1: the basics Flashcards
abbreviations for 1-6
1: meth
2: eth
3: prop
4: but
5: pent
6: hex
abbrevs 7-12:
7: hep
8: oct
9: non
10: dec
11: undec
12: dodec
nomenclature steps
- longest continuous c chain = base name
- number c’s - 1st sub lowest
- name sub’s using C# and prefix di-, etc
- list sub’s ALPHA – ignore numberical prefix and hyphenated prefixes BUT NOT iso or cyclo
- more than one way to number chain? choose sub on lower C by alpha
- multiple ways to come up with longest chain? pick one with most substituents
when is the only time you use a numerical prefix to list alphabetically?
when a smaller chain is a substituent off the main chain — put it in parentheses, C1 of the sub chain is the C attached to the main chain, (2,3,4-trimethylpentyl) – in big name, you would use this as substituent and use tri for alpha
IUPAC of isobutyl
2-methylpropyl
IUPAC tertbutyl
dimethylethyl
ether naming rules, common and IUPAC
common: name chains on either side of O, alphabetize them, add ether (ethyl methyl ether)
IUPAC: find longest chain and name ether as substituent (methoxyethane)
what does n-(prop/but/etc)yl mean?
straight chain alkane (vs iso or tert, etc)
amine
NH2, part of longest chain, butan-1-amine
aldehydes
-al, dont need to number because at end of chain (chain - C double bond O and C also to H)
carboxylic acid
-oic acid, dont need to number because it is at end with an OH (H in aldehyde; O- in -ate ion)
ester
C1 = carbonyl C, single bond to other O
-longest chain is named at carboxylate ion (-ate) adn otherside of O comes 1st, ethyl butanoate
amide
suffix: amide, C1 = carbonyl C, other side is NR2/NHR/NH2; ex- 3,N,N-trimethyl butyl if 5C chain with CH3 attached to the amide N and also to C3
priority groups
- carboxylic acids/derivs
- aldehydes
- ketones
- alcohols
- amine
- alkynes/ene
aromatics: benzene rings with attachments
- toluene: CH3
- benzoic acid: COOH
- benzaldehyde: COH
- phenol: OH
- anilene: NH2
- anisole: OCH3
- styrene: ring-CH-pi bond-CHH
- xylene: 2 CH3’s
ortho, meta, para
ortho: next door
meta: 2 over
para: across
electron domains (NOT MOLEC GEO) - includes bonding domain and lone pair
2: sp, 180, linear
3: sp2, 120, trigonal planar
4: sp3, 109.5, tetrahedral
effect of lone pairs on molec geo
repulsion – bond angle lower than expected
sigma vs pi
sigma: end to end overlap of orbitals, the hybrid orbital overlaps
pi: sideways overlap from p orbitals
intermolecular forces:
- H bond
- dipole dipole
H-bond: super strong dip-dip; F-H/O-H/N-H required if pure BUT if in a protic solvent, only F, N, O needed (formaledyde, for example)
dip-dip: interaction between molecules with permanent dipole moment; larger dipole moment = larger force; only POLAR molecule
London: all molecules, larger = bigger, weak interaction due to transient dipole
effects of IM on BP/MP/VP
higher IM force = higher BP and MP, lower MP
effects of branching on MP and BP
more branching = lower BP bc less SA; higher MP bc locks into crystal lattice easier
solubility ground rule
like dissolves like
nucleophile
electrophile
nuc: e- donor; lone pairs e-; pi e-; (-) charge is better
electrophile: e- pair acceptor, (+) charge
strength of nucleophiles, aprotic and protic
all of them get stronger as electronegativity decreases (because easier to donate e- if lower electronegativity)
aprotic: stronger to left and up
protic: H-bonds interact with the donor e- and reduce strength, but stabilizing effect is lower on bigger atoms, so strength increases with size in protic solvents (best is to the left and down)
reaction intermediates - carbocation stability
3 > 2 > 1 > Me
radical stability
3 > 2 > 1 > Me
carbanion stability
me > 1 > 2 > 3
resonance:
delocalization of e-, in more than one bonding position at once
major resonance structure: most stable, more pi bonds (more bonding e- = lower energy), more (-) on more eneg atoms
allylic carbon
C one away from pi, pi e- can move to it
induction
makes carbocation less stable because it pulls (-) from (+), so a C-cat with 3 F’s at end is less stable than H’s
makes carbanion more stable because it pulls (-) from (-), so C-anion with 3 F’s more stable
eneg highest to lowest
F O N Cl Br I — C —- H
oxidation and reduction
oxidation: loss of e-, more bonds to eneg atom (more C-O), fewer bonds to electropositive atom (fewer C-H)
reduction: gain e-, more bonds to epositive atoms (C-H), fewer to eneg (C-O)
formula for saturated hydrocarbon
CnH(2n+2)
1 degree unsaturation = every 2H’s missing from CnH2n+2
unsaturation - how many degrees?
every 2 H’s missing from CnH2n+2 is one degree unsaturation; pi bond or ring
how do you solve a saturation problem given just the structure
count C’s; determine # H’s there should be for saturated molecule; count pi and rings to determine degree unsaturation; multiply that by 2 and subtract from the saturated number of H’s to determine how many H’s there actually are
rules of saturation: O, N, X (halogen)
O: no change
X: act as H
N: add 1 more to # of H’s needed for sat#
acid vs base, BL defs
acid = H+ donor
base = H+ acceptor
base ranking overview
stronger acid = weaker conjugate base
a more stable conjugate base means what?
stronger acid
lower pKa means what
stronger acid (negative is strongest)
5 base ranking rules – CARDIO
C: charge
A: atom
R: resonance
D-I: Dipole induction
O: orbitals
effect of C on acid/base
C = charge; (-) is stronger base, (+) is stronger acid
effect of A on acid/base
A: atom
1. size - larger means more stable, so weaker base. smaller is stronger base.
- electronegativity: more eneg is weaker because it stabilizes the charge
**stonger up (smaller) and to the left (less eneg)
effect of R on acid/base
R: resonance – greater number and quality of resonance structures means more stable, means weaker base
effect of D-I on acid/base
D-I: dipole induction; eneg atoms stabilize basic atom and make weaker base
***proximity and strength of electronegative atoms
effect of O on acid/base
O: orbitals – compare different carbons, sp>sp2>sp3 stability declines as you go from sp to sp3
electrons closer to nucleus (s) - lower energy, higher stability
sp: 50% s, 50% p
sp2: 33% s, 67% p
sp3: 25-75
how do you rank acids?
rank conjugate bases, weaker conjugate base means stronger acid
exceptions to acid ranking — there are 2
- carboxylic acid is stronger than ammonia because of the resonance in the carboxylate (conj base of carb. acid)
- carboxylic acid is stronger acid than phenol (2 resonance structures of carboxylate – between 2 O’s; stronger than 4 resonance structures of phenol between 3 C’s and 1 O)
