Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Organic chemistry > exam 2: Ch 4 & 14 > Flashcards

exam 2: Ch 4 & 14 Flashcards

1
Q

polycyclic ring systems

A

classified by the number of rings they contain
named by how many bond disconnections to make a linear structure (bicyclic, tricylic)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

fused ring systems

A

share a bond

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

bridged ring system

A

connected at 2 nonadjacent atoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

spirocyclic ring system

A

share a single C atom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

heteroaromatic rings

A

aromatic rings that include 1+ heteroatom
have resonance structures, incorporating lone pair on heteroatom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

newman projections

A

toward = right side

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

chair conformations

A

up C have up axial H and down equatorial H
ring flip: axial becomes equatorial, but up stays up
stable when most and largest groups are equatorial
up = wedge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

fischer projections

A

horizontal = wedge/towards
vertical = dashed/away
orient so C chain is vertical with lowest numbered C at the top

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

chiral C/stereoisomer

A

C with 4 different groups
not part of a multiple bond
if in a ring, different path in both directions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

plane of symmetry

A

if present, achiral
cuts through molecule such that one half is the mirror of the other

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

number of stereoisomers

A

2^# of stereocenters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Cahn Ingold Prelog Rules

A

rank atoms bound to stereocenter according to atomic number, highest first
orient molecule so lowest priority is facing away
draw arrow 1 through 3
clockwise: R
counterclockwise: S

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

enantiomer

A

kind of stereoisomer
chiral molecule
opposite chirality at all stereoisomers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

diastereomers

A

stereoisomer that is not a mirror image
draw by changing chirality of some of the stereocenters
cis and trans are diastereomers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

meso compound

A

achiral molecule with chirality centers
mirror image is identical to itself, no enantiomer
contain at least 2 chiral centers and a plane of symmetry

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

physical properties

A

enantiomers have the same physical properties, except optical purity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

optical purity/activity

A

ability to rotate plain polarized light
substance must be chiral and one enantiomer must be in excess
(specific rotation of sample)/(specific rotation of pure enantiomer)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

enantiomeric ratio (er)

A

%major enantiomer : %minor enantiomer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

enantiomeric excess (ee)

A

%major enantiomer - %minor enantiomer
0 when it’s 50/50 (racemic mixture)
100 when there’s a single enantiomer (enantiopure)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

IR spectroscopy

A

vibration of a bond is related to strength
good for identifying functional groups

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Hooke’s Law

A

frequency is directly related to force constant and indirectly related to mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

force constant (k)

A

stiffness = bond strength
increase bond strength, increase frequency
influenced by hybridization, resonance, nearby EN

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

reduced mass (m1 and m2)

A

mass of either side of the bond
decrease mass, increase frequency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

hybridization and frequency

A

more s character (sp) increases k, which increases frequency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

resonance and frequency

A

reduces double bond character, decreases k, which decreases frequency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

nearby EN and frequency

A

pulls e-, reducing contribution from a single bond resonance form, increases k and frequency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what increases intensity

A

changes in dipole moment

28
Q

carbonyl compounds (C=O)

A

1650 - 1800
resonance: atoms with lone pairs next to carbonyl decrease C=O frequency
inductive: EN atom near carbonyl will increase frequency

29
Q

O-H frequency

A

3300 - 3600, broad

30
Q

N-H frequency

A

3400
amide or amine

31
Q

C-N frequency

A

1350 - 1000

32
Q

C - O frequency

A

1300 - 1000
ether

33
Q

sp2 C-H frequency

A

3100

34
Q

C=C frequency

A

1650

35
Q

sp CH frequency

A

3300

36
Q

C triple C frequency

A

2150

37
Q

out of plane bending

A

900 - 690

38
Q

arene C=C

A

1600 and 1475

39
Q

chemical equivalence

A

if there is a symmetry operation or a symmetry element that interchanges them

40
Q

integration

A

area under peak
relative # of H in a particular chemical environment

41
Q

n+1 rule (multiplicity)

A

number of peaks -> singlet, doublet, triplet
peaks - 1 = # of neighboring H

42
Q

chemical shift

A

environment of H, how shielded
adjacent EN moves shift downfield
more s character moves shift downfield

43
Q

number of signals in H NMR

A

number of different H

44
Q

spin spin splitting

A

arises from interactions of neighboring nuclear nuclei (nonequavalent)

45
Q

what does intensity depend on

A

intensity of each peak in a multiplet depends on how many spin arrangements give the same energy

46
Q

coupling constant (J)

A

extent two nuclei are coupled
space between two peaks, must be equal

47
Q

diastereotopic protons

A

if switch one H out, get diastereomers
give rise to different signals
leaning, not quartet

48
Q

OH and NH IR signals

A

broad, do not include any coupling issues

49
Q

conformers

A

rapid conversion -> one signal for axial and equatorial H (when no substituents)

50
Q

number of signals in C NMR

A

number of different types of C

51
Q

chemical shift in C NMR

A

adjacnet EN shifts downfield
ring carbon opposite to substituent shifts downfield
e withdrawing - e donating
sp2 - sp - sp3

52
Q

DEPT

A

type of attached proton
45: C with H
90: CH
135: CH and CH3 as pos, CH2 as neg

53
Q

HSQC

A

correlation between H and C signals
cross peak means the H are coupled to a particular C

54
Q

unsaturation

A

CnH2n+1
1/2(normal H - given H)
oxygen doesn’t matter
halogen takes place of an H
N adds an H

55
Q

mass spectrometry

A

groups seperated by mass, identify molecular weight of fragments
largest mass (right) = molecular weight of compound (parent ion)

56
Q

mass to charge ratio (m/z)

A

x axis of mass spec

57
Q

base peak

A

most intense peak, assigned a relative intensity of 100
benzene: m/z = 78

58
Q

isotopic cluster

A

a group of peaks that differ in m/z bc they incorporate different isotopes of their elements

59
Q

chlorine

A

100/32.7 (3:1)

60
Q

bromine

A

100/97.5 (1:1)

61
Q

presence of N

A

molecule weight of a substance that contains C, H, O and N is odd if the number of N is odd

62
Q

sp3 CH ppm

A

1.2

63
Q

sp CH ppm

A

1.2 - 2.7

64
Q

sp2 CH ppm

A

5

65
Q

benzene ppm

A

8.2

Organic chemistry (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions