Constants for Radicals: Polyatomic Free Radicals

555 Pages·2005·4.374 MB·English

by  W. Hüttner (auth.), W. Hüttner (eds.)

1 Introduction 1
1 Introduction
1.1 General remarks
The present volume II/24 (published as five sub volumes II/24A, II/24B, II/24C, II/24D, and II/24E) is a
supplement to and an extension of volume II/19 published in 1992-1994 and has been prepared on the
understanding that it will be used in combination with II/4, II/6, II/14 and II/19. The reader will find
helpful remarks on how to use the data listings, especially the definitions of the molecular constants, in
front of each table.
Volume II/24 presents the spectroscopic data on diamagnetic and paramagnetic molecules as well as
on molecular ions. For the diamagnetic species the publications up to the year of 1997 are included. The
sub volumes for the paramagnetic species have been published later and cover the literature up to 2001.
The spectroscopic information collected in this volume has been obtained principally from gas phase
microwave measurements. In addition, gas phase data have been included derived from methods related
to microwave spectroscopy by employing a coherent radiation source. These are molecular beam
techniques, radio frequency spectroscopy, electron resonance spectroscopy, laser spectroscopy, double
resonance and saturation techniques. Some other methods are considered if the accuracy of the derived
molecular parameters is comparable to that of microwave spectroscopy owing to a good statistics in the
analysis of data, and no microwave data are available. Examples would be Fourier infrared spectroscopy
or laser induced fluorescence.
Internuclear distances are listed in the tables only for diatomic molecules and for some small open
shell molecules. For all other polyatomic molecules the literature giving structural information has been
cited.
A new comprehensive compilation of structural data is published in volume II/25 of the New Series of
Landolt-Börnstein.
1.2 Review articles and tables
Some books treating recent developments in microwave spectroscopy are listed in 1.8, [1-7].
The Journal of Physical and Chemical Reference Data has published a series of tables of line
frequencies, absorption intensities and molecular constants for diatomic [8], triatomic [9], selected
polyatomic molecules and for molecules of particular interest in astrophysics. Some species of radicalic
and ionic character are also included. The series started in 1972 and is continuing [10].
Since 1973 the Chemical Society (London) has regularly published a review on microwave spectros-
copy [11].
Molecular constants from infrared spectroscopic data are currently published in Landolt-Börnstein
New Series in volume II/20.
1.3 Arrangement of tables, substances and parameters
1.3.1 Arrangement of chapters and sections
The arrangement of data in Vols. II/4, II/6, and II/14 and II/19 is retained as far as possible. The data of
molecules is listed in chapters 2 and 3.
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2 1 Introduction
In sections 2.2 through 2.5 the diamagnetic molecules are ordered according to the type of their
respective spectrum as follows: Diatomic molecules (2.2), linear molecules (2.3), symmetric top
molecules (2.4), and asymmetric top molecules (2.5). Molecules which are asymmetric only due to
isotopic substitution are listed together with their parent species in 2.4. The tables include rotational
constants, centrifugal distortion constants, rotation-vibration interaction constants, and (cid:34)-type doubling
constants. Some additional molecular constants obtained by microwave type methods have been listed as
well. References to publications concerning the molecular structure are cited separately.
Tables 2.6 through 2.9 contain the dipole moments (2.6), nuclear quadrupole coupling constants (2.7),
constants of hindered rotation (2.8) and magnetic interaction constants (2.9) of the molecules.
The literature used for chapter 2 is contained in separate sections of chapter 2 where for the reader's
convenience the page where to find the appropriate reference section is indicated at the top of each page
of the tables. The references are ordered according to the publication year followed by the three letters of
the first author's name and in few cases by an additional running number. For each year the references are
ordered alphabetically.
Chapter 3 contains the diatomic radicals (3.1) and the polyatomic radicals (3.2), where a radical is
strictly defined here as a paramagnetic molecule. In chapter 3 the references are collected separately for
each molecule.
The index of substances is provided in chapter 4, and terminates volume II/24. Chapters 2.1…2.4 are
contained in the sub volume II/24A. Chapter 2.5 is presented in sub volume II/24B. Chapters 2.6…2.9 are
given in sub volume II/24C. Chapter 3.2 is contained in the present sub volume II/24D2, chapter 3.1 will
appear in II/24D1. Chapter 4 will be published in sub volume II/24E.
1.3.2 Arrangement within the sections of chapters 2 and 3
The arrangement of the columns within the sections of chapters 2 and 3 is similar to that in the previous
volumes. The explanation of the symbols used in the tables is found under the subsection “Preliminary
remarks” for each individual table. The ordering of the diamagnetic substances in each table of chapter 2
follows the early suggestion of Hill [12]. This means that the molecules are arranged in alphabetical order
of the element symbols - with the exception of carbon and hydrogen atoms in organic compounds which
are written first in that order. In this way, all organic substances are bound together between sum
formulas starting with Br (if present) and those starting with Ca (if present). Deuterium is treated like
hydrogen.
A typical series of substances according to Hill's system would be AlF , BCl , …, B H , CBrN, CFN,
3 3 2 6
CHCl , CH Cl , …, CIN, C H, …, ClF .
3 2 2 2 5
Note that the tables of diamagnetic molecules in the volumes II/4, II/6, and II/14, were organized in a
different way.
The radicals (chapter 3) are not ordered strictly by Hill’s system.
In this volume II/24, the ions are not collected separately but are included in the tables like the neutral
molecules.
1.3.3 Explanation of the columns of the tables in chapters 2 and 3
In chapter 2, column 1 gives the running number of each molecule in the table. The numbers in the
corresponding table of Vols. II/4, II/6, II/14, and II/19 are given below the running number.
Column 2 gives the structural formula of the molecule. The isotopic species are labeled with the
isotopic numbers with the exception of the most abundant species, where the labels have been omitted. C
=12C, O =16O,S = 32S, N = 14N, etc.
The vibrational state of the molecule for which the listed constants were obtained is added (not in
tables 2.9.2 and 2.9.3).
The next columns contain the values of the constants with which the table is concerned, and their
references. Where several references are given, the first reference listed is the publication from which the
numerical values were taken.
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1 Introduction 3
The last column of each table contains general remarks and values if necessary. This column also
gives references to tables or diagrams which contain further information on the respective molecule. In
tables 2.2 through 2.5 references are given in this column to all following tables and chapters. In tables
2.6 through 2.9 references are given only to tables 2.2 through 2.5. Thus all information given for each
molecule may be reliably found by the use of tables 2.2 through 2.5.
In chapter 3, the complete set of molecular constants is collected often in front or behind a listing of
reliable experimental transition frequencies separately for each species. Radicals require greatly differing
angular momentum coupling schemes and therefore different kinds of effective hamiltonians for fitting
spectra. Consequently, in contrast to chapter 2, the tabulations in chapter 3 show generally more
individual character per molecule.
1.3.4 Notation of experimental errors
The error in a tabulated value is written as defined by the following equations (examples taken from LB.
NS, Vol.II/7):
53479.72(25) cm(cid:237)1 = (53479.72 ± 0.25) cm(cid:237)1
9.4(48) cm(cid:237)1 = (9.4 ± 4.8) cm(cid:237)1
153.7754(13) pm = (153.7754 ± 0.0013) pm
Evidently the error given in parentheses on the left side applies to the last significant digits. According to
international usage this notation normally indicates one standard deviation in molecular spectroscopy.
Deviations thereof, if known from the literature, are specified in the tables.
1.4 Selection of data
For a molecule which was studied by several authors, the data of those authors are listed whose work (a)
was the most complete (comparison of the data of a particular molecule), (b) was the most recent and (c)
appeared to be the most accurate one. The work of other authors is cited in the references, but only the
most recent paper of a particular research group is usually given. Data from dissertations and conference
research reports were only included when no other publication could be located.
1.5 Abbreviations used for experimental methods
BMS beam maser spectroscopy
EPR electron paramagnetic resonance
FIR far infrared spectroscopy
IR infrared spectroscopy with or without laser
IRIRDR infrared-infrared double resonance
IRMWDR infrared-microwave double resonance
La laser
LaSt laser Stark spectroscopy
LC level crossing spectroscopy
LIF laser induced fluorescence
LMR laser magnetic resonance
LRMW low resolution microwave spectroscopy
MB molecular beam electric/ magnetic resonance (sometimes for the state preparation
and detection lasers are used)
MBE molecular beam electric resonance
MBM molecular beam magnetic resonance
MBRF molecular beam radiofrequeney spectroscopy
MBMW molecular beam microwave and mm-wave spectroscopy
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4 1 Introduction
MODR microwave optical double resonance
MOMRIE microwave optical magnetic resonance induced by electrons
MW microwave spectroscopy in the cm- and mm-wavelength region
OS optical spectroscopy
QB quantum beat spectroscopy
RFODR radio frequency optical double resonance
RFIRDR radio frequency infrared double resonance
RFMWDR radio frequency microwave double resonance
SLS saturated laser spectroscopy
Additional experimental techniques are indicated in the tables if necessary.
1.6 Selected fundamental constants and energy conversion factors
The determination of molecular constants from the measured frequencies of spectral lines needs best
values of the fundamental constants. The “best values” improve with advancing techniques of
measurement and changes in valuation. The recommended values listed in the following table are based
on the publication by Mohr and Taylor [13].
Recommended physical constants
Quantity Symbol Value Units
SI cgs
Speed of light c 2.99792458 (exact) 108 m s(cid:237)1 1010cm s(cid:237)1
Fine structure constant (cid:302) 7.297352533 (27) 10(cid:237)3 10-3
(cid:302)(cid:237)1 137.03599976 (50)
Electron charge e 1.602176426(63) 10(cid:237)19C 10(cid:237)20emu
4.803206 (15) 10-10esu
Planck's constant h 6.62606876 (52) 10(cid:237)34 J s 10(cid:237)27erg⋅s
(cid:33)= h/2(cid:652) 1.054571596 (82) 10(cid:237)34J⋅s 10(cid:237)27 erg⋅s
Avogadro's number NA 6.02214199 (47) 1023 mol(cid:237)1 1023 mol(cid:237)1
Atomic mass unit1) mu=1 u 1.66053873 (13) 10(cid:237)27 kg 10(cid:237)24g
Proton rest mass m 1.67262158 (13) 10(cid:237)27 kg 10(cid:237)24 g
p
Neutron rest mass m 1.67492716 (13) 10(cid:237)27 kg 10(cid:237)24 g
n
Rydberg constant R 1.0973731568549 (83) 107 m(cid:237)1 105 cm(cid:237)1
∞
Bohr radius a 5.291772083 (19) 10(cid:237)11 m 10(cid:237)9cm
0
Bohr magneton µ 9.27400899 (37) 10(cid:237)24J T(cid:237)1 10(cid:237)21 erg Gauss(cid:237)1
B
Nuclear magneton µ 5.05078317 (20) 10(cid:237)27 J T(cid:237)1 10(cid:237)24erg Gauss(cid:237)1
N
Electron magnetic moment2) µ 9.28476362 (37) 10(cid:237)24J T(cid:237)1 10(cid:237)21erg Gauss(cid:237)1
e
Electron magnetic moment µ/µ 1.0011596521869 (41)
e B
in Bohr magnetons 2)
Proton magnetic moment2) µ 1.410606633 (58) 10(cid:237)26J T(cid:237)1 10(cid:237)23 erg Gauss(cid:237)1
p
1) The atomic mass unit is sometimes called 1 amu (= 1 m (12C) = 1.6605402 (10)⋅10(cid:237)27kg).
12
2) The modulus (length) of the vector is given (the direction is related to that of the spin, which is antiparallel for the
electron and parallel for the proton).
These values yield the conversion factor I ·B relating rotational constant to moment of inertia:
I · B= 5.05379006 (65) 105amu Å2 MHz.
Note that authors may have used slightly variant values in their original work which is normally not
corrected in the tables.
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1 Introduction 5
The following table for conversion between different energy scales may be used (uncertainties are all
about 3 ppm, if needed, more accurate values may be calculated from the preceding table):
Energy conversion factors
J erg eV cm(cid:237)1 cal Hz
J 1 107 6.24151 ⋅ 1018 5.03411 ⋅ 1022 2.39006 ⋅ 10(cid:237)1 1.50919 ⋅ 1033
erg 10(cid:237)7 1 6.24151 ⋅ 1011 5.03411 ⋅ 1015 2.39006 ⋅ 10(cid:237)8 1.50919 ⋅ 1026
eV 1.60218 ⋅ 10(cid:237)19 1.60218 ⋅ 10(cid:237)12 1 8065.54 3.82931 ⋅ 10(cid:237)20 2.41799 ⋅ 1014
cm(cid:237)1 1.98645 ⋅ 10(cid:237)23 1.98645 ⋅ 10(cid:237)16 1.23984 ⋅ 10(cid:237)4 1 4.74763 ⋅ 10(cid:237)24 2.99792 ⋅ 1010
cal 4.18400 4.18400 ⋅ 107 2.61144 ⋅ 1019 2.10631 ⋅ 1023 1 6.31445 · 1033
Hz 6.62607 ⋅ 10(cid:237)34 6.62607 ⋅ 10(cid:237)27 4.13567 ⋅ 10(cid:237)15 3 33565 ⋅ 10(cid:237)11 1.58367 ⋅ 10(cid:237)34 1
1.8 References for 1
1 Gordy, W., Cook, R.L.: Microwave Molecular Spectra, New York: John Wiley & Sons, 1984.
2 Buckingham, A. D.: MTP International Review of Science. Physical Chemistry, Series 2, Vol. 2:
Molecular Structure and Properties, London: Butterworths, 1975.
3 Buckingham, A.D., Ramsay, D.A.: MTP International Review of Science. Physical Chemistry,
Series 2, Vol. 3: Spectroscopy, London: Butterworths, 1976.
4 Chantry, G. W.: Modern Aspects of Microwave Spectroscopy, London: Academic Press, 1979.
5 Kroto, H.W.:Molecular Rotation Spectra, New York: John Wiley and Sons, 1975.
6 Lide, D. R., Paul, M.A.: Critical Evaluation of Chemical and Physical Structural Information,
Washington, D.C.: National Academy of Sciences, 1974.
7 Rao, K. N.: Molecular Spectroscopy, Modern Research, Vol. II, New York: Academic Press, 1976.
8 Lovas, F.J.: J. Phys. Chem. Ref. Data 3(1974) 609.
9 Lovas, F.J.: J. Phys. Chem. Ref. Data 7 (1978) 1445.
10 Lovas, F.J.: J. Phys. Chem. Ref.Data 33 (2004) 177.
11 Molecular Spectroscopy. Specialist Periodical Reports. The Chemical Society, London. Vol. 1
(1973), Vol. 2 (1974), Vol. 3 (1975): Barrow, R.F., Long, D.A., Millen, D.J. (eds.); Vol. 4 (1976),
Vol. 5 (1978), Vol. 6 (1979): Barrow, R.F., Long, D.A., Sheridan, J. (eds.).
12 Hill, E. A.: J. Am. Chem. Soc. 22 (1900) 478.
13 Mohr, P. J., Taylor, B. N.: CODATA Recommended Values of the Fundamental Physical
Constants 1998: J. Phys. Chem. Ref. Data 28 Nr. 6 (1999) and Rev. Mod. Phys. 72 Nr.2 (2000)
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3.2.0 Introduction 1
3.2 Polyatomic radicals
3.2.0 Introduction
A radical is defined to be a molecule in an open shell electronic state. It is often, although not necessarily,
very reactive and short-lived in a laboratory environment. Several new species have been studied since
the publication of the previous supplement. Many of the new observations have been made by radio
astronomers who now have access to frequencies up to 500 GHz. Experiments employing double
resonance techniques (simultaneous irradiation with microwaves and either infrared or visible radiation)
have also made a contribution to the development of the field. The information about linear molecules, in
2(cid:520), 3(cid:520), and 2(cid:518) states, is contained in section 3.2.1. The non-linear radicals, almost all of which are
triatomic, are presented in 3.2.2 (Symmetric molecules), 3.2.3 (Non-linear triatomic molecules), and 3.2.4
(Non-linear larger molecules).
Data which relate to molecular rotational energy levels have been fitted to the parameters of an
appropriate effective Hamiltonian. Such a Hamiltonian must take account of all the many interactions
which can arise for a molecule in a multiplet electronic state. The foundations for many of the features of
this model have been securely laid by Van Vleck [51Van] with an important contribution for linear
triatomic molecules in (cid:518) states (the Renner-Teller effect) having been made by Renner [34Ren]. There
have been many subsequent papers dealing with different aspects of the effective Hamiltonian, some of
which are listed in the previous supplement. For a good overall description, the reader is referred (still) to
the third volume of Herzberg's book “Molecular Spectra and Molecular Structure” [66Her]. The effects of
centrifugal distortion on the rotational energy levels, depending on their formulation, may cause
indeterminacies among the parameters in the Hamiltonian. Watson [67Wat, 77Wat] has shown how these
indeterminacies can be systemically removed. Watson's ideas about the expression of the effective
Hamiltonian in terms of determinable parameters have been extended to the spin-rotation Hamiltonian
and its centrifugal distortion corrections by Brown and Sears [79Bro]. A concise treatment of the various
terms in the Hamiltonian, together with expressions for their matrix elements has been published by
Hirota [85Hir].
Values for the inertial defect and the electric dipole moment quoted in this section have been
recalculated where necessary using the currently accepted values for Planck's constant, Avogadro's
number and the experimental value for the dipole moment µ of 16O12C32S. The first two of these are
h = 6.62606876(52) ·10(cid:237)34 Js and N = 6.02214199(47) ·1023 mol(cid:237)1 [99Moh]. The best determination of
A
µ available to date is that by Lahaye, Vandenhaute and Fayt [86Lah] whose value is 0.7151887(26)D.
ocs
The value for the speed of light is now defined to be c = 2.99792458 · 108ms(cid:237)1 [93Mi1]. The rotational
constant times moment of inertia product on the 12Cbasis is thus
B · I= 5.05379006(65) 105 MHz amu Å2≡ 16.8576291(22) amu Å2 cm(cid:237)1.
References
34Ren Renner, R.: Z. Phys. 92 (1934) 172.
51Van Van Vleck, J. H.: Rev. Mod.Phys. 23 (1951) 213.
66Her Herzberg, G.: Molecular Spectra and Molecular Structure III. Electronic Spectra and Electronic
Structure of Polyatomic Molecules, New York: Van Nostrand Reinhold Company, 1966.
67Wat Watson, J.K.G.: J. Chem. Phys. 46 (1967) 1935.
77Wat Watson, J.K.G.: Aspects of Quartic and Sextic Centrifugal Effects on Rotational Energy Levels,
in: Vibrational Spectra and Structure, Vol. 6 (Durig, J.R., ed.), Amsterdam: Elsevier, 1977.
79Bro Brown, J. M., Sears, T. J.: J. Mol. Spectrosc. 75 (1979) 111.
85Hir Hirota, E.: High Resolution Spectroscopy of Transient Molecules, New York, Berlin, Heidel-
berg: Springer-Verlag, 1985.
86Lah Lahaye, J.G., Vandenhaute, R., Fayt, A.: J. Mol. Spectrosc. 119 (1986) 267.
93Mi1 Mills, I. M., Cvitaš, T., Homann, K., Kallay, N., Kuchitsu, K.: Quantities, Units and Symbols
in Physical Chemistry, IUPAC, Oxford: Blackwell Scientific Publications, 1993.
99Moh Mohr, P.J., Taylor, B.N:CODATA Recommended Values of the Fundamental Physical
Constants 1998: J. Phys. Chem. Ref. Data 28 Nr. 6 (1999) and Rev. Mod. Phys. 72 Nr.2 (2000)
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3.2.1.1 Linear polyatomic radicals: Preliminary remarks 1
3.2.1 Linear polyatomic radicals
3.2.1.1 Preliminary remarks
1 Introduction
The rotational spectra of linear polyatomic molecules are very similar to those of diatomic molecules in
the same electronic state. The reader is therefore referred to chapter 3.1 for additional information. Data
are included here for molecules in 2(cid:520), 3(cid:520), and 2(cid:518) states only. In the former two cases, the description of
the energy levels is identical to that for the corresponding diatomic molecule (except that there are more
vibrational modes). In the latter case, the situation is made more complicated by the interaction between
electron orbital and vibrational angular momenta, known as the Renner-Teller effect [34Ren, 66Her]. For
a triatomic molecule, the effect involves the bending vibration ν and the coupling leads to a pattern of
2
vibronic energy levels which have been described in many other places e.g. [66Her] and are labeled by
the vibronic quantum number K(= (cid:513) + (cid:34)) rather than the individual orbital and vibrational quantum
numbers. There have been significant developments in the theoretical description of the vibronic energy
levels over the past few years [80Jun, 82Bro] but the details of this work fall outside the scope of the
present compilation.
The data reported for the molecules in the 2(cid:520), 3(cid:520), and 2(cid:518) states have been analysed in terms of an
effective Hamiltonian which refers to the rotational, spin and hyperfine levels of a particular vibronic
state. The Hamiltonian is formulated in terms of the various angular momenta involved, namely, N,L,S,
G, J, I, and F which are respectively the rotational, orbital, electron spin, vibrational, nuclear plus
electronic, nuclear spin, and total angular momenta (strictly speaking, N = R + Lwhere R is the angular
momentum of the nuclear framework). The effective Hamiltonian can be written
H = H + H + H + H + H + H + H + H .
eff rot so ss sr cd LD hfs Q
The terms on the right hand side refer to the rotational kinetic energy, the spin-orbit interaction, the
spin-spin interaction, the spin-rotation interaction, centrifugal distortion effects, lambda-type doubling,
the magnetic nuclear hyperfine interactions and the electric quadrupole coupling term. They have been
described in detail elsewhere (see Section 3.1.5 and refs. [62Hou], [78Bro], [79Bro1]). Two alternative
formulations can be found in the literature, one in terms of R2 [70Hou] and the other in terms of N2
[79Bro1]. The two approaches give identical results for a given data set except that the parameter values
are slightly different. Interconversion between the two parameter sets is straightforward [87Bro]. For
molecules in (cid:518) electronic states, subject to the Renner-Teller effect, special considerations may be
required in treating the various terms in H . Hougen has discussed the rotational Hamiltonian, H from
eff rot,
this point of view [62Hou] and Russell and Beaudet have considered the magnetic hyperfine interactions
[74Rus]. A general formulation of the lambda doubling terms has been given by Brown and Merer
[79Bro2]:
( ) ( )
( )
H =1o S2 +S2 −1 p N S +N S + 1q N2 +N2
LD 2 υ + − 2 υ + + − − 2 υ + −
where ov, pv, and qv are the lambda-doubling parameters for the vibrational level (cid:547), S± = Sx ± iSy and
N± = Nx ± iNy, and the operators are defined on the implicit understanding that they link the (cid:513) = 1 and
(cid:513) = (cid:237)1 components of the (cid:518) state only. The parameters can be related in turn to the electronic properties
of the molecule.
The nuclear spin magnetic hyperfine interactions are represented by
Hhfs = aIzLz+ bFI· S +13 c(3IzSz-I ·S)(cid:237) 12 d(S+ I++S− I−)
where a, b , c, and d are the four hyperfine parameters [52Fro, 78Bro] and the angular momentum
F
operators are as defined above. The four terms describe the nuclear spin-orbit, the Fermi contact, the
dipolar and the lambda doubling (dipolar) interactions respectively. Frosch and Foley [52Fro] originally
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2 3.2.1.1 Linear polyatomic radicals: Preliminary remarks
formulated the Hamiltonian in terms of a slightly different parameter b, dependent on both the Fermi
contact and dipolar interactions:
b=b (cid:237) 1 c.
F 3
In many cases, the parameter pair b and c is better determined by the data than b and c even though
F
the latter might be considered to have more physical significance. For molecules in 2(cid:520) and 3(cid:520) states, the
magnetic nuclear hyperfine effects can be described in terms of two parameters only, b and c (or bandc,
F
if preferred). The magnetic hyperfine parameters give information on the spatial distribution of the open
shell electrons [88Ste, 90Ama].
The nuclear electric quadrupole interactions are represented by
eQq ( ) eQq ( )
H = 0 3I2−I2 + 2 I2+I2
Q 4I(2I−1) z 8I(2I−1) + −
where eQ is the nuclear quadrupole moment and q and q are the electric field gradients parallel and
0 2
perpendicular to the linear axis respectively [78 Bro]. The second term only shows a first order effect in (cid:518)
states.
2 List of tabulated parameters
B rotational constant for the molecule in a particular vibrational level. The subscript (cid:547) has
been omitted in the tables because the vibrational or vibronic states are indicated separately
D,H centrifugal distortion constants for a given vibrational level
A spin orbit coupling constant for a given vibrational level
AD centrifugal distortion to spin-orbit coupling
(cid:534) spin rotation coupling constant for a given vibrational level
(cid:534)D centrifugal distortion to spin-rotation coupling
λ electron spin dipolar coupling parameter for a given vibrational level
λD centrifugal distortion of electron spin diplar coupling parameter
o, p, q lambda-type doubling parameters
oD, pD, qD,
oH,pH,qH centrifugal distortion to lambda-type doubling parameters
a, b, c, d, b nuclear spin magnetic hyperfine parameters
F
h , h
1/2 3/2
(or h ,h ) combinations of magnetic hyperfine parameters in 2Π states: h = a + (b+c)/2, h = a –
1 2 1/2 3/2
(b+c)/2
eQqo, eQq2 nuclear electric quadrupole coupling constants ((cid:507)(cid:513) = 0 and ±2 terms respectively)
µ electric dipole moment
(cid:441)2 harmonic frequency for the bending vibration (ν2)
q,qN (or qD), (cid:400) – type doubling constant and centrifugal corrections in vibrationally excited degenerate
qNN(or qH) states, see Vol. II/24A. Note that q is also in use for one of the lamda-type doubling
parameters above
(cid:304) Renner-Teller coupling parameter
V0,V0,V0,V2 coefficients in the intermolecular potential between OH and the Ar atom in the van der
1 2 3 2
Waals’ complex, Ar…OH
3 List of symbols used
X(cid:5) 2(cid:166),X(cid:5) 2Π designation of 2(cid:520) or 2(cid:518) electronic ground states
2(cid:518),2(cid:507),2Φ designation of vibronic states with K = 1, 2 or 3
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3.2.1.1 Linear polyatomic radicals: Preliminary remarks 3
v ,v v vibrational quantum numbers for the three normal modes of a linear triatomic molecule
1 2, 3
Mode number 2 is always associated with the bending vibration
(cid:513) quantum number associated with component of orbital angular momentum L along
internuclear axis
(cid:400),(cid:520) corresponding quantum numbers for the components of the vibrational (G) and spin (S)
angular momenta along internuclear axis
K vibronic quantum number, valid in the presence of a strong Renner-Teller effect. Defined
K=(cid:513)+(cid:400)
(cid:923)(2(cid:520)), µ(2(cid:520)) upper((cid:923)) and lower(µ) vibronic K=0 sublevels in a 2(cid:518) electronic state [62Hou]
e, f designation of parity. States with parity(−1)J−12 are labelled e, those with parity -(−1)J−12 are
labeled f [75Bro]
u, l label for the upper and lower components of a parity doublet, in the situation where the
parity is not known.
4 Arrangement of substances
1. C H 13. C H 25. HC N 37. SrOH
2 14 6
2. C H 14. CCN 26. HCCP 38. BaOH
3
3. C H 15. C N 27. HCCS 39. MgCN
4 3
4. C H 16. C N 28. HC S 40. MgNC
5 5 3
5. C H 17. CCO 29. HC S 41. CaNC
6 4
6. C H 18. C O 30. SiCN 42. MgC H
7 4 2
7. C H 19. C O 31. SiNC 43. CaC H
8 6 2
8. C H 20. C O 32. SiCCH 44. SrC H
9 8 2
9. C H 21. CCS 33. NaCH 45. ArOH
10
10. C H 22. C S 34. KCH 46. ArSH
11 4
11. C H 23. HCCN 35. MgOH 47. FeCO
12
12. C H 24. HC N 36. CaOH
13 4
5 References
34Ren Renner. R.: Z. Phys. 92 (1934) 172.
52Fro Frosch, R. A., Foley, M. M.: Phys. Rev. 88 (1952) 1337.
62Hou Hougen, J.T.: J. Chem. Phys. 36 (1962) 519.
66Her Herzberg, G.: Molecular Spectra and Molecular Structure 111. Electronic Spectra and
Electronic Structure of Polyatomic Molecules, New York: Van Nostrand Reinhold Company,
1966.
70Hou Hougen, J.T.:The Calculation of Rotational Energy Levels and Rotational Line Intensities in
Diatomic Molecules, Natl. Bur. Stand. Monogr. 115 (1970).
74Rus Russell, D. K., Beaudet, R. A.: Mol. Phys. 27 (1974) 1645.
75Bro Brown, J.M., Hougen, J.T., Huber, K.-P., Johns, J.W.C., Kopp, I., LeFebvre-Brion, H.,
Merer, A. J., Ramsay, D. A., Rostas, J., Zare, R. N.: J. Mol. Spectrosc. 55 (1975) 500
78Bro Brown, J. M., Kopp, I., Malmberg, C., Rydh, B.: Phys. Scri. 17 (1978) 55.
79Bro1 Brown, J. M., Colbourn, E. A., Watson, J. K. G., Wayne, F. D.: J. Mol. Spectrosc. 74 (1979)
294.
79Bro2 Brown, J. M., Merer, A. J.: J. Mol. Spectrosc. 74 (1979) 488.
80Jun Jungen, Ch., Merer, A. J.: Mol. Phys. 40 (1980) 1.
82Bro Brown, J. M., Jørgensen, F.: Adv. Chem. Phys. 52 (1982) 117.
87Bro Brown, J. M., Cheung, A. S.-C., Merer, A. J.: J. Mol. Spectrosc. 124 (1987) 464.
88Ste Steimle, T. C., Chang, W. L., Nachman, D.F.,Brown, J. M.: J. Chem. Phys. 89 (1988) 7172.
90Ama Amano, T.: J. Mol. Spectrosc. 144 (1990) 454.
Landolt-Börnstein
New Series II/24D2
3.2.1 Linear polyatomic radicals 1
3.2.1.2.1 CH
2
Microwave data for 12C12C1H
Transition
rotational fine hyperfine a) ν
N′ – N″ J′ – J″ F′ – F″ [MHz] Ref.
~
X2Σ+
State: electronic ; vibrational (0,0,0)
1← 0 11 ← 1 1← 1 87 284.156(30) b) 83Go
2 2
2← 1 87 316.925(4)
1← 0 87 328.624(6)
1 ← 1 1← 1 87 402.004(5)
2 2
0← 1 87 407.165(11)
1← 0 87 446.512(23)
2← 1 21 ← 11 3← 2 174 663.222(8)
2 2
2← 1 174 667.685(17)
11 ← 1 2← 1 174 721.777(26)
2 2
1← 0 174 728.074(30)
3← 2 31 ← 21 4← 3 262 004.260(50) 81Sa
2 2
3← 2 262 006.482(50)
21 ← 11 3← 2 262 064.986(50)
2 2
2← 1 262 067.469(50)
7← 6 71 ← 61 c) 611 267.201(80) 00Mü
2 2
61 ← 51 c) 611 329.708(80)
2 2
8← 7 81 ← 71 c) 698 544.778(150)
2 2
71 ← 61 c) 698 607.457(100)
2 2
9← 8 91 ← 81 c) 785 802.090(120)
2 2
81 ← 71 c) 785 864.969(120)
2 2
10 ← 9 101 ← 91 c) 873 036.391(80)
2 2
91 ← 81 c) 873 099.537(150)
2 2
11 ← 10 111 ← 101 c) 960 245.718(120)
2 2
101 ← 91 c) 960 308.867(120)
2 2
a) Coupling scheme: J = N + S ; F = J + I where I is the 1H nuclear spin
b) The figures in parentheses are the authors’ estimates of experimental uncertainty, in units of the last quoted decimal
place.
c) Proton hyperfine structure not resolved.
Molecular parameters for 12C12C1H
Parametera) Value Method Ref.
~
X2Σ+
State: electronic ; vibrational (0,0,0)
B [MHz] 43 674.528 94(115) b) MW 00Mü
D [MHz] 0.105 687(51)
H [Hz] 0.32(32)
γ [MHz] – 62.602 9(43)
γ [kHz] – 2.313(255)
D
b(1H) [MHz] 44.492 2(183)
F
bD(1H) [MHz] – 0.011 0(38)
F
c(1H) [MHz] 12.225 6(261)
a) The parameter values in this table supersede those of Gottlieb et al. [83 Go], given in L-B II/12 D.
b) The numbers in parentheses are 1 standard deviation of the least-squares fit, in units of the last quoted decimal place.
Landolt-Börnstein
New Series II/24D2