Chemistry Reference
In-Depth Information
TABLE 6.10. Singlet-Triplet Energy Gaps in Heteroaryl Nitrenium Ions
51
D
E
st
(BPW91/cc-PVDZ) (kcal/mol)
a
Heteroaryl Nitrenium Ion
14.5
H
N
N
82
6.0
H
N
N
83
3.6
H
N
N
84
þ
5.4
H
N
N
N
85
þ
7.0
H
N
NN
86
þ
0.8
H
N
NN
87
þ
10.9
H
N
N
N
N
88
a
A negative value implies a singlet ground state.
6.9 CONCLUSIONS
The last two decades have seen enormous progress in characterizing the electronic
properties of nitrenium ions. Computational methods have drastically improved in
both accuracy and efficiency such that it is possible to predict the structures and
electronic states of highly substituted nitrenium ions as well as to identify broad
trends. More significantly, modern computational packages now provide means of
calculating properties such as UV-Vis spectra and IR or Raman spectra that can be
readily verified by experimental methods.
