Chemistry Reference
In-Depth Information
c
K
¼
0
:
6243
;
c
D
¼
0
:
2710
ð
9
:
130
Þ
finally giving the following as relative weights of the covalent
singlet structures in benzene:
38
:
9
% c
1
;
38
:
9
% c
2
;
7
:
4
% c
3
;
7
:
4
% c
4
;
7
:
4
% c
5
ð
9
:
131
Þ
So, the contribution of the Dewar structures, even if individually
small, is quite important on the whole. The results (9.131) are in
surprising agreement with recent ab initio VB calculations by
Cooper et al. (1986), which give for these weights 40.3% for
c
1,2
and 6.5% for
c
3-5
.
For the sake of comparison, the relative weights of the structures
resulting from all preceding VB calculations are collected in
Figure 9.10.
