A new perfluorinated peroxynitrate, CF3CF2CF2CF2OONO2. Synthesis, characterization and atmospheric implications

Article abstract of DOI:10.1016/j.chemphys.2014.06.011

CF3CF2CF2CF2OONO2 was synthesized from the photolysis of CF3CF2CF2CF2I, in presence of NO2 and O2. Alkyl peroxynitrates (CxF2x+1OONO2) could be formed in the atmospheric degradation of chlorofluorocarbons, hydrofluorocarbons and hydrofluoroethers. We present here the synthesis and characterization (IR and UV absorption cross sections) of CF3CF2CF2CF2OONO2 and its comparison with those corresponding to other perfluoro alkyl peroxynitrates. The thermal stability was studied as a function of total pressure (from 9.0 to 417 mbar) and temperature (from 283 to 293 K) using infrared spectroscopy. Kinetic parameters measured for the thermal dissociation were Ea = (81 ± 4) kJ/mol and A = 4.8 × 1012. DFT calculations at the B3LYP/6-311+Ga.

Full text of DOI:10.1016/j.chemphys.2014.06.011

Chemical Physics 441 (2014) 11–16
Contents lists available at ScienceDirect
Chemical Physics
journal homepage: www.elsevier.com/locate/chemphys
A new perfluorinated peroxynitrate, CF3CF2CF2CF2OONO2. Synthesis,
characterization and atmospheric implications
⇑
Adriana G. Bossolasco, Jesús A. Vila, Maxi A. Burgos Paci, Fabio E. Malanca , Gustavo A. Argüello
Instituto de Investigaciones en Fisicoquímica de Córdoba (INFIQC), CONICET – Departamento de Fisicoquímica, Facultad de Ciencias Químicas (Universidad Nacional de Córdoba),
Ciudad Universitaria, X5000HUA Córdoba, Argentina
a r t i c l e i n f o
a b s t r a c t
Article history:
CF3CF2CF2CF2OONO2 was synthesized from the photolysis of CF3CF2CF2CF2I, in presence of NO2 and O2.
Alkyl peroxynitrates (CxF2x+1OONO2) could be formed in the atmospheric degradation of chlorofluorocar-
bons, hydrofluorocarbons and hydrofluoroethers. We present here the synthesis and characterization (IR
and UV absorption cross sections) of CF3CF2CF2CF2OONO2 and its comparison with those corresponding
to other perfluoro alkyl peroxynitrates. The thermal stability was studied as a function of total pressure
(from 9.0 to 417 mbar) and temperature (from 283 to 293 K) using infrared spectroscopy. Kinetic param-
eters measured for the thermal dissociation were Ea = (81 4) kJ/mol and A = 4.8 ꢀ 1012. DFT calculations
at the B3LYP/6-311+G⁄ level were used to explore the ground state potential energy surface. Geometrical
parameters, conformer populations and vibrational spectra are presented. The calculated activation
energy was 81.3 kJ molꢁ1 in excellent agreement with experimental results. Atmospheric implications
are discussed.
Received 3 April 2014
In final form 16 June 2014
Available online 2 July 2014
Keywords:
Perfluoro alkyl peroxynitrate
CF3CF2CF2CF2OONO2
Thermal decomposition
Kinetic parameters
Ó 2014 Elsevier B.V. All rights reserved.
1. Introduction
spectra and atmospheric lifetimes for perfluoro alkyl peroxyni-
trates (CxF2x+1OONO2), with x = 1 [8,13–15] and x = 2, 3 [16,11].
Peroxynitrates are formed in the degradation of volatile com-
pounds emitted to the atmosphere, and are important reservoirs
of peroxy radicals and NO2. Precisely due to their stability (from
hours to days in the free atmosphere), they can reach higher
altitudes where lower temperatures stabilize the molecules and
consequently they can be transported to remote places [1–3].
The loss of peroxynitrates in the atmosphere occurs through
different processes, namely thermal decomposition, photolysis,
and reaction with OH radicals, whose relative importance depends
on the region of the atmosphere and the nature of the peroxyni-
trate [4–7]. Perfluoro acyl (CxF2x+1C(O)OONO2) and perfluoro alkyl
(CxF2x+1OONO2) peroxynitrates are important families that could
be formed in the degradation of a series of compounds used as
refrigerants, blowing and cleaning agents, emulsifiers and solvents
[8–11]. In particular, the degradation of n-CF3CF2CF2CF2H (HFC-
329p), an HFC with a lifetime of 33 years, leads to perfluorinated
Within this context, we present here the synthesis of the perfluoro
n-butyl peroxynitrate (CF3CF2CF2CF2OONO2) as well as its charac-
terization to extend the study of this family.
CF3CF2CF2CF2OONO2 was formed by the reaction between
CF3CF2CF2CFÅ radicals and O2 (Reaction (1))
2
CF3CF2CF2CFÅ þ O2 ! CF3CF2CF2CF2OOÅ
ð1Þ
2
followed by the reaction with NO2 (Reaction (2))
CF3CF2CF2CF2OOÅ þ NO2 ! CF3CF2CF2CF2OONO2
ð2Þ
Our results provided infrared and ultraviolet spectra, thermal
stability – as a function of the temperature and pressure – and
atmospheric lifetimes – as a function of altitude.
radicals, CF3CF2CF2CFÅ [12], and subsequent reactions with O2
2. Experimental
2
and NO2 could give rise to the corresponding perfluoro alkyl
peroxynitrate, CF3CF2CF2CF2OONO2. Previous studies reported the
synthesis and characterization, thermal stability, UV and infrared
2.1. Photochemical synthesis of CF3CF2CF2CF2OONO2
Commercially available samples of CF3CF2CF2CF2I (Sigma–
Aldrich), O2 (AGA) and NO (AGA) were used, all of them with a
purity higher than 98%. NO2 was prepared adding O2 to NO with
further purification obtaining a sample with 99% purity. Volatile
⇑
Corresponding author. Tel.: +54 3515353866.
E-mail address: fmalanca@fcq.unc.edu.ar (F.E. Malanca).
http://dx.doi.org/10.1016/j.chemphys.2014.06.011
0301-0104/Ó 2014 Elsevier B.V. All rights reserved.

12
A.G. Bossolasco et al. / Chemical Physics 441 (2014) 11–16
materials and gases were manipulated in a conventional glass
vacuum line.
employed. The vibrational frequencies informed were taken from
the G09 output without additional corrections.
Perfluoro n-butyl peroxynitrate was synthesized by the photol-
ysis of mixtures containing perfluoro n-butyl iodide, CF3CF2CF2CF2I,
(7.0 mbar), NO2 (3.5 mbar) and O2 (1000 mbar) in a 12 L reactor
using an internal 40 W low pressure mercury lamp (kmax = 254 nm)
located in a double walled quartz jacket through which flowing
water maintained constant temperature. The procedure to synthe-
size the CF3CF2CF2CF2OONO2 was similar to that used by Mayer-
Figge et al. for CF3OONO2 [13]. The quartz jacket closed the 12 L
glass reactor through a tapered joint and the photolyses were car-
ried out maintaining the temperature at 278 K to minimize the
thermal decomposition of CF3CF2CF2CF2OONO2.
The progress of the synthesis was monitored by infrared spec-
troscopy (Bruker IFS 66v FTIR Spectrometer) using a standard
infrared gas cell (optical path, l = 23 cm), by taking small fractions
of the mixture every 5 min. The irradiation was stopped when the
NO2 signal decreased to one third of the initial value (ꢂ30 min), to
assure that NO2 concentration is still sufficiently high to prevent
the decomposition of the peroxynitrate (Reaction (-2)) and to shift
the equilibrium to the re-formation of the peroxynitrate:
3.1. Thermal decomposition
Thermal decompositions of CF3CF2CF2CF2OONO2 were carried
out at temperatures ranging between 283 and 293 K, adding NO
(3.0 mbar) to prevent the occurrence of reaction (2) through the
capture of the peroxy radicals formed
CF3CF2CF2CF2OOÅ þ NO ! CF3CF2CF2CF2OÅ þ NO2
ð4Þ
as done for other peroxy radicals [22], and monitoring the temporal
variation of the peroxynitrate by infrared spectroscopy. The pres-
sure was set from 9.0 to 417 mbar, adding He in order to study
the pressure dependence.
4. Results and discussion
4.1. Photochemical synthesis of CF3CF2CF2CF2OONO2
Fig.
1 shows the mixture at t = 0 min (upper trace) and
CF3CF2CF2CF2OONO2 ¡ CF3CF2CF2CF2OOÅ þ NO2
ð-2; 2Þ
t = 30 min irradiation (second trace), and the sequence of spectra
used to identify the products of the synthesis. The third trace,
which corresponds to the products, was obtained by subtraction
of reference spectra for CF3CF2CF2CF2I and NO2 to the second
one. It is clear the appearance of peaks corresponding to carbonyl
fluoride (CF2O), and perfluoro alkyl peroxynitrates (signals at
1764 and 790 cmꢁ1). Being so evident the formation of CF2O, there
should have formed also a species with less than four carbon
atoms. The most likely candidate is CF3CF2CF2OONO2; therefore
subtraction of the spectra of CF2O and CF3CF2CF2OONO2 (from
our repository of pure substances [11]) reveals the formation of a
new peroxynitrate, which was assigned to CF3CF2CF2CF2OONO2,
as will be discussed below.
The resultant mixture of photolysis was collected by slowly
passing it through three traps kept at 77 K in order to remove
excess O2. It was then distilled trap to trap between 188 and
153 K to eliminate the CF2O. Further distillation using three traps
at 213, 193 and 173 K allows obtaining CF3CF2CF2CF2OONO2 in
the fraction at 173 K.
2.2. IR and UV spectroscopy
The experimental IR and UV absorption cross sections were
obtained from measurements of absorbances at 300 K, according
to Eq. (3)
The carbonyl fluoride (CF2O) and CF3CF2CF2OONO2 formed
(though in moderate quantities, ꢂ9%), are a consequence of a series
of reactions initiated by the slow thermal decomposition of
CF3CF2CF2CF2OONO2. The peroxy radicals formed by reaction (-2)
could either react with NO (originated from the photolysis of
Abs ꢀ TðKÞ ꢀ 31; 7 ꢀ 10ꢁ20
r
ðcm2 molecꢁ1Þ ¼
ð3Þ
pðmbarÞ ꢀ lðcmÞ
where ‘‘p’’ denotes the pressure, and ‘‘T’’ the temperature. The pres-
sures of CF3CF2CF2CF2OONO2 ranged from 0.5 to 3.0 mbar, and the
cross sections were conveniently averaged. Infrared spectra were
recorded with a resolution of 2 cmꢁ1 averaging 16 scans in the
range of 4000–400 cmꢁ1. UV spectra were recorded from 200 to
282 nm with a resolution of 1 nm.
NO2,
r
254 nm = 1.08 0.07 ꢀ 10ꢁ20 cm2 moleculeꢁ1), iodine atoms
(k = (3.7 0.8) ꢀ 10ꢁ11 cm3 moleculeꢁ1 sꢁ1) consequence of the
t= 0 min
3. Computational details
t =30 min
Density functional theory has been used to evaluate the ground
state geometrical parameters, vibrational frequencies and the ther-
mal populations of many of the conformers of CF3CF2CF2CF2
OONO2. The hybrid density functional B3LYP with the 6-311+G⁄
basis set was employed in all calculations. DFT methods have been
extensively employed to describe fluoro-oxigenated systems
showing acceptable precision [17–19]. Only minimum points of
the potential energy surface (PES) were explored, confirmed by
no imaginary frequencies in the hessian matrix.
A
CF2O
B
CF3CF2CF2OONO2
C
When using first principle calculations without explicit treat-
ment of correlation energy to describe bond breaking processes,
the spin contamination from the generated radicals would cause
significant errors in the computed energies. To attenuate this effect
unrestricted wavefunctions and mixing of the Homo–Lumo molec-
ular orbitals were employed to study the ROANO2 bond fission.
Calculations were run without symmetry restrictions. The G09 pro-
gram package [20] in conjunction with GaussView 5.0 [21] were
1800
1500
1200
900
600
ν ( cm-1 )
Fig. 1. Photolysis of CF3CF2CF2CF2I in the presence of NO2 and O2. From top to
bottom: before photolysis; after 30 min of irradiation; products (A); CF2O reference
spectrum; A minus CF2O (B); CF3CF2CF2OONO2 reference spectrum; and B minus
CF3CF2CF2OONO2 (C).

A.G. Bossolasco et al. / Chemical Physics 441 (2014) 11–16
13
sp2 [8,11,14]. The calculated value of this parameter is 104.7° for
C4F9OONO2 and it is in perfect agreement with this tendency. The
OAN distance is extremely long in peroxynitrates and it has been
observed that it depends on the electronegativity of the group
attached to the –ONO2 fragment. Reported values of 1.507 and
1.523 Å are found for FONO2 and CF3OONO2 respectively [14,24].
In the case of C4F9OONO2 a value of 1.561 Å is found, which is
almost the same as for C3F7OONO2 within the calculated uncer-
tainty, and larger than the experimental value for CF3OONO2. A sep-
arate DFT calculation for CF3OONO2, C2F5OONO2 and C3F7OONO2
with the same basis set gives 1.560 Å for the OAN distance, showing
that addition of CF2 groups to the carbon chain does not influence
the OAN distance at the B3LYP/6-311+G⁄ method level. It can also
be mentioned that this method overestimates the OAN distance
when it is compared with the experimental value for CF3OONO2
(1.523 Å). Unfortunately there are not experimental studies for
the evaluation of the geometries of the series CxF2x+1OONO2 with
x = 2–4 and therefore these studies would have a lot of worth.
photochemical rupture of the precursor
(r254 nm = (3.86 0.07)
ꢀ 10ꢁ19 cm2 moleculeꢁ1) [23], or recombine to give CF3CF2CF2 CF2OÅ
radicals, which in turn decompose as in reaction (5)
CF3CF2CF2CF2OÅ ! CF3CF2CFÅ þ CF2O
ð5Þ
2
The CF3CF2CFÅ radicals lead finally to the formation of CF3CF2
2
CF2OONO2 following the established sequence of reactions with
O2 and NO2. The complete mechanism reaction is presented in
Fig. 2.
4.2. DFT calculations
The conformational space of CF3CF2CF2CF2OONO2 has been
studied taking into account the six main dihedral angles of the
skeleton FACF2ACF2ACF2ACF2AOAOANAO, which can be reduced
to four according to what follows. Previous studies for similar per-
oxynitrates [11,14] have shown that
u1(FACF2ACF2ACF2) always
adopts the anti configuration and
u
6(OAOANAO) the syn one.
The four remaining dihedrals are:
u2(CF2ACF2ACF2ACF2) which
u3(F2CACF2ACF2AO) which
4.3. IR and UV spectroscopy
is the carbon skeleton configuration;
sets the relative position of the C3F7 fragment respect to the peroxy
bond; 4(CF2ACF2AOAO) and u5 (CF2AOAOAN).
Four different minima are found in the PES being the one with
2 = 165°; 3 = 54°; 4 = 180° and 5 = 104°, the global minimum.
Fig. 4 shows the experimental (a) and calculated (b) infrared
spectra of C4F9OONO2. The infrared bands (in units of cmꢁ1), the
u
corresponding absorbance cross sections
(
r
ꢀ 1018 cm2 mole-
u
u
u
u
culeꢁ1, base e), and their assignment for the main peaks are:
1764 (3.51 0.07) mas (NO2), 1307 (1.63 0.04) ms (NO2), 1250
(3.36 0.07) mas (CF3), 1145 (1.76 0.04) mas (CꢁF), 894
These four minima are designated from 1 to 4 in ascending order of
their relative energy, as is shown in Table 1. Fig. 3 depicts the most
stable rotamer along with the numbering of atoms. A qualitative
inspection of the PES shows that inter-conversion between the
(0.72 0.03) ms (OꢁO), 789 (1.25 0.03) dNO2
. These are in
minima could involve trajectories needing less than 4 kcal molꢁ1
,
agreement with the general trend shown by many perfluoro alkyl
peroxynitrates (CxF2x+1OONO2, x = 1, 2, 3) [11,13,16], that show
rather narrow spans for the different IR bands as can be seen for
mas –NO2 (1764–1762 cmꢁ1), mas –CF3 (1244–1250 cmꢁ1), and dNO2
(789–792 cmꢁ1). A comparison between the experimental and
theoretical spectra shows a remarkable agreement, both in the rel-
ative intensities as well as in the position of the main peaks. Notice
that all the experimental bands have their calculated counterpart,
thus corroborating the identity of the new peroxynitrate.
As stated before, four different rotamers should be in equilib-
rium in a gas phase sample of CF3CF2CF2CF2OONO2 at room
temperature, according to the DFT calculation. Because of this,
the theoretical spectrum shown in the bottom of Fig. 4 was the
result of the linear combination of the theoretical spectrum of each
rotamer multiplied by the corresponding population. Every vibra-
tional transition was modeled with a Lorentzian function with
4 cmꢁ1 of FWHH. The comparison between the experimental and
theoretical spectra shows an excellent correlation for the featured
peaks.
and that the relative energies are less than 1.8 kcal molꢁ1 relative
to 1. Table 1 shows the B3LYP/6-311+G⁄ absolute and relative
energies together with the room temperature populations for the
rotamers along with their corresponding partition functions. Rela-
tive populations were calculated according to the formula
N1=Nx ¼ Q1=Qx ꢃ expðꢁ
D
E=kTÞ
ð6Þ
where Qx is the total partition function, taken from G09, of rotamer
x. The Qx values are calculated within the rigid-rotor/harmonic-
oscillator model and the contribution of internal rotational modes
are neglected. It is noteworthy that the calculation anticipates a
blend of the four rotamers at room temperature. This will be con-
firmed when analyzing the IR spectrum. Table 2 shows the geomet-
rical parameters for rotamer 1 together with values for C3F7OONO2
[11] calculated at the same level as well as the experimental GED
results of CF3OONO2 [14]. The CAOAOAN dihedral and the OAN
distance are the two most interesting parameters in peroxynitrates.
There is strong experimental evidence showing that the dihedral
XAOAOAY decreases from ꢂ120° when X and Y are sp3 hybridized
atoms to ꢂ105° when one is sp3 one sp2 and to ꢂ90° when both are
Table 3 shows the UV absorption cross sections determined in
our work for CF3CF2CF2CF2OONO2 from 200 to 282 nm, and their
comparison with data obtained from literature [11,15] for perflu-
oro alkyl peroxynitrates of shorter carbon chains, CxF2x+1OONO2
(x = 1, 3). The absorption cross sections were the average of five
spectra from samples ranging from 1.0 to 3.2 mbar that contained
the unavoidable small quantities of NO2, whose absorbances were
conveniently subtracted using the absorption cross sections rec-
ommended in Sander et al. [25].
hν
.
CF3CF2CF2CF2I
CF3CF2CF2CF2 + I
O2
NO2
.
CF3CF2CF2CF2OO
CF3CF2CF2CF2OONO2
.
RO2
I, NO
CF3CF2CF2CF2O
.
The comparison of the cross sections for the peroxynitrates cor-
roborates the general trend that shows a consistent decrease as the
length of the carbonated chain increases, probably as
consequence of the increment of the number of CF2 groups and
the concomitant increase in their withdrawing capacity.
a
.
CF3CF2CF2 + CF2O
O2
NO2
.
CF3CF2CF2OO
CF3CF2CF2OONO2
4.4. Thermal stability
Fig. 2. Reaction mechanism for the photolysis of CF3CF2CF2CF2I in the presence of
NO2 and O2. Products formed are marked in bold, and the new peroxynitrate formed
is highlighted.
The thermal stability of CF3CF2CF2CF2OONO2 was studied at dif-
ferent temperatures and total pressures, always in the presence of

14
A.G. Bossolasco et al. / Chemical Physics 441 (2014) 11–16
Table 1
B3LYP/6-311+G⁄ absolute energies plus ZPE, relative energies, partition function and room temperature populations for the different rotamers.
Conformer
Energy (Ha)
D
E (kcal/mol)
Q
Population
1
2
3
4
165-54-180-104
166-170-180-104
64-48-180-109
60-56-180-107
ꢁ1406.837801
ꢁ1406.836962
ꢁ1406.835759
ꢁ1406.835991
0
2.87 ꢅ 1021
3.01 ꢅ 1021
1.48 ꢅ 1021
1.75 ꢅ 1021
0.63
0.27
0.04
0.06
0.53
1.14
1.28
unavailability of proper data. The rate constants for reactions (2)
and (4) were assumed equal to those determined for
CF3CF2CF2CF2OOÅ radicals [29]. The rate constants reported and
the typical concentrations of NO2 and NO in our experiments pro-
vide a value of 1.04 for the bracketed term in Eq. (7), leading to a
correction of 4%. The values obtained for the rate constant k
,
ꢁ2
and its dependence with temperature and pressure, are presented
in Fig. 5. Temporal variation of CF3CF2CF2CF2OONO2 was monitored
using the peak at 1764 cmꢁ1. Errors bars included in the figure were
obtained from the fitting of the experimental data by linear
regression.
The Arrhenius plot was obtained at 9.0 mbar of total pressure
from 283 to 293 K. The kinetic parameters determined,
Ea = (81 4) kJ/mol and A = 3.2 ꢀ 1012 (Ln A = 29 2) for
CxF2x+1OONO2 (x = 4), as well as those taken from Mayer et al.
[13] (x = 1) and Bossolasco et al. [11,16] (x = 2, 3) allow the
comparison presented in Table 4. It can be observed a decrease
of both parameters as the length of the perfluorinated alkyl group
increases, in agreement with both, previous results [11] and
unimolecular reaction rate theories.
The C4F9OOANO2 bond rupture was studied with the UB3LYP/6-
311+G⁄ method evaluating the energy of the molecule when the
bond is elongated and the other parameters relaxed. The dissocia-
tion process was calculated evaluating the energy while increasing
the OOAN distance from 1.278 to 4.482 Å. The scan shows the typ-
ical energy surface of a simple fission process. A more detailed cal-
culation including the evaluation of vibrational frequencies from
3 Å gave a loose transition state at 3.145 Å of C4F9OOANO2 bond
length. The calculated activation energy found is 81.3 kJ molꢁ1 in
excellent agreement with the experimental value.
Fig. 3. Calculated structure for the most stable conformer of C4F9OONO2 (1).
NO to remove the CF3CF2CF2CF2OOÅ radicals thus allowing the
determination of the rate constant for the thermal decomposition.
The rate coefficients for reaction (-2) were corrected consider-
ing that, as time elapses, the NO added leads to an increase in
NO2 formation, slightly shifting the equilibrium toward the
formation of CF3CF2CF2OONO2 via reaction (2). The equation used
to correct the rate coefficient
ꢀ
ꢁ
k2 ½NO2ꢄ
k4 ½NOꢄ
k
¼ kOBS 1 þ
ð7Þ
ꢁ2
has been profusely used [26–28] even though in many cases it was
necessary to resort to values for similar entities because the
Kirchner et al. [3] have discussed structure–stability relation-
ships to estimate the thermal stability of peroxynitrates in terms
Table 2
Calculated geometric parameters of the most stable conformer.
Geometric parameters
C4F9OONO2
B3LYP6-311+G⁄
1.344
C3F7OONO2
B3LYP6-311+G⁄
1.343
CF3OONO2
GED
Distance (Å)
FAC (mean)
CAC (mean)
C5AO6
O6AO7
O7AN8
N8@O(9–10)
Angles (°)
FACAF
C2AC3AC4
C4AC5AO6
C5AO6AO7
O6AO7AN8
O7AN8@O9
O7AN8@O10
O9@N8@O10
C2AC3AC4AC5
C3AC4AC5AO6
C4AC5AO6AO7
C5AO6AO7AN8
O6AO7AN8AO10
O6AO7AN8AO9
Distance (Å)
FAC (mean)
CAC (mean)
C4AO5
O5AO6
O6AN7
N7@O(8–9)
Angles (°)
FACAF
C2AC3AC4
C5AC8AO11
C4AO5AO6
O5AO6AN7
O6AN7@O9
O6AN7@O8
O8@N7@O9
CAF
1.322
1.568
1.389
1.410
1.561
1.182
1.564
1.386
1.411
1.560
1.182
OAC
OAO
OAN
N@O
1.378
1.414
1.523
1.187
108.6
114.2
105.4
109.1
108.9
116.2
108.2
135.5
ꢁ166.6
ꢁ170.7
179.2
104.7
178.3
0.7
108.9
116.5
107.4
109.4
108.9
116.2
108.3
135.5
FACAF
108.8
OAOAC
OAOAN
107.7
108.4
O@N@O
135.2
C2AC3AC4AO5
C3AC4AO5AO6
C4AO5AO6AN7
O5AO6AN7AO8
O5AO6AN7AO9
ꢁ56.7
179.9
104.7
178.1
0.9
u
u
(CAOAOAN)
(OAOAN@O3)
105.1
178.3

A.G. Bossolasco et al. / Chemical Physics 441 (2014) 11–16
15
4
3
2
1
0
-4.5
4.0
3.8
3.6
3.4
3.2
3.0
2.8
(a)
-5.0
0
100
400
p2(0m0 bar3)00
-5.5
(b)
-6.0
3.40
3.45
3.50
3.55
(1/T) x 103 (K-1)
Fig. 5. Temperature dependence of the thermal decomposition of CF3CF2CF2CF2
OONO2 at 9.0 mbar of total pressure. The insert shows the dependence of the rate
constant with pressure.
2000
1800
1600
1400
1200
1000
800
-1
Table 4
ν (cm )
Kinetic parameters (Ea and A) of perfluoro alkyl peroxynitrates as a function of the
length of the carbon chain.
Fig. 4. (a) Experimental and (b) theoretical infrared spectra for
CF3CF2CF2CF2OONO2.
CF3OONO2
C2F5OONO2
C3F7OONO2
C4F9OONO2
Ea (kJ/mol)
A
90.8
87.7
84.9
81
4
1.05 ꢀ 1014
3.8 ꢀ 1013
1.0 ꢀ 1013
3.2 ꢀ 1012
of the electron density of the carbon atom attached to the AOONO2
group; the more electropositive this carbon atom the more stable
the OAN bond. We evaluated the electron density of the carbon
atom attached to the peroxide group as the Millikan population
obtaining +0.12 c.u. for C4F9OONO2 while for CF3OONO2 (calcu-
lated at the same level of theory) this value reaches +0.51 c.u., in
agreement with the dissociation activation energies shown in
Table 4.
The dependence of the rate constant with total pressure – from
9.0 to 417 mbar – plotted in the inset of Fig. 5, shows that it is more
pronounced at low pressures, but beyond 30 mbar its variation
falls within the experimental errors. Similar variations are
observed in the thermal decomposition of shorter perfluoro alkyl
peroxynitrates.
4.5. Atmospheric implications
The degradation of fluorinated compounds as n-CF3CF2CF2CF2H,
HFC-329p, leads to the formation of perfluorinated radicals, and
subsequently to the corresponding perfluoro alkyl peroxynitrates.
The thermal and photochemical lifetime from 0 to 50 km are
shown in Fig. 6. The comparison of thermal lifetime profiles for
CxF2x+1OONO2 calculated for x = 1 [13]; 2 [16]; 3 [11] and 4 (this
work), indicates that the thermal lifetime for x = 4 is the shortest,
in accordance with the activation energies for the series.
The photochemical lifetime profiles at 50° and 30° S are also
presented in Fig. 6. They were calculated using the TUV 4.2
Table 3
UV absorption cross sections for perfluoro alkyl peroxynitrates. Experimental errors are showed in brackets.
k (nm)
r
ꢀ 1020 (cm2 moleculeꢁ1
)
k (nm)
r
ꢀ 1020 (cm2 moleculeꢁ1
)
x = 1
x = 3
x = 4
x = 1
x = 3
x = 4
200
202
204
206
208
210
212
214
216
218
220
222
224
226
228
230
232
234
236
238
240
220 (10)
167
147
128
111
156 (4)
131 (3)
115 (3)
103 (2)
88 (2)
79 (2)
71 (2)
63 (1)
242
244
246
248
250
252
254
256
258
260
262
264
266
268
270
272
274
276
278
280
282
16.7
15.6
13.6
12.7
11.6
10.4
9.39
8.37
7.47
6.59
5.85
5.07
4.47
3.89
3.24
2.84
2.37
1.98
1.68
1.34
1.12
15.0 (0.3)
13.6 (0.3)
12.4 (0.3)
11.0 (0.2)
9.9 (0.2)
9.1 (0.2)
8.7 (0.2)
8.0 (0.2)
7.2 (0.2)
6.3 (0.2)
5.6 (0.2)
4.9 (0.2)
4.1 (0.1)
3.1 (0.1)
2.2 (0.1)
1.7 (0.1)
1.1 (0.1)
0.9 (0.1)
0.8 (0.1)
0.7 (0.1)
0.5 (0.1)
94.9
81.7
70.1
60.8
52.8
47.1
42.2
37.8
34.8
31.6
29.9
27.9
25.9
24.1
22.3
20.0
18.7
19 (1)
110 (10)
58 (4)
55 (1)
48 (1)
11.5 (0.8)
5.8 (0.6)
2.8 (0.5)
42.0 (0.8)
37.0 (0.7)
34.0 (0.7)
30.0 (0.6)
27.4 (0.6)
25.0 (0.5)
22.7 (0.5)
21.0 (0.5)
19.0 (0.5)
17.5 (0.5)
16.2 (0.5)
40 (2)
30 (1)

16
A.G. Bossolasco et al. / Chemical Physics 441 (2014) 11–16
Acknowledgments
40
30
20
10
0
Thermal lifetimes
C4F9OONO2
Photochemical lifetimes
-50º S
-30º S
Financial support from SECYT-Universidad Nacional de
Córdoba, ANPCyT, and CONICET is gratefully acknowledged. AGB
acknowledges the fellowship she holds from CONICET.
References
[1] R.K. Talukdar, J.B. Burkholder, A.M. Schmoltner, J.M. Roberts, R.R. Wilson, A.R.
Ravishankara, J. Geophys. Res. [Atmos.] 100 (1995) 163.
[2] F. Kirchner, L.P. Thuener, I. Barnes, K.H. Becker, B. Donner, F. Zabel, Environ. Sci.
Technol. 31 (1997) 1801.
[3] F. Kirchner, A. Mayer-Figge, F. Zabel, K.H. Becker, Int. J. Chem. Kinet. 31 (1999)
127.
[4] J.M. Roberts, PAN and related compounds, in: R. Koppmann (Ed.), Volatile
Organic Compounds in the Atmosphere, Blackwell Publishing Ltd., Oxford, UK,
2007.
[5] R.M. Ravelo, J.S. Francisco, J. Phys. Chem. A 112 (2008) 1981.
[6] C. Buendía-Atencio, V. Leyva, L. González, J. Phys. Chem. A 114 (2010) 9537.
[7] M.P. Badenes, L.B. Bracco, C.J. Cobos, J. Phys. Chem. A 115 (2011) 7744.
[8] R. Kopitzky, M. Beuleke, G. Balzer, H. Willner, Inorg. Chem. 36 (1997) 1994.
[9] M.P. Sulbaek Andersen, M.D. Hurley, T.J. Wallington, J.C. Ball, J.W. Martin, D.A.
Ellis, S.A. Mabury, O.J. Nielsen, Chem. Phys. Lett. 379 (2003) 28.
[10] M.P. Sulbaek Andersen, O.J. Nielsen, M.D. Hurley, J.C. Ball, T.J. Wallington, J.E.
Stevens, J.W. Martin, D.A. Ellis, S.A. Mabury, J. Phys. Chem. A 108 (2004) 5189.
[11] A.G. Bossolasco, F.E. Malanca, M.A. Burgos Paci, G.A. Argüello, J. Phys. Chem. A
116 (2012) 9904.
[12] C.J. Young, M.D. Hurley, T.J. Wallington, S.A. Mabury, Chem. Phys. Lett. 473
(2009) 251.
[13] A. Mayer-Figge, F. Zabel, K.H. Becker, J. Phys. Chem. 100 (1996) 6587.
[14] R. Kopitzky, H. Willner, H.G. Mack, A. Pfeiffer, H. Oberhammer, Inorg. Chem. 37
(1998) 6208.
[15] F.E. Malanca, M.S. Chiappero, G.A. Argüello, T.J. Wallington, Atmos. Environ. 39
(2005) 5051.
[16] A.G. Bossolasco, F.E. Malanca, G.A. Argüello, J. Photochem. Photobiol. A: Chem.
231 (2012) 45.
[17] O.N. Ventura, M. Kieninger, Chem. Phys. Lett. 245 (1995) 488.
[18] K. Raghavachari, B. Zhang, J.A. Pople, B.G. Johnson, P.M.W. Gill, Chem. Phys.
Lett. 220 (1994) 385.
[19] B.G. Johnson, C.A. Gonzalez, P.M.W. Gill, J.A. Pople, Chem. Phys. Lett. 221
(1994) 100.
[20] M.J. Frisch, G.W. Trucks, H.B. Schlegel, G.E. Scuseria, M.A. Robb, J.R. Cheeseman,
V.G. Zakrzewski, J.A. Montgomery Jr., R.E. Stratmann, J.C. Burant, S. Dapprich,
J.M. Millam, A.D. Daniels, K.N. Kudin, M.C. Strain, O. Farkas, J. Tomasi, V.
Barone, M. Cossi, R. Cammi, B. Mennucci, C. Pomelli, C. Adamo, S. Clifford, J.
Ochterski, G.A. Petersson, P.Y. Ayala, Q. Cui, K. Morokuma, D.K. Malick, A.D.
Rabuck, K. Raghavachari, J.B. Foresman, J. Cioslowski, J.V. Ortiz, A.G. Baboul,
B.B. Stefanov, G. Liu, A. Liashenko, P. Piskorz, I. Komaromi, R. Gomperts, R.L.
Martin, D.J. Fox, T. Keith, M.A. Al-Laham, C.Y. Peng, A. Nanayakkara, C.
Gonzalez, M. Challacombe, P.M.W. Gill, B. Johnson, W. Chen, M.W. Wong, J.L.
Andres, C. Gonzalez, M. Head-Gordon, E.S. Replogle, J.A. Pople, Gaussian 98,
Revision A.7, Gaussian Inc., Pittsburgh, PA, 1998.
[21] GaussView, Version 5, Roy Dennington, Todd Keith and John Millam,
Semichem Inc., Shawnee Mission, KS, 2009.
[22] J. Sehested, O.J. Nielsen, T.J. Wallington, Chem. Phys. Lett. 213 (1993) 457.
[23] C.E. Canosa-Mas, A. Vipond, R.P. Wayne, Phys. Chem. Chem. Phys. 1 (1999)
761.
0
50
100
150
200
τ
(days)
Fig. 6. Thermal and photochemical atmospheric lifetimes of C4F9OONO2. (—):
thermal. (—d—); photochemical at 50° and (—j—); photochemical at 30° south
latitude.
program [30] as a function of altitude and solar zenith angle.
The values presented are the result of the average for four
selected days; the solstices and the equinoxes.
independent quantum yield of unity at all wavelengths was
assumed.
Comparison between the lifetimes due to thermal and
photochemical processes for C4F9OONO2 indicates that the first
process controls the atmospheric lifetime. Though at ground level
the thermal lifetime is lower than 1 day, at altitudes of the free tro-
posphere it reaches values as long as three months. Beyond 15 km,
the photochemical rupture is the dominant process, with lifetime
values from 4 months at around 15 km to less than 1 day at alti-
tudes higher than 20 km.
A pressure
5. Conclusions
Synthesis and characterization of the new C4 perfluoro alkyl
peroxynitrate, and its comparison with shorter congeners was
performed. This allows an advance in the knowledge of
thermal stabilities and atmospheric lifetimes of perfluorinated
peroxynitrates that could be formed in the atmosphere on
account of the halocarbons (HCFCs, HFCs, HFEs) emitted to
the atmosphere.
From the study presented in this paper, it can be concluded that
the photochemical lifetime increases with the length of the
carbonated chain; while the thermal lifetime follows an opposite
behavior. The counteracting effect of these two processes, leads
finally to the atmospheric lifetimes of the CxF2x+1OONO2 family.
Thus, if present in the atmosphere, they should act as a reservoir
species of peroxy radicals and NO2, mainly in the lower
atmosphere.
[24] B. Casper, D.A. Dixon, H.-G. Mack, S.E. Ulic, H. Willner, H. Oberhammer, J. Am.
Chem. Soc. 116 (1994) 8317.
[25] S.P. Sander, R.R. Friedl, A.R. Ravishankara, D.M. Golden, C.E. Kolb, M.J. Kurylo,
R.E. Huie, V.L. Orkin, M.J. Molina, G.K. Moortgat, B.J. Finlayson-Pitts, Chemical
Kinetics and Photochemical Data for Use in Atmospheric Studies, Jet
Propulsion Laboratory, Pasadena, California, 2005.
[26] L.K. Christensen, T.J. Wallington, A. Guschin, M.D. Hurley, J. Phys. Chem. A 103
(1999) 4202.
[27] F. Zabel, F. Kirchner, K.H. Becker, Int. J. Chem. Kinet. 26 (1994) 827.
[28] J. Sehested, L.K. Christensen, O.J. Nielsen, M. Bilde, T.J. Wallington, W.F.
Schneider, J.J. Orlando, G.S. Tyndall, Int. J. Chem. Kinet. 30 (1998) 475.
[29] A.M.B. Giessing, A. Feilberg, T.E. Møgelberg, J. Sehested, M. Bilde, T.J.
Wallington, O.J. Nielsen, J. Phys. Chem. 100 (1996) 6572.
[30] S. Madronich, S. Flocke, The Role of Solar Radiation in Atmospheric Chemistry,
in: P. Boule (Ed.), Handbook of Environmental Chemistry, Springer, Heidelberg,
1998, pp. 1–26.
Conflict of interest
Thera are no conflict of interests.