and NO2 bonds in the syn conformer (C 2v ) are longest for the LiONO (1.272 Å)
molecule and gradually shorten in length which is reflected in much shorter value
(1.216 Å) for RbONO. For the anti conformer (C s ) the NO1 bond is longer than the
terminal NO2 bond. The difference between both bond lengths is 0.099 Å for
LiONO, 0.082 Å for NaONO, 0.063 Å for KONO and 0.060 Å for RbONO. The
values of the bond lengths are shown in Table 19.2.
The spatial organisation of the core and valence attractors in the MONO series
(M = Li, Na, K, Rb) obtained from topological analysis of ELF are compared in
Fig. 19.4 The core and valence attractors in the alkaline nitrites, MONO (M = Li, Na, K, Rb)
Table 19.2 N–O bond lengths and mean electron populations,
N, for the localisaton basins for the
N–O bond in alkaline metal nitrites M–ONO (MO1NO2, M = Li, Na, K, Rb)
No
Molecule
Conformer
r(N–O1)
[Å]
V(N,O1)
[e]
r(N–O2)
[Å]
V(N,O2)
[e]
1
LiONO
syn
1.272
1.56
1.272
1.56
anti
1.310
1.37
1.211
1.83
2
NaONO
syn
1.272
1.51
1.272
1.51
anti
1.302
1.41
1.220
1.77
3
KONO
syn
1.266
1.55
1.266
1.55
anti
1.289
1.43
1.226
1.72
4
RbONO
syn
1.261
1.55
1.261
1.55
anti
1.288
1.44
1.228
1.71
The topological analysis of ELF performed at the B2PLYP/aug-cc-pVTZ (LiONO, NaONO,
KONO) and B2PLYP/def2-TZVPPD(N,O),TZVall(Rb)//B2PLYP/def2-TZVPPD (RbONO)
computational levels
536
S. Berski and A.J. Gordon