CHEM 40A Review

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alkanes vs alkenes vs alkynes

hydrocarbons with only

a- single bonds

e- double bonds

y- triple bonds

straight chain alkanes (names)

methane CH₄

ethane CH₃CH₃

butane

propane

pentane

hexane

heptane

octane

cycloalkanes

alkanes with ring structures (ie cyclohexane)

arenes (aka aromatic groups)

cyclic alkanes with alternating single and double bonds

(ie cyclohexane with alternating single and double bonds)

follows the 4n + 2pi rule & is conjugated

alcohol

OH group

amines

NH₂

ammonium compounds

NH₄+

alkyl halides

alkane in which one of its H has been replaced by a halogen

ethers

O attached to two C chains

esters

C double bonded with an O and single bonded with another O that is attached to an alkyl group

RCOOR

ketone

C double bonded to O and also 2 single bonds to 2 C’s

aldehyde

C double bonded to O and single bonded to H

carboxylic acid

C double bonded to O and single bonded to OH

COOH

amides

C doubled bonded to O and single bonded to amine group (NH2)

thiols

SH

(like alcohols but with S instead of O)

sulfides

S

disulfide

SS

phenyl

has benzene as a substituent

phenol

hydroxyl group directly attached to aromatic group

imine (aka Schiff base)

C doubled bonded to N

thioester

like an ester but single bonded to S (instead of O) that is attached to an alkyl group

acyl phosphate

C double bonded to O and single bonded to an O that is part of a phosphate group

acid chloride

C double bonded to O and single bonded to Cl

phosphate ester

phosphate diester

constitutional isomers def

same MF but different connectivity of atoms

naming: halides

-o

naming: OH

hydroxy-

naming: ketone

no e & -one

naming: aldehyde

-al

naming: carboxylic acids

-oic acid

naming: deprotonated carboxylic acid

-oate

naming: amide

-amide

how to identify

• lipids

• carbohydrates

• amino acids

• nucleic acids

• lipids (long hydrocarbon chains with phosphate group)

• carbs (C with H2O)

• amino acids (H, NH3, COOH group with side chain)

• nucleic acids (rings/bases with lines b/w connecting them)

sigma bonds have AOs overlapping - the internuclear axis

pi bonds have AOs overlapping - the internuclear axis

sigma (along)

pi (outside)

why are pi bonds weaker than sigma bonds

areas of overlap in pi bonds are not as extensive

they have less overlap between atoms (b/c is outside internuclear axis)

how to determine which is major or minor resonance contributor in non-equivalent resonance structures?

minor: not full octet

if both have full octet, then look at which atom has the negative FC, whichever atom is more electronegative is the major resonance contributor (other is minor)

solubility in water

has OH group

more soluble = less carbons

nonpolar is poorly soluble

higher boiling point = to

larger compounds

IMF and dipole-dipole interactions strengths

torsional strain def & steric strain

torsional - e^- repulsion between bonds on adjacent atoms (close)

steric - close and between large groups

staggered anti vs gauche

anti- largest group on front and back C’s that are 180 degrees apart

gauche - largest groups on front and back C’s are 60 degrees apart and are adjacent

alkyl groups list

me - methyl CH₃

Et - ethyl CH₂CH₃

pr - propyl CH₂CH₂CH₃

Bu - butyl CH₂CH₂CH₂CH₃

iPr - isopropyl CH(CH₃)₂

t-Bu - tert-butyl C(CH₃)₃

rotational isomers def

interchangeable when rotate around single bonds

stereoisomers def

can only interconvert by breaking covalent bonds

more stable when larger/bulkier group is -

equatorial

what 2 conf. have steric hindrance

eclipsed when two large are adjacent

staggered gauche