Chemistry Reference
In-Depth Information
Fig. 3 Correlation between
theoretical and experimental
data of compounds 1
4.(a)
Experimental (
x
-axis) versus
theoretical (
y
-axis) bond
distances d of S-N bonds in
(
˚
). Best fit straight line:
y ¼
1.20
x
0.29; sample
correlation coefficient
R
2
a
1.75
1.70
1.65
1.60
1.55
¼
0.98. (b) Experimental
(
x
-axis) versus theoretical
(
y
-axis) densities r(
r
BCP
)of
S-N bonds in (e/
˚
3
). Best fit
straight line:
y
1.50
1.45
1.50
1.55
1.60
1.65
1.70
d
exp
(Å)
0.68
x
+ 0.98; sample
correlation coefficient
R
2
¼
b
1.9
0.68. The outlier is
from S1-N1 in 3. (c)
Experimental (
x
-axis) versus
theoretical (
y
-axis)
Laplacians
¼
1.8
1.7
2
(
r
BCP
) of the
S-N bonds in (e/
˚
5
). No
linear fit possible
r
r
1.6
1.5
1.4
1.7
1.8
1.9
2.0
2.1
2.2
2.3
2.4
exp
(e/Å
3
)
c
10
5
0
-5
-10
-15
-20
-15
-10
-5
2
exp
(e/Å
5
)
∇
be found for small basis sets, in some cases extending the basis sets increases the
deviations significantly. However, these deviations may also arise from the proper-
ties of the Pople-basis sets (see Tables
1
and
4
).
In summary, these investigations showed that a reliable and consistent determina-
tion of topological parameters of the ED is still problematic for polar bonds indepen-
dent of whether they are determined experimentally or with theoretical approaches.
The computed data depend strongly on the level of theory, while uncertainties within
