Final Flashcards
1
Q
chpt 1
HONC
A
Hydrogen 1
Oxygen 2
Nitrogen 3
Carbon 4
number of bonds to be neutral
2
Q
chpt 1
What molecules perform hydrogen bonding?
A
NOF
3
Q
chpt 1
Constructive interference
A
produces a bonding MO + larger wave amplitude
waves have effective overlap
4
Q
chpt 1
Destructive interference
A
creates an anti bonding MO, or a node
waves do not have overlap
5
Q
chpt 1
Orbitals are — in MO theory
A
conserved, the number you start with is the number you will end with
6
Q
chpt 1
HOMO
A
highest energy occupied molecular orbital
7
Q
chpt. 1
LUMO
A
lowest energy unoccupied molecular orbital
8
Q
chpt 1
How many unhyridized p orbitals are there on an sp3 hybridized molecule?
A
0, 1 S orbital with 3 p orbitals
9
Q
chpt 1
how many orbitals are formed in an sp2 hybridized molecule
A
3 orbitals
one unhybiridzed p orbital
10
Q
chpt 1
what kind of orbitals overlap to form sigma bonds?
A
hybridized orbitals
11
Q
chpt 1
what kind of bonds overlap to form pi bonds?
A
unhybridized
12
Q
chpt 2
if a carbon has a - charge what is attatched to it?
A
three bonds and a lone pair
sp3 hybridized
13
Q
chpt 2
if a carbon has a + charge what is attatched to it?
A
three bonds and no electrons
sp2 hybridized
14
Q
chpt 2
localized electrons
A
e- that do not participate in resonance, if they cannot participate they are localized
15
Q
chpt 2
delocalized electrons
A
e- that can participate in resonance
16
Q
chpt 2
True or false? if you have a molecule that has lone pairs + a pi bond both will participate in resonance
A
false, the pi bond will participate, not the lone pairs
17
Q
chpt. 2
How do you determine the most significant resonance structure?
A
- one with no charge will be the most significant
- if there are charges, the one with the fewest charges is most significant
- the structure with a negative charge on the most electronegative atom is most significant
stability = significance
18
Q
chpt 3
Bronsted Lowry Acid
A
proton donor
19
Q
chpt 3
Bronsted Lowry base
A
proton acceptor
20
Q
chpt 3
acids will not lose a proton without a — present
A
base
21
Q
chpt 3
explain the proton transfer mechanism
A
two arrows, one arrow from the atom to be protonated to the hydrogen and one arrow from the bond connecting the hydrogen to the connecting molecule
22
Q
chpt 3
curved arrows start at places of — —
A
electron density
23
Q
chpt 3
the — the pka value the stronger the acid
A
lower
24
Q
chpt 3
strong acids create — bases
A
weak
25
# chpt 3
CARIO
Charge
Atom
Resonance
Induction
Ortbials
| weak is winner!
26
# chpt 3
explain charge in CARIO
the neutral atom will be more stable than a charged atom
| bases will likely be negative or neutral
27
# chpt 3
Explain Atom in CARIO
a more electronegative atom with a charge will stabilize better
28
# chpt 3
In the choice between S- and O- in CARIO which one would you choose?
you would choose S because if atoms are in the same colum the larger one is more stable
| same row = electronegativity
29
# chpt 3
explain resonace in CARIO
a charged atom stabilized by resonace will be more stable than one without resonance
| delocalization stabilizes
30
# chpt 3
Explain induction in CARIO
more electronegative atoms (like halogens) will stabilize a negative charge, the more electronegative atoms the better
| the closer it is the better
31
# chpt 3
explain Orbitals in CARIO
the more s character the better
sp>sp2>sp3
32
# chpt 3
Which is the more stable base? NH2 or terminal alkyne?
this is an exception! a terminal alkyene is more stable than an amine
33
# chpt 3
Lewis Acid
electron pair acceptor
34
# chpt 3
Lewis base
electron pair donator
35
# chpt. 4
Newman Projection
used to view a front and back carbon of a molecule
36
# chpt. 4
staggard conformation
lower E, angles between groups are equal
37
# chpt. 4
eclipsed conformation
high E, groups are close together likely creating strain
38
# chpt. 4
Torsional strain
twisted, only occurs with ecplised conformations
39
# chpt 4
steric strain
can occur in staggard and ecplised conformations where two groups that are not hydrogens interact
40
# chpt 4
gauche conformation
staggard conformation with steric strain
41
# chpt 4
what is the most stable conformation of cyclohexane?
chair conformation, no strain
42
# chpt 4
every cyclohexane can have a max of -- chair conformations
two
43
# chpt. 4
True or false? after a ring flip the substiuents direction and position change
false, positon changes but not direction
| if its up then its up if its down then its down
44
# chpt 4
the most stable conformation will be one with all equitorial positions or ------
with the largest groups in equitorial positions
45
# chpt. 5
Constiutional Isomers
same formula, different connectivity
46
# chpt 5
stereoisomers
same formula, same connectivity, different spatial arrangments
| different wedges and dashes
47
# chpt 5
what does it mean to be chiral?
to be non superimposable on your mirror image
| achrial= you can super impose
48
# chpt 5
chiral center
a carbon with four different groups attatched
49
# chpt 5
stereocenter
an atom where swapping two groups produces a stereoisomer of the atom
| often sp2 atoms attatched to double bonds
50
# chpt 5
enantiomer
the mirror image of a molecule
51
# chpt 5
if you see a molecule that has been flipped across a mirrored surface and the wedges and dashes have also been flipped what is its relationship to the original molecule?
It is an identical molecule, if you do both options it creates an identical molecule
52
# chpt 5
Steps to designating R and S
1, find the chiral center
2. assign priority 1-4 to the four groups
3. is the 1st group wedged forward? is the fourth group dashed back? If not you will count 1-3 and then switch your answer to the oppostie of what you got
53
# chpt 5
what does it mean to optically active?
to be able to rotate a plane of polarized light
54
# chpt 5
enantiomers will rotate light in equal but -----
opposite directions
55
# chpt 5
how do you assign E and Z?
1. assign priority to one of the two groups on either side of alkene
2. if the higher priority groups are on the same side = Z
3. if the higher priority groups are on the oppostie side = E
56
57
# chpt 5
any compound with a plane of symmetry will be ---
| -or no chiral center
Achiral
58
# chpt 5
How do you determine the number of **stereoisomers** in a molecule?
2^n where n= number of chiral centers
- subtract 1 if there is a plane of symmetry
- count two stereocenters on either side of a pi bond as 1
- draw out possible stereoisomers
59
# chpt 6
enthalpy
the change in heat from reactants to products in a reaction
60
# chpt 6
what is the favorable sign for H (enthalpy)?
a negative H sign = an exothermic reaction= favorable
a positive H sign= endothermic reaction = non favorable
61
# chpt 6
entropy
the amount of disorder in a system
62
# chpt 6
what is the favorable sign for entropy?
a positive entropy = favorbale
a negative entropy = non favorable
63
# chpt 6
what sign of gibbs free energy indicates a spontaneous reaction?
a negative G indicates a spontaneous reaciton
64
# chpt 6
exergonic
spontaneous, negative G, reactants are higher in E than products
65
# chpt 6
endergonic
non spon, positive g, products are higher in E than reactants
66
# chpt 6
Keq>1
products favored
67
# chpt 6
Keq < 1
reactants favored
68
# chpt 6
What are the four factors that affect the rate constant?
1. temperature
2. presence of a catalyst
3. energy of activation
4. steric orientation
69
# chpt 6
transition states
the peaks of energy diagrams, high energy and unstable, the number of them indicates the number of mechanistic steps
70
# chpt 6
intermediates
'in' the well, lower energy and more stable
71
# chpt 6
hammonds postulate
- in an endergonic reation the transition states will more closely resemble products
- in an exergonic reaction the transition states will more closely resemble the reactants
72
# chpt. 6
nucleophile
electron dense, often have a - charge or l.p.
| ex: halides, negatively charged bases, HS-
73
# chpt 6
electrophile
electron deficent, attacked by nucleophiles
| ex: carbocations, alkykl halide, carbonyl group
74
# chpt 9
alkyne
triple bond, one sigma two pi bonds, can react as nucleophiles in reactions
| sp, 180, linear geometry
75
# chpt. 9
terminal alykne
end of a chain with an acidic H
76
# chpt 9
internal alkyne
sandwhiched between two carbons, within the chain
77
# chpt. 9
what sort of bases are strong enough to deprotonate a terminal alkyne?
C-, H-, N-
| Not O-!
78
# true or false?
a reaction will react towards the weak acid weak base?
true! it moves away from the strong acid strong base
79
# chpt 7
substiutution reactions
loss of a leaving group + nucleophilic attack
| will not react with tertiary alpha or beta carbons
80
# chpt 7
elimination reactions
loss of a leaving group + proton transfer to form an alkene
| likely to react with a secondary or tertiary alpha carbon
81
# chpt 7
SN2 reaction
a bimolecular substiution (depends on the substrate and the nucleophile) reaction that favors unsubstitued substrate also concerted
| only reaction that doesn't want to be substitued
82
# chpt 7
Factors that affect nucleophilicity
1. charge
2. polarizability
3. size
83
# chpt 7
How does charge affect nucleophilicity?
a charged nucleophile is a stronger one
84
# chpt 7
how does size affect a nucleophile?
a small nucleophile is a stronger one
| ex: Br-, Cl-
85
# chpt 7
Polar protic solvent
Has hydrogen bonding, not favored for bimolecular reactions
| favored for unimolecular reactions
86
# chpt 7
polar aprotic solvent
solvent without hydrogen bonding, not favored by unimolecular reactions
| favored by bimolecular reactions
87
# chpt 7
Backside attack
During an SN2 reaction the nucleophile attacks opposite to the leaving group and inverts the carbon
88
# chpt 7
E2 reaction
bimolecular,loss of a leaving group + proton transfer to form an alkene
89
# chpt 7
are bimolecular reactions concerted or stepwise?
concerted
90
# chpt 7
what kind of base do you want for a E2 reaction?
strong base with a charge, no resonance and no induction
| you want the loser of CARIO
91
# chpt 7
explain the characterisitics of a stable alkene
- a trans alkene is more stable than a cis alkene
- mono< di< tri< tetra substiuted
92
# chpt 7
Regiochemistry
where the reaction is taking place
| zaitsev or hoffman? markovnikov? anti?
93
# chpt 7
Zatisev product
more substitued product
94
# chpt 7
Hoffman product
less substitued product
95
# chpt 7
examples of weak bases/ weak nucleophiles
H2O, MeOH, EtOH
96
# chpt 7
examples of strong nucleophiles (weak base)
Br-, Cl-, HS-
97
# chpt 7
Examples of strong base (weak nucleophile)
DBU, DBN, TBuOk
98
# chpt 7
examples of strong base strong nucleophile
MeO-, EtO-
99
# chpt 7
what position do the hydrogen and leaving group need to be in for E2 to happen
they need to be anti to each other, the leaving group also has to be axial if there is a ring
100
# chpt 7
Unimolecular reactions
| SN1 and E1
stepwise reactions that are only dependent on the substrate
101
# chpt 7
True or false? Both unimolecular and bimolecular reactions can have rearrangments
False! bimolecular are concerted so no charges fully form
102
# chpt 7
Unimolecular reactions favor a --- substrate
hinderd, heavily substitued
| a tertiary substrate indicates unimolecular
103
# chpt. 7
a --- reaction will produce both SN1 and E1 one will be --- favored than the other
unimolecular, more
| which is more favored depends on substrate
104
# chpt 5
Meso compound
two or more chiral centers and a plane of symmetry
| rotate single bonds to check for 'invisible symmetry'
105
# chpt 9
How are alkynes prepared?
By a double elimination reaction using excess base
106
# chpt 9
Does the first or second elimination in alkyne preparation require a strong base?
the second elimination requires a strong base to push the reaction to products
107
# chpt 9
Geminal Dihalide
both X are attatched to the same carbon
108
# chpt 9
vicinyl dihalide
the two X are attatched to adjacent carbons
109
# chpt 9
Why do we deprotonate to form the alkylide ion and then protonate it again?
to form more products/ push towards the products
110
# chpt 9
True or false? One equivalent of HX for hydrohalogenation of an alkyne can produce a geminal dihalide and an alkene with a X group?
false, it requires excess HX to form a geminal dihalide from an alkyne
111
# chpt 9
What alkyne reaction is teramolecular?
hydrohalogenation of alkynes
| R= k[alkyne][HX]^2
112
# chpt 9
Which alkyne reaction can produce ketones and aldehydes?
hydration of alkynes
- Acid catalyzed= ketone
- boration= aldehyde
113
# chpt 9
Hydration of alkynes: Acid cataylized
markovnikov addition of OH +H across an alkyne using an acid and HgSO4 as a cataylst
| creates an enol that converts into a ketone
114
# chpt 9
enol
an OH group is attatched to a C=C bond, it will likely be rapidly interconverting to another molecule
115
# chpt 9
tautomers
constiutuional isomers that interconvert between each other because of the migration of a proton
116
# chpt 9
Hydroboration Oxidation for alkynes
anti markovinikov addition of OH +H across an alkyne using a Boron molecule
- final product is an aldehyde
117
# chpt 9
Why is BH3 not often used for boration of alkynes?
Because a larger molecule is necesary to keep from adding to the enol twice
118
# chpt 9
alkylation of alkynes
addition of groups to an alkyne using a strong base to deprotonate a terminal alkyne
119
# chpt 9
If you want to do a double alkylation with acetylene what must you not do?
Add all the reagants in at once, this will not produce the products you want
120
# chpt 8
Additions reactions are favored at --- temperatures
low
| elimination is favored at high temp
121
# chpt 8
Hydrohalogenation: alkenes
- intermediate?
- rearrangment?
- regiochem?
- stereochem?
- reagants?
1. carbocation intermediate
2. yes can rearrange
3. markovnikov addition
4. if a chiral center is created R and S is observed
5. HX
122
# chpt 8
Acid catalyzed hydration: alkenes
- intermediate?
- rearrangment?
- regiochem?
- stereochem?
- reagants?
1. carbocation
2. yes
3. markovnikov addition
4. same as hydrohalogenation, if chrial center is formed R and S is observed
5. Dilute H2SO4 +H2O (concentrated favors reagants)
123
# chpt 8
Hydroboration oxidation: alkenes
- intermediate?
- rearrangement?
- regiochem?
- stereochem?
- reagants?
1. boron intermediate
2. no rearrangment
3. antimarkovnikov
4. syn addition
5. BH3, THF
124
# chpt 8
Oxymercuration Demercuration: alkenes
- intermediate?
- rearrange?
- regiochem?
- stereochem?
- reagants?
1. cylic
2. no
3. markovnikov
4. anti addition
5. Hg(OAc)2
125
# chpt 8
Catalytic Hydrogenation: alkenes
- Intermediate?
- rearrange?
- regiochem?
- stereochem?
- reagant?
1. spaceship
2. no
3. N/A (adding same thing)
4. syn addition
5. H2 + metal catalyst
126
# chpt 8
halogenation: alkenes
- intermediate?
- rearrange?
- regiochem?
- stereochem?
- reagant?
1. cylic
2. no
3. N/A (Adding same thing)
4. anti addition
5. Cl2 or Br2
127
# chpt 8
Halohydrin: alkene
- intermediate?
- rearrange?
- regiochem?
- stereochem?
- reagant?
1. cylic
2. no
3. OH on more substitued position
4. anti addition
5. Cl2 or Br2 and H2O
128
# chpt 8
syn- Dihydroxylation: alkenes
- intermediate?
- rearrange?
- regiochem?
- stereochem?
- reagant?
1. concerted reaction
2. no
3. N/A
4. syn addition
5. Osmate ester or Postassium permangante (cold)
129
# chpt 8
Anti dihydroxylatin: alkenes
- intermediate?
- rearrange?
- regiochem?
- stereochem?
- reagant?
1. cylic epoxide
2. no
3. N/A
4. anti addition
5. Peroxy acids (MCPBA)
130
# chpt 8
Ozonolysis: alkenes
- intermediate?
- rearrange?
- regiochem?
- stereochem?
- reagants?
1. N/A
2. no
3. N/A
4. N/A
5. O3
131
# chpt 8
Will concentrated or dilute acid favor the products?
a dilute acid will favor the products for an alkene addition reaction
132
# chpt 9
If the alkyne looks the same on both sides what kind of products can you expect?
A mix of products with the OH placed on either side of the alkyne
133
# chpt 9
Catalytic Hydrogenation: alkynes
using H2 + a metal cataylst or poisoned catalyst to get a alkane or the cis alkene
134
# chpt 9
What is lindlars catalyst?
a poisoned cataylst used to form the cis alkene from an alykne
135
# chpt 9
Dissolving metal reduction
Using Na + NH3 (l) to create the trans alkene from an alkyne
136
# chpt 9
Why is reduction of alkynes so synthetically useful?
Bc you can go from an alkyne to an alkene to a alkane
137
# chpr 9
What kind of product does excess X2 w/CCl4 and an alkyne yield?
A tetra halide alkane
| no excess will yield a dihalide alkane
138
# chpt 9
What kind of product does an alkyne treated with 1 eq of X2 yield?
a tetrasubtitued alkene where the halogens are placed vicinally
| anti and syn addition
139
# chpt 9
What kind of products will a terminal alkyne treated w/ O3 produce?
A carboxlyic acid + CO2
| terminal carbon becomes CO2
140
# chpt 9
What kind of products will an internal alkyne treated with O3 produce?
Two carboxylic acids
141
# chpt 10
Radicals
species with one lone electron present, can be very reactive and unstable
142
# chpt 10
What kind of bond cleavage forms radicals?
homolytic bond clevage
143
# chpt 10
How would you describe the geometry of radicals?
A flatter trigonal pyramidal bc it is inbetween a carbanion and a carbocation
144
# chpt 10
True or false? Radicals and carbocations follow the same rearrangement rules.
False, radicals will not rearrange
145
# CHpt 10
homolytic BDE decreases with increasing -----
radical stability
146
# chpt 10
How many fish hook arrows for the most popular resonance pattern of radicals?
three arrows for a radical allylic to a pi bond
147
# chpt 10
Homolytic cleavage
intitation step, creates radicals by treatment of heat, light or peroxy acids (ROOR)
148
# chpt 10
Addition to a pi bond
| radical reactions
formation of an alkane radical from an alkene, propogation step
| opposite of elimination
149
# chpt 10
Hydrogen abstraction
removing hydrogen from its R group to form a carbon radical, propogation step
150
# chpt 10
Halogen abstraction
removal of X from X2 to form a radical group, propogation step
| used in halogenation of an alkane
151
# chpt 10
Elimination
| for radical reactions
X group is removed from molecule to form a double bond w/ contribution from the radical, propagation step
| opposite of addition to a pi bond
152
# chpt 10
Couping
| radical reactions
two radicals join together to form a bond, termination step
153
# chpt 10
Initiation
creation of radicals, start with none and end with some
154
# chpt 10
Propogation
movement of a radical around a molecule
155
# chpt 10
Termination
gets rid of radicals, start with some end with none
156
# chpt 10
what are the products and reagants of halogenation of an alkane?
reagnts: Br2 + light
products: alkyl halide + HX
| enantiomers if chiral carbon is created
157
# chpt 10
what are the mechanistic steps of halogenation of an alkane?
1. Homolytic clevage
2. hydrogen abstraction to form carbon radical
3. halogen abstraction to create alkyl halide
4. coupling
158
# chpt 10
Halogenation occurs at the --- substitued carbon for halogenation of an alkane
more substitued carbon, where more stable radical would be
159
# chpt 10
allylic bromination
the addition of bromine to an allylic positon on a compound by homolytic clevage of the weakest C-H bond
160
# chpt 10
regants and products of allylic bromination
reagants: an alkene + NBS and light
products: bromine on allylic postion with products from both radical resonance contributors
| NBS reduces addition products
161
# chpt 10
Mechanism for allylic bromination
1. initiation
2. hydrogen abstraction from weakest C-H bond
3. Halogen abstraction
4. termination
162
# chpt 10
Hydrohalogenation of an alkene w/ peroxides (ROOR)
anti markovnikov addition of HBr across a pi bond
163
# chpt 10
reagants and products of antimarkovnikov additon of HBr
reagants: alkene+ HBr and ROOR
products: anti markovnikov addition of HBR
164
# chpt 10
Mechanism for hydrohalogenation of an alkene using HBr and ROOR
1. initiaition, cleav O-O bond
2. hydrogen abstraction
3. addition of Br
4. hydrogen abstraction of H to more sub. position
5. termination
