Chapter 6: ROH Flashcards
functional group definition
structural unit responsible for characteristics, physical and chemical properties under conditions
what are the 2 different naming conventions in IUPAC
functional class substitutive
what IUPAC naming class is preffered
substitutive
main difference between functional class and substitutive names
functional - alkyl followed by "alcohol" substitutive - start with longest C chain that has the OH group number closest to OH replace -ane with -ol substituents and location BFORE parent
where is OH assumed to be attached in cyclic alcohols
C-1
does alcohol or a halogen have higher priority
OH has higher priority than halo
how is the C-O bond made in alcohols
- overlap of sp3 orbital on carbon
- overlaps with one sp3 on oxygen
- oxygen is left with 2 nonbonding e- pairs
how are bonds made in alkyl halides
-halogen is connected to the carbon with a SIGMA bond
carbon-halogen bond distances trend
C-F < C-Cl < C-Br < C-I
more electronegetive halogen = smaller bond distance
what type of bonds do alkyl halides and alcohols have
polar bonds, and may be polar molecules
dipole-dipole attractive forces
molecules with permanent dipoles have a stronger dipole-dipole intermolecular interaction than alkanes
why does flouroethane, for example, have a higher boiling point than propane
because its dipole-dipole forces are stronger (flourine is very electronegative) and therefore boiling point is higher
what is different about ethanol and its boiling point
ethanols boiling point is so high that dipole-dipole interactions are not enough to explain it
explain bonding in alcohols
alcohols have hydrogen bonding (dipole-dipole)
partially positive proton of one -OH group interacts with the partially negative oxygen of a second ethanol
hydrogen bond acceptor and donor in alcohol bonding
oxygen = hydrogen bond acceptor
OH hydrogen = hydrogen bond donor
what are the onlu elements involved in hydrogen bonding in organic compounds
oxygen
nitrogen
NO
what are alcohols and their hydrogen bonds strong enough to do
impose structural order
methyl
CH3
ethyl
CH3CH2
propyl
CH3CH2CH2
pentyl
CH3(CH2)3CH2
hexyl
CH3(CH2)4CH2
iodine and polarization
iodine is highly polarizable
why is iodine highly polarizable
because the valence electrons are far from the nucleus
induced dipole-induced dipole forces
connection between halogens, dipoles and boiling point
- increase the number of halogens (Cl, Br, I)
- increases the dipoles
- increases boiling point
flourine and polarization
flourine has very low polarizability, and boiling points do not increase as you increase the amount of flourine
solubility of alkyl halides
insoluble in water
solubility of alcohols in water
is directly related to the size of the alkyl group that the OH is attached to (the more, the less soluble)
alcohols that are totally miscible in water
methyl, ethyl, n-propyl, and isopropyl
what is the only amount of octanol that dissolves in water
1 mL 1-octonol in 2000 mL water
densities compared to water
less dense than h2O = alkyl flourides and chlorides
more dense than water = alkyl bromides and iodides, CH2Cl2
halogenation and density
increasing halogenation increases density
what are the 3 main steps in radical mechanisms
- chain initiation
- chain propagation
- chain termination
what type of arrow do you use in radical mechanisms
fish-hook arrows