n A þ
m AB !
m A þ
n AB
ð7:1:2Þ
(here n, m are the masses of isotopes A, n 6 ¼ m).
Often, chemiluminescent reactions also mean processes of electronic deactivation with energy transfer (see Sect. 5.7), leading to the decay of the excited states of
some species, the appearance of vibrational-rotational, electronic or rovibronic
excitation in others
A
Ã
þ BC ! A þ BC
#
ð7:1:3aÞ
! A þ BC
Ã
ð7:1:3bÞ
and accompanied by the emission of a photon in the IR (reaction 7.1.3a) or visible,
UV spectral regions (reaction 7.1.3b). In the author’s opinion, this is incorrect
methodologically.
There is a thin line between the collision-induced optical transition (Fig. 7.1a,
process 1) and a kind of chemiluminescent reaction, namely, inverse dissociation by
repulsive state (see below). In the first case, if one of the species is an excited atom,
an atomic line broadened due to the collision is observed (the collision weakens the
forbiddance of the optical transition). In the second case, a wide molecular band
occurs. Obviously, with an increase in the colliding partner kinetic energies, A 2 and
B 2 atoms, for example (Fig. 7.1a) the A 2 -B 2 internuclear distance can decrease to
small values, and along with the atomic line, a molecular band will also be
observed. If an excited species is polyatomic one, then it is much more difficult to
distinguish these processes.
Chemiluminescent reactions in the gas phase are divided into exchange
chemiluminescence and recombination accompanied by radiation (radiative
recombination [1], p. 108).
2. Bimolecular exchange reactions are reactions some of the products of which are
formed in vibrational-rotational, electronic, or rovibronic excited states:
A þ BC ! AB þ C
Ã
ð7:1:4Þ
! AB
Ãð#Þ
þ C;
ð7:1:5Þ
AB þ CD ! AC þ B
Ã
þ D
ð7:1:6Þ
! AC þ BD
Ãð#Þ
ð7:1:7Þ
Examples of such reactions are processes [2]
Sn
3 P
À Á þ N 2 O ! SnO a
3 R
þ
;
3 P
À
Á þ N 2 X
1 R
þ
g
ð7:1:8Þ
266
7 Chemiluminescence
m AB !
m A þ
n AB
ð7:1:2Þ
(here n, m are the masses of isotopes A, n 6 ¼ m).
Often, chemiluminescent reactions also mean processes of electronic deactivation with energy transfer (see Sect. 5.7), leading to the decay of the excited states of
some species, the appearance of vibrational-rotational, electronic or rovibronic
excitation in others
A
Ã
þ BC ! A þ BC
#
ð7:1:3aÞ
! A þ BC
Ã
ð7:1:3bÞ
and accompanied by the emission of a photon in the IR (reaction 7.1.3a) or visible,
UV spectral regions (reaction 7.1.3b). In the author’s opinion, this is incorrect
methodologically.
There is a thin line between the collision-induced optical transition (Fig. 7.1a,
process 1) and a kind of chemiluminescent reaction, namely, inverse dissociation by
repulsive state (see below). In the first case, if one of the species is an excited atom,
an atomic line broadened due to the collision is observed (the collision weakens the
forbiddance of the optical transition). In the second case, a wide molecular band
occurs. Obviously, with an increase in the colliding partner kinetic energies, A 2 and
B 2 atoms, for example (Fig. 7.1a) the A 2 -B 2 internuclear distance can decrease to
small values, and along with the atomic line, a molecular band will also be
observed. If an excited species is polyatomic one, then it is much more difficult to
distinguish these processes.
Chemiluminescent reactions in the gas phase are divided into exchange
chemiluminescence and recombination accompanied by radiation (radiative
recombination [1], p. 108).
2. Bimolecular exchange reactions are reactions some of the products of which are
formed in vibrational-rotational, electronic, or rovibronic excited states:
A þ BC ! AB þ C
Ã
ð7:1:4Þ
! AB
Ãð#Þ
þ C;
ð7:1:5Þ
AB þ CD ! AC þ B
Ã
þ D
ð7:1:6Þ
! AC þ BD
Ãð#Þ
ð7:1:7Þ
Examples of such reactions are processes [2]
Sn
3 P
À Á þ N 2 O ! SnO a
3 R
þ
;
3 P
À
Á þ N 2 X
1 R
þ
g
ð7:1:8Þ
266
7 Chemiluminescence