characteristics of Nitrogen and Oxygen
N and O always obey octet rule and complete their octets with lone pairs of electrons
Substitution Reaction
Nucleophile donates electron and forms bond Electrophile accepts electron
Bond Length
The more s character an orbital has, the shorter the bond H-H < triple bond < double bond < single bond s-s sp-sp sp²-sp² sp³-sp³
Hydration reaction
reactant no water but product has water
Neutralization reaction
reaction between an acid and base to form salt and water
Dehydration
reaction which net overall elimination of water
metathesis reaction
reactions in which ions are exchanged
dehydration reaction
single bond to double bond
alkane
single carbon bond
Geometry of sp Hybridization
sp linear (180°)
Geometry of sp² Hybridization
sp² trigonal planar (120°)
Geometry of sp³ Hybridization
sp³ tetrahedral (109.5°)
best leaving group Sn2 reaction
weak base
