Conformational energies. The solvent in parentheses in cases where large solvent dependence is observed.

 

Group

A-value (kcal/mol)

t (¼C)

D

0.006

25

T

0.011

-88

F

0.25-0.42

-86 to -93, -25

Cl

0.53-0.64

-80 to -93, 25-27

Br

0.48-0.67

-81, 25-27

I

0.47-0.61

-78, -93, 25

OH(C­6H12)

0.60

25

OH(CS2)

1.04

-83

OH(CH3CHOHCH3)

0.95

25

OCD3, OCH3

0.55, 0.58, 0.63, 0.75

-82, -93

OC(CH3)3

0.75

36

OC6H5

0.65

-93

OC6H4NO2-p

0.62

-93

OC6H4Cl-p

0.65

-93

OC6H4OCH3-p

0.70

-93

OCHO

0.27, 0.60

25, -80 to -93

OCOCH3

0.68, 0.71, 0.79, 0.87

25, -90 ± 3

OCOCF3

0.68, 0.56

25, -88 to -93

OCOC6H5

0.5

-92 ± 1

OCONHC6H5

0.77

-91

OSO2C6H5CH3-p

0.50

-80 to -83

OSO2CH3

0.56

-88

ONO2

0.59, 0.62

25, -101

OSi(CH3)3

0.74

-103

SH

1.21

-80

SCD3, SCH3

1.04

-79 to -100

SC6H5

1.10-1.24

-80

SOCH3

1.20

-90 to -100

SO2CH3

2.50

-90 to -100

SCN

1.23

-79

SeC6H5

1.0-1.2

-50

SeOC6H5

1.25

-60

TeC6H5

0.9

-30

NH2 (tol-d; CFCl3)

1.23, 1.47

-80 to -100

NH2 (CH3OCH2CH2OH/H2O)

1.7

20

NH3+

1.7-2.0

20-25

NHCH3 (CFCl3-CDCl3)

1.29

-80

N(CH3)2 (CFCl3-CDCl3)

1.53

-90

N(CH3)2 (CH3OCH2CH2OH/H2O)

2.1

20

NH(CH3)2+

2.4

20

NHCOC6H5

1.6

-90

NC

0.20

-80 to -93

NCO

0.44, 0.51

-70 to -80

N3

0.45-0.62

-183, -93

NCS

0.25

-79 to -93

N=CHCH(CH3)2

0.75

32

N=C=NC6H11

0.96

-80

NO2

1.1

-80 to -90, 25

PH2

1.6

-90, 27

P(CH3)2

1.5, 1.6

-90, 27

P(C6H5)2

1.8

37

PCl2

1.9, 2.0

-90, 27

P(OCH3)2

1.9; 1.5

-90, 27

O=P(C6H5)2

2.46

-80

S=P(C6H5)2

3.13

-102

CHO

0.56-0.73, 0.8

25

COCH3

1.02, 1.21, 1.52

-100, 25

CO2H

1.4

25

CO2-

2.0

25

CO2CH3

1.2-1.3

25, -78

CO2Et

1.1-1.2

25

COF

1.4-1.7

25

COCl

1.3

25

CN

0.2

-79 to -95

CCH

0.41-0.52

-91

CH=CH­2

1.49, 1.68

-100

CH=C=CH2

1.53

-80

CH3

1.74

27

CD3*

0.0115

25-27

CH2CH3

1.79

27

CH(CH3)2

2.21

27

C(CH3)3

4.7; 4.9

-120

CH2Br

1.79

27

CH2OH

1.76

27

CH2COH

1.72

27

CH2CN

1.77

27

CH2Si(CH3)3

1.65

27

CH2Sn(CH3)3

1.79

27

CH2Pb(CH3)3

1.81

27

CH2HgOAc

2.05

27

CF3

2.4-2.5

27

C6H5

2.8

-100, 700

CH2C6H5

1.68

-71

C6H11

2.2

36

SiH3

1.45; 1.52

-85, 75

Si(CH3)3

2.5

33

SiCl3

0.61

-80

Ge(CH3)3

2.1

-70

Ge(C6H5)3

2.90

Not given

Sn(CH3)3

1.0

-69 to -90

Sn(i-Pr)3

1.10

Not given

Sn(CH3)2C6H5

1.08

Not given

SnCH3(C6H5)2

1.20

Not given

Sn(C6H5)3

1.44

Not given

Pb(CH3)3

0.67

-69

HgOAc

0, -0.3

-79, -90

HgCl

-0.25

-90

HgBr

0

-79

MgBr(Et2O)

0.78

-75

MgC6H11(Et2O)

0.53

-82

*Difference between CH3 and CD3; CD3 has lesser equatorial preference than CH3.

 

Eliel, E. L., Wilen, S. H. & Mander, L. N. Stereochemistry of Organic Compounds, New York: Wiley & Sonds, 1994, p. 696-697.