Kr–Cl stretching vibration of HKrCl: Matrix-isolation and anharmonic ab initio study
The Kr–Cl stretching vibration of HKrCl molecule is studied. The absorption shows ³⁵Cl and ³⁷Cl isotopic splitting due to natural abundance of the Cl isotopes. The observed Kr–Cl stretching vibrations of the HKrCl are at 253.1 (³⁵Cl) and 248.3 cm–¹ (³⁷Cl). Deuteration of the HKrCl does not cause exp...
Gespeichert in:
| Datum: | 2003 |
|---|---|
| Hauptverfasser: | , , , , |
| Format: | Artikel |
| Sprache: | English |
| Veröffentlicht: |
Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України
2003
|
| Schriftenreihe: | Физика низких температур |
| Schlagworte: | |
| Online Zugang: | http://dspace.nbuv.gov.ua/handle/123456789/128937 |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| Назва журналу: | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| Zitieren: | Kr–Cl stretching vibration of HKrCl: Matrix-isolation and anharmonic ab initio study / Antti Lignell, Jan Lundell, Mika Pettersson, Leonid Khriachtchev, Markku Räsänen // Физика низких температур. — 2003. — Т. 29, № 9-10. — С. 1109-1112. — Бібліогр.: 23 назв. — англ. |
Institution
Digital Library of Periodicals of National Academy of Sciences of Ukraine| id |
irk-123456789-128937 |
|---|---|
| record_format |
dspace |
| spelling |
irk-123456789-1289372018-01-15T03:03:45Z Kr–Cl stretching vibration of HKrCl: Matrix-isolation and anharmonic ab initio study Lignell, Antti Lundell, Jan Pettersson, Mika Khriachtchev, Leonid Räsänen, Markku Spectroscopy in Cryocrystals and Matrices The Kr–Cl stretching vibration of HKrCl molecule is studied. The absorption shows ³⁵Cl and ³⁷Cl isotopic splitting due to natural abundance of the Cl isotopes. The observed Kr–Cl stretching vibrations of the HKrCl are at 253.1 (³⁵Cl) and 248.3 cm–¹ (³⁷Cl). Deuteration of the HKrCl does not cause experimentally a shift of the Kr–Cl stretching frequency. In addition to the Kr–Cl stretching mode, the bending mode of DKrCl is observed at 397.7 cm–¹. The vibrational analysis suggests that the Kr–Cl bond show, in addition to ionic, some covalent character. Anharmonic ab initio calculations are employed to verify vibrational properties of various isotopologues of HKrCl. 2003 Article Kr–Cl stretching vibration of HKrCl: Matrix-isolation and anharmonic ab initio study / Antti Lignell, Jan Lundell, Mika Pettersson, Leonid Khriachtchev, Markku Räsänen // Физика низких температур. — 2003. — Т. 29, № 9-10. — С. 1109-1112. — Бібліогр.: 23 назв. — англ. 0132-6414 PACS: 33.15.-e http://dspace.nbuv.gov.ua/handle/123456789/128937 en Физика низких температур Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України |
| institution |
Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| collection |
DSpace DC |
| language |
English |
| topic |
Spectroscopy in Cryocrystals and Matrices Spectroscopy in Cryocrystals and Matrices |
| spellingShingle |
Spectroscopy in Cryocrystals and Matrices Spectroscopy in Cryocrystals and Matrices Lignell, Antti Lundell, Jan Pettersson, Mika Khriachtchev, Leonid Räsänen, Markku Kr–Cl stretching vibration of HKrCl: Matrix-isolation and anharmonic ab initio study Физика низких температур |
| description |
The Kr–Cl stretching vibration of HKrCl molecule is studied. The absorption shows ³⁵Cl and ³⁷Cl isotopic splitting due to natural abundance of the Cl isotopes. The observed Kr–Cl stretching vibrations of the HKrCl are at 253.1 (³⁵Cl) and 248.3 cm–¹ (³⁷Cl). Deuteration of the HKrCl does not cause experimentally a shift of the Kr–Cl stretching frequency. In addition to the Kr–Cl stretching mode, the bending mode of DKrCl is observed at 397.7 cm–¹. The vibrational analysis suggests that the Kr–Cl bond show, in addition to ionic, some covalent character. Anharmonic ab initio calculations are employed to verify vibrational properties of various isotopologues of HKrCl. |
| format |
Article |
| author |
Lignell, Antti Lundell, Jan Pettersson, Mika Khriachtchev, Leonid Räsänen, Markku |
| author_facet |
Lignell, Antti Lundell, Jan Pettersson, Mika Khriachtchev, Leonid Räsänen, Markku |
| author_sort |
Lignell, Antti |
| title |
Kr–Cl stretching vibration of HKrCl: Matrix-isolation and anharmonic ab initio study |
| title_short |
Kr–Cl stretching vibration of HKrCl: Matrix-isolation and anharmonic ab initio study |
| title_full |
Kr–Cl stretching vibration of HKrCl: Matrix-isolation and anharmonic ab initio study |
| title_fullStr |
Kr–Cl stretching vibration of HKrCl: Matrix-isolation and anharmonic ab initio study |
| title_full_unstemmed |
Kr–Cl stretching vibration of HKrCl: Matrix-isolation and anharmonic ab initio study |
| title_sort |
kr–cl stretching vibration of hkrcl: matrix-isolation and anharmonic ab initio study |
| publisher |
Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України |
| publishDate |
2003 |
| topic_facet |
Spectroscopy in Cryocrystals and Matrices |
| url |
http://dspace.nbuv.gov.ua/handle/123456789/128937 |
| citation_txt |
Kr–Cl stretching vibration of HKrCl: Matrix-isolation and anharmonic ab initio study / Antti Lignell, Jan Lundell, Mika Pettersson, Leonid Khriachtchev, Markku Räsänen // Физика низких температур. — 2003. — Т. 29, № 9-10. — С. 1109-1112. — Бібліогр.: 23 назв. — англ. |
| series |
Физика низких температур |
| work_keys_str_mv |
AT lignellantti krclstretchingvibrationofhkrclmatrixisolationandanharmonicabinitiostudy AT lundelljan krclstretchingvibrationofhkrclmatrixisolationandanharmonicabinitiostudy AT petterssonmika krclstretchingvibrationofhkrclmatrixisolationandanharmonicabinitiostudy AT khriachtchevleonid krclstretchingvibrationofhkrclmatrixisolationandanharmonicabinitiostudy AT rasanenmarkku krclstretchingvibrationofhkrclmatrixisolationandanharmonicabinitiostudy |
| first_indexed |
2025-07-09T10:15:50Z |
| last_indexed |
2025-07-09T10:15:50Z |
| _version_ |
1837164033582563328 |
| fulltext |
Fizika Nizkikh Temperatur, 2003, v. 29, Nos. 9/10, p. 1109–1112
Kr–Cl stretching vibration of HKrCl: Matrix-isolation and
anharmonic ab initio study
Antti Lignell, Jan Lundell*, Mika Pettersson, Leonid Khriachtchev,
and Markku Räsänen
Laboratory of Physical Chemistry, University of Helsinki, P.O. Box 55, FIN-00014, Finland
E-mail: lignell@csc.fi
The Kr–Cl stretching vibration of HKrCl molecule is studied. The absorption shows 35Cl and
37Cl isotopic splitting due to natural abundance of the Cl isotopes. The observed Kr–Cl stretching
vibrations of the HKrCl are at 253.1 (35Cl) and 248.3 cm–1 (37Cl). Deuteration of the HKrCl does
not cause experimentally a shift of the Kr–Cl stretching frequency. In addition to the Kr–Cl
stretching mode, the bending mode of DKrCl is observed at 397.7 cm–1. The vibrational analysis
suggests that the Kr–Cl bond show, in addition to ionic, some covalent character. Anharmonic ab
initio calculations are employed to verify vibrational properties of various isotopologues of
HKrCl.
PACS: 33.15.–e
1. Introduction
A number of hydrogen-containing rare gas mole-
cules HRgY (H is hydrogen, Rg is a rare gas atom,
and Y is an electronegative fragment) have been syn-
thesized and studied in low-temperature matrices
within the last several years [1,2]. Preparation of
these HRgY molecules consists of photodecomposition
of the HY precursor followed by thermal mobilization
of atomic hydrogen in a low-temperature rare gas ma-
trix. Infrared absorption spectroscopy is a useful
method for detecting these molecules due to the large
intensity of the H–Rg stretching vibration absorption
[2]. In addition to the H–Rg stretching modes, bend-
ing vibrations for many of the HRgY molecules have
been observed. The heavy-atom stretching vibration
modes �(Rg–Y) have been observed only for HArF
and HKrF [3–5]. The indirect observation of the Xe–I
stretching frequency of HXeI, calculated as a differ-
ence between combination and fundamental vibration,
has been previously reported [6]. Since there are a va-
riety of Rg–Y bonds in these HRgY compounds, it
would be very interesting to learn more about the na-
ture of the bonding via direct observation of the Rg–Y
stretching vibration. In this work, we study experi-
mentally and computationally the Kr–Cl stretching
modes of the H/D and 35Cl/37Cl isotopologues of
HKrCl. The experimental data is compared with our
previous experimental measurements for HKrF [5].
2. Experimental and computational details
In the HCl/Kr experiments, HCl (99%, CIL) and
Kr (99.995% Aga) gases were mixed in a glass bulb.
The gas mixture was deposited onto a CsI window
kept at 27 K in a closed-cycle helium cryostat (APD,
DE 202A). The typical matrix thickness after the
30-minute deposition was 100–200 µm. Deuteration of
HCl was achieved by passing premixed gas over the
deuterated sulphuric acid (>99% D2, Merck) in the
deposition line. The resulting HCl/DCl ratio was
typically �1. The samples were photolysed through a
MgF2 window at 7.5 K by an 193 nm ArF-excimer la-
ser (MPB, MSX-250) using �104 pulses with a pulse
energy density of �10 mJ/cm2. The infrared (IR)
spectra were measured with a Nicolet SX 60 FTIR
spectrometer. In the mid-IR spectral region, the spec-
trometer was operated with a Ge–KBr beam split-
ter (BS) and a MCT detector and resolutions of 0.25
and 1 cm–1 were used, while in the far-IR region
(< 400 cm–1) a 6 µm mylar BS with a DTGS detector
and 1 cm–1 resolution were used.
In the computational description of the potential
energy surface of HKrCl, electron correlation was
© Antti Lignell, Jan Lundell, Mika Pettersson, Leonid Khriachtchev, and Markku Räsänen, 2003
* Permanent address: eChemicum (Chemistry ICT-center), University of Helsinki, P.O. Box 55, FIN-00014, Finland
considered via Møller-Plesset perturbation theory to
the second order (MP2), and all electrons were ac-
counted for in the calculations (MP2 = FULL). The
correlation consistent double-zeta quality all-electron
basis set, aug-cc-pVDZ, was employed for all atoms.
The equilibrium structure and harmonic vibrational
frequencies of HKrCl were also studied by the
higher-level coupled cluster [CCSD(T)] approach.
The anharmonic vibrational frequencies were obtained
from the vibrational self-consistent field (VSCF) and
its extension by corrections via second-order perturba-
tion theory (CC-VSCF) [7–10]. A pairwise coupling
approximation was made to the potential in the nor-
mal mode representation [8]. Further details of
CC-VSCF combined with an ab initio electronic
structure code are given in Refs. 9 and 10. All ab ini-
tio calculations at the MP2 and CC-VSCF levels were
performed in the framework of the GAMESS elec-
tronic structure program on dual PIII/500MHz work-
stations [11]. The CCSD(T) calculations were per-
formed on a SGI Origin 2000 computer at the
CSC-Center for Scientific Computing Ltd. (Espoo,
Finland) using the «Gaussian 98» package of pro-
grams [12].
3. Experimental results
The HCl/Kr samples were highly monomeric with
respect to HCl and DCl precursors and the known ab-
sorption bands of HCl at 2872.9 and 2870.5 cm–1, and
DCl at 2078.6 and 2075.6 cm–1 dominate in the spec-
tra [13]. A small amount of HCl and DCl was
complexed with N2 due to natural nitrogen impurity
in the matrices. Interestingly, the complexation effi-
ciency of DCl was observed to be significantly higher
than that of HCl. Typically, >90% of HCl was decom-
posed upon 193 nm photolysis, and the decomposition
of DCl was somewhat slower than that of HCl.
HKrCl and DKrCl appeared already during pho-
tolysis as reported previously [14]. Annealing of the
sample at � 30 K led to an increase of the amount of
HKrCl and DKrCl due to mobilization of atomic hy-
drogen in a Kr matrix [15]. The observed H–Kr
stretching (1476.1 cm–1, see Fig. 1) and H–Kr–Cl
bending vibration bands (543.7 and 542.1 cm–1 with
the overtone at 1069.3 and 1067.9 cm–1) are in a good
agreement with the previous experimental data [1].
The Kr–Cl stretching vibrations of HKrCl were
observed at 253.1 and 248.3 cm–1, the splitting
(4.8 cm–1) being due to the natural 35Cl and 37Cl iso-
topes (see Fig. 1). The intensity ratio between the
HKr35Cl and HKr37Cl bands is � 3.2 in accordance
with the natural isotope ratio of 3.1. In addition to the
previously reported band of the D–Kr stretching mode
of DKrCl at 1105.6 cm–1 [1], the D–Kr–Cl bending
vibration band was found at 397.7 cm–1, which is the
new spectroscopic data obtained here. The Kr–Cl
stretching vibrations of DKrCl were practically un-
shifted from the corresponding HKrCl bands (see
Fig. 1). The experimental assignment of the Kr–Cl
stretching bands of HKrCl and DKrCl are based on
the following arguments. They increase synchronously
with the known HKrCl and DKrCl bands upon an-
nealing. Photostability of the bands are similar as
1110 Fizika Nizkikh Temperatur, 2003, v. 29, Nos. 9/10
Antti Lignell, Jan Lundell, Mika Pettersson, Leonid Khriachtchev, and Markku Räsänen
1550 1500 300 250 200
0
0.2
0.4
1150 1100 300 250 200
0.1
0.2
a
*
37Cl
35Cl
X 2
� (Kr–Cl)� (H–Kr)
Wavenumber, cm–1
Wavenumber, cm–1
b
*
37
Cl
35Cl
X 2
� (Kr–Cl)� (D–Kr)
A
b
so
rb
a
n
ce
, a
rb
. u
n
its
A
b
so
rb
a
n
ce
, a
rb
. u
n
its
Fig. 1. FTIR spectra of HKrCl (a) and DKrCl (b) in the
middle and far infrared regions. 35Cl/37Cl isotopes cause
a splitting (4.8 cm–1) of the bands in the Kr–Cl stretch-
ing vibration mode. A band marked with asterisk belongs
to N2 complex of HKrCl and DKrCl (see Ref. 23) induced
by small nitrogen impurity present in the matrix. In plot
(b), the bands of HKrCl are subtracted.
checked with ArF-excimer laser (193 nm). The
35Cl/37Cl isotopic shift and intensity ratio show
proper values. Finally, the computations (see later)
agree with the observed experimental findings.
4. Computational results and discussions
The optimized H–Kr and Kr–Cl bond distances
of the linear HKrCl molecule, calculated at the
MP2/aug-cc-pVDZ computational level, are 1.500
and 2.563 Å, respectively. The harmonic vibrational
frequencies obtained at this computational level are
1943.1, 604.2, and 275.7 cm–1. The increase of elec-
tron correlation to the CCSD(T) level gives longer
H–Kr and Kr–Cl distances of 1.545 and 2.580 Å, re-
spectively, and the frequency of H–Kr stretching
mode shifts down to 1512.8 cm–1, which is close to the
experimentally observed H–Kr stretching frequency
(1476.1 cm–1). Increasing the electron correlation af-
fects less the bending and Kr–Cl stretching modes. At
the CCSD(T) level of theory the predicted frequen-
cies are at 569.9 and 273.0 cm–1, respectively, which
are very similar to the values obtained using the MP2
calculations.
The high-level harmonic calculations neglect an-
harmonicity of the potential energy surfaces. How-
ever, there is experimental and theoretical evidence
for important anharmonic effects for HRgY molecules
[6,16–18]. The anharmonic MP2 vibrational frequen-
cies of the HKrCl isotopologues are shown in Table.
The H–Kr stretching (�3) is predicted at 1691.0 cm–1,
� 250 cm–1 below the corresponding harmonic value.
Clearly, both electron correlation and anharmonicity
are important for the adequate description of this mo-
lecule. The H–Kr–Cl bending (�2) and Kr–Cl stretch-
ing (�1) modes appear to be less anharmonic than the
H–Kr stretching. In the anharmonic calculations, the
bending vibration mode is reduced to 575.2 cm–1, i.e.,
� 30 cm–1 below its harmonic value. The �(Kr–Cl)
mode is relatively insensitive to the inclusion of
anharmonicity and the vibration is predicted to be at
274.3 cm–1, shifted only by +1.4 cm–1 from the har-
monic prediction.
The computational overtone spectrum of HKrCl is
rather rich and several bands are predicted to be prom-
ising for experimental detection. The experimentally
observed first overtone of the H–Kr–Cl bending mode
offers a good benchmark for the anharmonic calcula-
tions. The first overtone is predicted to lie at
1149.8 cm–1 whereas the experimentally observed
overtone is at 1069.4 cm–1 [1]. Computationally the
infrared intensity of the first overtone is 10% from its
fundamental intensity whereas the experimental value
is � 30%. The first and second overtones of the H–Kr
stretching mode and the first overtone of the Kr–Cl
stretch are predicted to be intense enough to be exper-
imentally searched for, however, they were not ob-
served in this work experimentally.
The HRgY molecules have (HRg)+Y– ion-pair cha-
racter. The stronger electronegative moiety Y– causes
Kr–Cl stretching vibration of HKrCl: Matrix-isolation and anharmonic ab initio study
Fizika Nizkikh Temperatur, 2003, v. 29, Nos. 9/10 1111
Table
Anharmonic computational (MP2/CC-VSCF) and experimental frequencies (in cm–1) of HKrCl and its isotopologues.
The computational IR intensities (in km/mol) calculated at HF level are given in parentheses. The experimental IR
intensities are in arbitrary units
Level
HKr35Cl
Computational
HKr37Cl
Computational
Åõðerimental
DKr35Cl
Computational
DKr37Cl
Computational
Åõðerimental
3�
3
4627.2 (1.0) 4627.1 (1.0) – 3496.9 (0.2) 3496.8 (0.2) –
2�
3
3207.1 (3.9) 3207.0 (3.9) – 2410.1 (1.2) 2410.0 (1.2) –
3�
2
1723.7 (0.4) 1723.3 (0.4) – 1267.6 (0.1) 1267.0 (0.1) –
�
3
�(H–Kr) 1691.0 (680.9) 1691.0 (681.3) 1476.1 (1.00) 1250.9 (351.6) 1250.8 (352.1) 1105.6 (1.00)
2�
2
1149.8 (3.3) 1149.5 (3.3) 1069.4,1067.9 (0.01) 844.1 (1.0) 843.7 (1.0) –
3�
�
817.3 (0.0) 801.7 (0.0) – 817.0 (0.0) 801.4 (0.0) –
�
2
�(H–Kr–CI) 575.2 (33.1) 575.0 (33.3) 543.7, 542.1 (0.03) 421.6 (13.3) 421.4 (13.5) 397.7 (0.02)
2�
�
546.7 (1.1) 536.3 (1.1) – 546.5 (1.1) 536.0 (1.0) –
�
1
�(Kr–CI) 274.3 (137.7) 269.0 (132.4) 253.1 (0.05) 35Cl 274.2 (137.1) 268.9 (131.9) 253.1 (0.17) 35Cl
248.3 (0.05) 37Cl 248.3 (0.17) 37Cl
larger charge separation between the (HRg)+ and Y–
moieties shortening the H–Rg distance and enhancing
its vibrational frequency. This leads to stronger cova-
lent bonding of the (HRg)+ entity, while covalent
character of the Rg–Y bond is reduced lowering the
activation energy of dissociation via bending motion.
According to the experimental data, the quadratic
force constant (f2) for Kr–Cl stretch of HKrCl is
0.93 N/cm as calculated from equation f c2
2 2 24� � � �,
where � is the vibrational wavenumber, c is the light
velocity, and µ is the reduced mass. For comparison,
f2 for Kr–F stretch of HKrF is 1.57 N/cm [5], and the
force constants for asymmetric stretches of KrF2 and
XeCl2 are 2.59 N/cm and 1.32 N/cm [19,20], respec-
tively. These data indicate a stronger Kr–F chemical
bonding than Kr–Cl bonding in accordance with the
electron localization studies of Berski and co-workers
[21]. Similar trend can be seen for the H–Kr moiety
when its covalent character is enhanced from HKrCl
to HKrF as judged by the increase of the H–Kr
stretching frequency. As a reference, the harmonic
wavenumbers for the Kr+Cl– and Kr+F– exciplexes are
(208 20) and (284 27) cm–1 deduced from their elec-
tronic emission spectrum [22], resulting in force con-
stants of f2(Kr+Cl–) = 0.63 N/cm and f2(Kr+F–) =
= 0.74 N/cm. Since the exciplexes are ionic in nature,
the higher frequency of the Kr–Y stretch in HKrY
molecules suggest that the Kr–Y bonding in HKrY
molecules is not purely ionic but contains also some
covalent contribution between the Kr and Y frag-
ments. The covalent contribution between Rg–Y frag-
ments is essential for the existence of a bending barrier
in HRgY molecules and thus important for the intrin-
sic stability of HRgY molecules.
5. Conclusions
The Kr–Cl stretching vibration mode for various
isotopologues of HKrCl is studied experimentally and
compared with the previous measurements on the
Kr–F stretching mode of HKrF. Anharmonic vibra-
tional calculations are done on the HKrCl molecule
and show good argeement with the experiments. Ac-
cording to the vibrational analysis, it is suggested that
the Kr–Cl and Kr–F bonds of HKrCl and HKrF mole-
cules have, in addition to ionic, some covalent contri-
butions.
Acknowledgment
Ministry of Education, Finland supported this
work. The CSC-Center for Scientific Computing Ltd.
(Espoo, Finland) is thanked for providing excellent
computer facilities. A.L. is a member of the graduate
school LASKEMO (Academy of Finland).
1. M. Pettersson, J. Lundell, and M. Räsänen, J. Chem.
Phys. 102, 6423 (1995).
2. J. Lundell, L. Khriachtchev, M. Pettersson, and M. Rä-
sänen, Fiz. Nizk. Temp. 26, 923 (2000) [Low Temp.
Phys. 26, 680 (2000)].
3. L. Khriachtchev, M. Pettersson, N. Runeberg, J. Lun-
dell, and M. Räsänen, Nature (London) 406, 874 (2000).
4. L. Khriachtchev, M. Pettersson, A. Lignell, and
M. Räsänen, J. Am. Chem. Soc. 123, 8610 (2001).
5. M. Pettersson, L. Khriachtchev, A. Lignell, M. Rä-
sänen, Z. Bihary, and R. B. Gerber, J. Chem. Phys.
116, 2508 (2002).
6. J. Lundell, M. Pettersson, L. Khriachtchev, M. Rä-
sänen, G.M. Chaban, and R.B. Gerber, Chem. Phys.
Lett. 322, 389 (2000).
7. J.O. Jung and R.B. Gerber, J. Chem. Phys. 105,
10332 (1996).
8. J.O. Jung and R.B. Gerber, J. Chem. Phys. 105,
10682 (1996).
9. G.M. Chaban, J.O. Jung, and R.B. Gerber, J. Chem.
Phys. 111, 1823 (1999).
10. G.M. Chaban, J.O. Jung, and R.B. Gerber, J. Phys.
Chem. A104, 2772 (2000).
11. M.W. Schmidt, K.K. Baldridge, J.A. Boatz et al., J.
Comput. Chem. 14, 1347 (1993).
12. M. J. Frisch, G. W. Trucks, H. B. Schlegel et al.,
Gaussian 98, Rev. A.11.4, Gaussian Inc., Pittsburgh
PA (2002).
13. M.T. Bowers and W.H. Flygare, J. Chem. Phys. 44,
1389 (1966); L.F. Keyser and G.W. Robinson, J. Chem.
Phys. 44, 3225 (1966); D.E. Mann, N. Acquista, and
D. White, J. Chem. Phys. 44, 3453 (1966).
14. L. Khriachtchev, M. Pettersson, J. Lundell, and M. Rä-
sänen, J. Chem. Phys. 114, 7727 (2001).
15. K. Vaskonen, J. Eloranta, T. Kiljunen, and H. Kunt-
tu, J. Chem. Phys. 110, 2122 (1999).
16. J. Lundell, G.M. Chaban, and R.B. Gerber, J. Phys.
Chem. A104, 7944 (2000).
17. M. Pettersson, J. Lundell, and M. Rasanen, Eur. J.
Inorg. Chem. 729 (1999).
18. L. Khriachtchev, J. Lundell, M. Pettersson, H. Tans-
kanen, and M. Räsänen, J. Chem. Phys. 116, 4758
(2002).
19. C. Murchison, S. Reichman, D. Anderson, J. Overend,
and F. Schreiner, J. Am. Chem. Soc. 90, 5690 (1968).
20. L.Y. Nelson and G.C. Pimentel, Inorg. Chem. 6, 1758
(1967).
21. S. Berski, B. Silvi, J. Lundell, S. Noury, and Z. La-
tajka in: New Trends in Quantum Systems in Che-
mistry and Physics, Vol. 1, J. Maruani, C. Minot, R.
McWeeny, Y.G. Smeyers, and S. Wilson (eds.), Klu-
wer Academic Publishers, Dordrecht (2001), p. 259.
22. M. F. Golde, Mol. Spectrosc. 58, 261 (1975).
23. A. Lignell, L. Khriachtchev, M. Pettersson, and M. Rä-
sänen, J. Chem. Phys. 117, 961 (2002).
1112 Fizika Nizkikh Temperatur, 2003, v. 29, Nos. 9/10
Antti Lignell, Jan Lundell, Mika Pettersson, Leonid Khriachtchev, and Markku Räsänen
|