Environmental Engineering Reference
In-Depth Information
Table 5.4
The dipole moment of some nitrate esters
Compounds
Dipole moment
μ
Compounds
Dipole moment
μ
(Debye)
(Debye)
Pure
Benzene
solution
Pure
Benzene
solution
N-butyl nitrate
2.90
2.98
Nitroglycerine
3.82
3.16
Glycol dinitrate
4.00
3.28
3-chloro-1,2-propylene
glycol dinitrate
3.46
3.05
1,3-propylene
glycol dinitrate
3.50
3.14
1,3-dichloro-2-propylene
glycol dinitrate
2.86
2.59
1,2-propylene
glycol dinitrate
4.24
3.72
Tribromopropane
1.63
1.58
1,3-butanediol
glycol dinitrate
3.74
3.45
Glycerol triacetate
2.50
2.58
2,3-butanediol
glycol dinitrate
4.72
4.12
nitrate esters, it has been demonstrated that the UV absorptivity of the esters that do
not include other luminophores is even lower than aliphatic nitro compounds
(
ʵ
=l0
-
20) (Table
5.5
).
Besides the UV spectroscopy of nitrate esters [
20
], researchers [
21
] have studied
infrared absorption characteristics of a series of nitrate esters from methyl nitrate to
n-butyl nitrate. Raman spectroscopy of nitrate esters and nitro compounds of ali-
phatic or aromatic nitrate has been investigated [
22
].
In the IR spectra of 20 nitrate esters, including monohydric alcohol nitrate,
dihydric alcohol nitrate, nitroglycerine, dipentaerythritol, and tripentaerythritol
[
23
26
],
the characteristic stretching frequency of
ONO
2
is at
the following
-
-
positions.
13 cm
1
Asymmetric
1,639
7cm
1
Symmetric
1,279
The stretching frequencies of glycol dinitrate and pentaerythritol tetranitrate are
at 1,650
1,250 cm
−
1
, respectively [
27
].
The results are in agreement with Raman spectra, in which two frequencies of
NO
2
characteristic vibration are at 1,640 and 1,290 cm
−
1
[
28
,
29
].
The author [
15
,
30
] studied more than 40 nitrate esters by spectroscopic method
to obtain their stretching vibration frequency range.
1,610 and 1,300
-
-
