Environmental Engineering Reference
In-Depth Information
b
j
b
φφ
j
Fragment
b
j
b
j
, Other Types
(d) Nitrogen increments
−
N
<
−
2.18
−
0.93
−
0.50
−
N
<
aromatic
−
1.12
−
NH
−
−
2.15
−
1.03
−
0.09
−
NH-aromatic
0.65
Benzyl
c
−
NH
2
−
−
1.54
−
1.00
−
1.35
−
NO
2
−
1.16
−
0.03
−
CN
−
1.27
−
0.34
Benzyl
−
0.88
(e) Halogen increments
−
Cl
0.06
0.94
Vinyl 0.50
−
Br
0.20
1.09
Vinyl 0.64
Feature
B
k
Structural Factors
(a) Geometric features
Multiple bond (unsaturation)
Double bond
−
0.09
d
−
0.50
d
Triple bond
Skeletal flexing
Hydrocarbon chains
−
(
N
−
1
)
(0.12)
e
Alicyclic rings
−
(
N
−
1
)
(0.19)
Chain branching
Nonpolar chain
−
0.13
Polar chain
−
0.22
(b) Electronic features
Polyhalogenation
2 on the same C
0.60
3 on the same C
1.59
4 on the same C
2.88
2 on adjacent sp
3
C
0.28
3 on adjacent sp
3
C
0.56
4 on adjacent sp
3
C
0.84
Polar Fragments
In Chain
In Aromatic Ring
On same C
−
0.42(b
1
+
b
2
)
On adjacent C
−
0.26(b
1
+
b
2
)
−
0.16(b
1
+
b
2
)
On C separated by one C
−
0.10(b
1
+
b
2
)
−
0.08(b
1
+
b
2
)
Intramolecular hydrogen bonding
With
−
OH 1.0
With
−
NH 0.6
a
The superscript
φ
denotes attachment to an aromatic ring (e.g., C
6
H
5
−
O
−
).
φφ
denotes fragment
to two aromatic rings (e.g., C
6
H
5
−
CO
−
C
6
H
5
). Values are adapted from Lyman et al. (1990) and
Baum (1998).
b
Contribution of C shared by aromatic rings is 0.225, for C shared by aromatic rings and bonded to a
hetero atom or a nonisolating C is 0.44.
c
Vinyl means an isolated double bond
>
C
=
C
<
, benzyl means C
6
H
5
CH
2
−
group.
d
Value includes deductions for removing hydrogen atoms to produce unsaturation.
e
N
denotes the number of bonds in chain or ring.
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