V-V process decreases with increasing m; ceteris paribus P $ 1=~ v. For ~ v ¼ 300 cm
À1
and D ~ v ¼ 10 À 20 cm
À1 , P 1,0 = 0.02; at ~ v ¼ 2300 cm
À1 and D ~ v ¼ 10 cm
À1
P 1,0 = 10
–3 .
On the effect of an energy defect on the probability of the V-V process. Both
from theory and from experiments it follows that lgð1=PÞ $ D~ v. So, if at ~ v ¼
2300 cm
À1 and D ~ v ¼ 10 cm
À1 , P 1,0 = 1 10
–3 , then at the same frequency and
D ~ v ¼ 600 cm
À1 P 1,0 = 2 10
–7 . It should be borne in mind that if an energy defect
occurs due to anharmonicity with an increase in of the vibrational quantum number,
as is the case in processes important for aeronomy
CO X
1 R
þ
; v
ð
ÞþCO X
1 R
þ
; v ¼ 0
ð
Þ!CO X
1 R
þ
; v À 1
ð
Þ þ CO X
1 R
þ
; v ¼ 1
ð
Þ
CO X
1 R
þ
; v
ð
ÞþN 2 X
1 R
þ
g ; v ¼ 0
! CO X
1 R
þ
; v À 1
ð
Þ þ N 2 X
1 R
þ
g ; v ¼ 1
N 2 X
1 R
þ
g ; v
þ N 2 X
1 R
þ
g ; v ¼ 0
! N 2 X
1 R
þ
g ; v À 1
þ N 2 X
1 R
þ
g ; v ¼ 1
(Tables 5.1, 5.2, 5.3), then an increase in the energy defect does not lead to a
sharp drop in the rate constant since the effect described above is compensated by
an increase in the constant due to an increase of the anharmonicity (see below).
Comparison of the V-T rate constants (see Sect. 5.1) in which initially unexcited
species remain unexcited with data given in Tables 5.1, 5.2, 5.3 shows that the latter
are several orders higher even there is no exact resonances in an exchange.
V-V processes in polyatomic molecules. Here we must add collision-induced
intramolecular energy transfer processes. We know that there are spontaneous
processes of stochastization of vibrational energy, but no energy loss occurs. For
quasi-resonant processes, there is no significant difference between these processes
in diatomic and polyatomic molecules (see Sect. 5.3 in [16]).
Table
5.1 The
rate
constant
V-V,
R
of
the
process
CO X
1 R
þ ; v
ð
Þþ
CO X
1 R
þ ; v ¼ 0
ð
Þ ! CO X
1 R
þ ; v À 1
ð
Þ þ CO X
1 R
þ ; v ¼ 1
ð
Þ , T = 300 K (see [9, 11–14])
v
DE
a , cm
−1
k, 10
–12 cm
3
/s
[9]
[ 11]
[ 12]
[ 13]
2
26.6
1.8
1.9
3.3 ± 0.5
3
53.2
2.2
4
79.7
2.0
2.1
5
106.3
1.3
1.5
6
132.9
0.63
0.85
7
159.5
0.34
0.4
a Energy deficit
162
5 Energy Transfer in Collisions
À1
and D ~ v ¼ 10 À 20 cm
À1 , P 1,0 = 0.02; at ~ v ¼ 2300 cm
À1 and D ~ v ¼ 10 cm
À1
P 1,0 = 10
–3 .
On the effect of an energy defect on the probability of the V-V process. Both
from theory and from experiments it follows that lgð1=PÞ $ D~ v. So, if at ~ v ¼
2300 cm
À1 and D ~ v ¼ 10 cm
À1 , P 1,0 = 1 10
–3 , then at the same frequency and
D ~ v ¼ 600 cm
À1 P 1,0 = 2 10
–7 . It should be borne in mind that if an energy defect
occurs due to anharmonicity with an increase in of the vibrational quantum number,
as is the case in processes important for aeronomy
CO X
1 R
þ
; v
ð
ÞþCO X
1 R
þ
; v ¼ 0
ð
Þ!CO X
1 R
þ
; v À 1
ð
Þ þ CO X
1 R
þ
; v ¼ 1
ð
Þ
CO X
1 R
þ
; v
ð
ÞþN 2 X
1 R
þ
g ; v ¼ 0
! CO X
1 R
þ
; v À 1
ð
Þ þ N 2 X
1 R
þ
g ; v ¼ 1
N 2 X
1 R
þ
g ; v
þ N 2 X
1 R
þ
g ; v ¼ 0
! N 2 X
1 R
þ
g ; v À 1
þ N 2 X
1 R
þ
g ; v ¼ 1
(Tables 5.1, 5.2, 5.3), then an increase in the energy defect does not lead to a
sharp drop in the rate constant since the effect described above is compensated by
an increase in the constant due to an increase of the anharmonicity (see below).
Comparison of the V-T rate constants (see Sect. 5.1) in which initially unexcited
species remain unexcited with data given in Tables 5.1, 5.2, 5.3 shows that the latter
are several orders higher even there is no exact resonances in an exchange.
V-V processes in polyatomic molecules. Here we must add collision-induced
intramolecular energy transfer processes. We know that there are spontaneous
processes of stochastization of vibrational energy, but no energy loss occurs. For
quasi-resonant processes, there is no significant difference between these processes
in diatomic and polyatomic molecules (see Sect. 5.3 in [16]).
Table
5.1 The
rate
constant
V-V,
R
of
the
process
CO X
1 R
þ ; v
ð
Þþ
CO X
1 R
þ ; v ¼ 0
ð
Þ ! CO X
1 R
þ ; v À 1
ð
Þ þ CO X
1 R
þ ; v ¼ 1
ð
Þ , T = 300 K (see [9, 11–14])
v
DE
a , cm
−1
k, 10
–12 cm
3
/s
[9]
[ 11]
[ 12]
[ 13]
2
26.6
1.8
1.9
3.3 ± 0.5
3
53.2
2.2
4
79.7
2.0
2.1
5
106.3
1.3
1.5
6
132.9
0.63
0.85
7
159.5
0.34
0.4
a Energy deficit
162
5 Energy Transfer in Collisions