Ochem Subject Test 1 And 2 "isomerism"

Front 1

isomerism

Back 1

same moleular formula but different in structure

either structureal isomer or
steroisomers

Front 2

steroisomers

Back 2

have same molecular formula and have same atomic connection

the maximum # of stereoisomer of comp is
2^n

n= number of chiral carbon

either configurational isomers or conformational isomers

Front 3

structural isomer

Back 3

have same molecular formula but different atomic connection.

have very differnt chemical and physical property
different b.p

aka constitutional isomer

Front 4

conformational isomer

Back 4

only differ in rotation

staggered or eclipsed (newman projection)

Front 5

configuratonal isomer

Back 5

either enantiomers or diastereomers

Front 6

enantiomers

Back 6

non superimposable mirror image like your hand

same property except optical activity

R and S

Front 7

chirality

Back 7

거울상이 서로 겹치지않는 성질

Front 8

stereogenic center

Back 8

탄소원자에 4개의 다른 둰자단이 결합에 있을때

Front 9

diastereomers

Back 9

have different physical property

superimposible mirror image

-geometric isomers

Front 10

geometric isomers

Back 10

cis or trans and E or Z

different arrangement in double bond

cis/trans must have 1 H each side.

E/Z compare highest priority substituents

Front 11

staggered (anti)

Back 11

most stable

Front 12

order of stablity

Back 12

staggered (anti) >staggered (gauche) > eclipse (120 degree)> eclipse (0 degree)

Front 13

cyclic conformation

Back 13

boat and chair

chair (cyclohexane) most stable

envelop (cyclopentane)

Front 14

equatorial and axial position

Back 14

bulky group favors equatorial position over axaial b/c of steric repulsion w/ other axial subsitute

Front 15

chiral carbon

Back 15

have plane of symmetry=achiral (3diff sub)
-identical to its mirror image

no plane of symmetry=chiral
(4 different sub)
-enantiomers

Front 16

absolute configuration

Back 16

R and S

1. assigned priority
-higher atomic # takes precedence orver lower atomic #

2. have H point outward

3. more around the molecule from high to low

4. R if rotate left
S if rotate right

5. if H is inward then change S to R and R to S

Front 17

2 or mor chiral carbon

Back 17

if R <-> S
R S
then enantiomers

if R <-> R or R <-> S
R S R R
then diastereomers

Front 18

reletive and absolute config

Back 18

relitive config is change only if the bond of chiral atom is broken

absolute config is change only if R or S config is changed

Front 19

optical activity

Back 19

ability to rotate plane polarized light

R and S shows optical activity

meso compound= no optical activity

recemic mixture
-has both R and S, no optical activity because they cancel out

Front 20

recemic mixture

Back 20

mixture that contains equal amt of S and R enantiomers which cancel out thus no optical activity

Front 21

meso compound

Back 21

compound that possess chiral center but are still nonetheless achiral

possess a plane of symmetry

Front 22

most simliar to most differnt in isomers

Back 22

conformation most similar
enantiomer
diasteromer (meso and geometric)

structural most differnt

Front 23

cis and trans in cyclic compound

Back 23

trans isomer is more stable b/c van der walls repulsion btw sub is minimized

Front 24

Geometric isomer

Back 24

differ the arrangement of group s around a double bond

Z = same side
E = opposite site
(compareing large group)

Cis and Trans
(comparing large group to H)

Front 25

2^n ??

Back 25

# of stereoisomer

n= number of chiral atom

Front 26

different physical and chemical property

Back 26

structural(constitutional) isomer

Front 27

different physical property

Back 27

diasteromer

Front 28

same property except optical activity

Back 28

eantiomer