|
SPECTROSCOPY |
7.23 |
|
TABLE 7.13 |
Solvent Correction for Ultraviolet- |
|
|
|
Visible Spectroscopy |
|
|
|
|
|
|
Solvent |
Correction, nm |
|
|
|
|
|
|
Chloroform |
1 |
|
|
Cyclohexane |
|
|
|
Diethyl ether |
11 |
|
|
1,4-Dioxane |
5 |
|
|
Ethanol |
0 |
|
|
Hexane |
11 |
|
|
Methanol |
0 |
|
|
Water |
8 |
|
|
|
|
|
|
TABLE 7.14 Primary Bands of Substituted Benzene and Heteroaromatics
In methanol.
Base value: 203.5 nm.
|
Wavelength |
|
Wavelength |
Substituent |
shift, nm |
Substituent |
shift, nm |
|
|
|
|
9CH3 |
3.0 |
9COOH |
25.5 |
9CH"CH2 |
44.5 |
9COO |
20.5 |
9C#CH |
44 |
9CN |
20.5 |
9C6H5 |
48 |
9NH2 |
26.5 |
9F |
0 |
9NH3 |
0.5 |
9Cl |
6.0 |
9N(CH3)2 |
47.0 |
9Br |
6.5 |
9NH9CO9CH3 |
38.5 |
9I |
3.5 |
9NO2 |
57 |
9OH |
7.0 |
9SH |
32 |
9O |
31.5 |
9SO9C6H5 |
28 |
9OCH3 |
13.5 |
9SO2CH3 |
13 |
9OC6H5 |
51.5 |
9SO2NH2 |
14.0 |
9CHO |
46.0 |
9CH"CH9C6H5 |
|
9CO9CH3 |
42.0 |
cis |
79 |
9CO9C6H5 |
48 |
trans |
92.0 |
|
|
9CH"CH9COOH, trans |
69.5 |
|
|
|
|
|
Base value, |
|
Base value, |
Heteroaromatic |
nm |
Heteroaromatic |
nm |
|
|
|
|
Furan |
200 |
Pyridine |
257 |
Pyrazine |
257 |
Pyrimidine |
ca 235 |
Pyrazole |
214 |
Pyrrole |
209 |
Pyridazine |
ca 240 |
Thiophene |
231 |
|
|
|
|
7.24 |
SECTION 7 |
TABLE 7.15 Wavelength Calculation of the Principal Band of Substituted Benzene Derivatives
In ethanol.
Base value of parent chromophore, nm |
|
C6H5COOH or C6H5COO9alkyl |
230 |
C6H5 9CO9alkyl (or aryl) |
246 |
C6H5CHO |
250 |
Increment (in nm) for each substituent on phenyl ring |
|
9Alkyl or ring residue |
|
o-, m- |
3 |
p- |
10 |
9OH and 9O9 alkyl |
|
o-, m- |
7 |
p- |
25 |
9O |
|
o- |
11 |
m- |
20 |
p- |
78* |
9Cl |
|
o-, m- |
0 |
p- |
10 |
9Br |
|
o-, m- |
2 |
p- |
15 |
9NH2 |
|
o-, m- |
13 |
p- |
58 |
9NHCO9CH3 |
|
o-, m- |
20 |
p- |
45 |
9NHCH3 |
|
p- |
73 |
9N(CH3)2 |
|
o-, m- |
20 |
p- |
85 |
* Value may be decreased markedly by steric hindrance to coplanarity.