Dipotassium
- Formula: K2
- Molecular weight: 78.1966
- IUPAC Standard InChI: InChI=1S/2K
- IUPAC Standard InChIKey: ZDHURYWHEBEGHO-UHFFFAOYSA-N
- CAS Registry Number: 25681-80-5
- Chemical structure:
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Gas phase ion energetics data
Go To: Top, Constants of diatomic molecules, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data evaluated as indicated in comments:
L - Sharon G. Lias
Data compiled as indicated in comments:
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
B - John E. Bartmess
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| IE (evaluated) | 4.062 ± 0.0015 | eV | N/A | N/A | L |
Electron affinity determinations
| EA (eV) | Method | Reference | Comment |
|---|---|---|---|
| 0.497 ± 0.012 | LPES | Eaton, Sarkas, et al., 1992 | Vertical Detachment Energy: 0.550±0.010 eV.; B |
| 0.493 ± 0.012 | LPES | McHugh, Eaton, et al., 1989 | Vertical Detachment Energy: 0.550±0.010 eV; B |
Ionization energy determinations
| IE (eV) | Method | Reference | Comment |
|---|---|---|---|
| 4.0637 ± 0.0002 | PI | Kappes, Radi, et al., 1985 | LBLHLM |
| 4.0637 ± 0.0003 | PI | Broyer, Chevaleyre, et al., 1985 | LBLHLM |
| 4.06075 ± 0.00015 | LS | Leutwyler, Hofmann, et al., 1981 | LLK |
| 4.059 ± 0.001 | LS | Herrmann, Schumacher, et al., 1978 | LLK |
| 4.0607 ± 0.0001 | PI | Herrmann, Schumacher, et al., 1978 | LLK |
| 4.05 ± 0.05 | PI | Herrmann, Schumacher, et al., 1978 | LLK |
| 4.059 ± 0.001 | PI | Herrmann, Leutwyler, et al., 1978 | LLK |
| 3.9 | EI | Zmbov, Wu, et al., 1977 | LLK |
| 4.0 ± 0.1 | PI | Foster, Leckenby, et al., 1969 | RDSH |
| ~4.1 | S | Robertson and Barrow, 1961 | RDSH |
Appearance energy determinations
| Ion | AE (eV) | Other Products | Method | Reference | Comment |
|---|---|---|---|---|---|
| K+ | 4.85 | K | PI | Herrmann, Leutwyler, et al., 1978 | LLK |
Constants of diatomic molecules
Go To: Top, Gas phase ion energetics data, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled by: Klaus P. Huber and Gerhard H. Herzberg
Data collected through January, 1977
| Symbol | Meaning |
|---|---|
| State | electronic state and / or symmetry symbol |
| Te | minimum electronic energy (cm-1) |
| ωe | vibrational constant – first term (cm-1) |
| ωexe | vibrational constant – second term (cm-1) |
| ωeye | vibrational constant – third term (cm-1) |
| Be | rotational constant in equilibrium position (cm-1) |
| αe | rotational constant – first term (cm-1) |
| γe | rotation-vibration interaction constant (cm-1) |
| De | centrifugal distortion constant (cm-1) |
| βe | rotational constant – first term, centrifugal force (cm-1) |
| re | internuclear distance (Å) |
| Trans. | observed transition(s) corresponding to electronic state |
| ν00 | position of 0-0 band (units noted in table) |
| State | Te | ωe | ωexe | ωeye | Be | αe | γe | De | βe | re | Trans. | ν00 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Unidentified diffuse emission bands, 17460 - 17840 cm-1. | ||||||||||||
| ↳Rebbeck and Vaughan, 1971 | ||||||||||||
| Diffuse bands close to lines of the principal series of K; fragments of additional systems. | ||||||||||||
| ↳Kuhn, 1932; Chakraborti, 1937; Okuda, 1936 | ||||||||||||
| G | 28091 | 64.90 1 H | 0.55 | G ← X R | 28077 H | |||||||
| ↳Yoshinaga, 1937 | ||||||||||||
| F | 27571 | 62.29 1 H | 0.24 | F ← X R | 27556 H | |||||||
| ↳Yoshinaga, 1937 | ||||||||||||
| State | Te | ωe | ωexe | ωeye | Be | αe | γe | De | βe | re | Trans. | ν00 |
| E | 26494.0 | 61.8 2 H | 0.28 | E ← X R | 26478.9 H | |||||||
| ↳Yoshinaga, 1937; Sinha, 1950 | ||||||||||||
| D | 24627.7 | 61.60 H | 0.90 3 | 0.0010 | D ← X R | 24612.3 H | ||||||
| ↳Sinha, 1948 | ||||||||||||
| C 1Πu | 22969.43 | 61.485 Z | 0.133 | 0.04404 | 0.00011 | 3E-6 | 4.433 | C ← X R | 22954.20 Z | |||
| ↳Yamamoto, 1929; Sinha, 1948; Robertson and Barrow, 1961 | ||||||||||||
| B 1Πu | 15376.74 | 75.00 | 0.3876 4 | 4.366E-3 | 0.048763 5 | 0.00024 | 8.25E-8 | 4.2125 | B 6 ↔ X 7 R | 15368.20 Z | ||
| ↳Loomis, 1931; Loomis and Nusbaum, 1932; Tango, Link, et al., 1968 | ||||||||||||
| State | Te | ωe | ωexe | ωeye | Be | αe | γe | De | βe | re | Trans. | ν00 |
| A 1Σu+ | 11681.9 | 69.09 H | 0.153 | 8 | A ↔ X R | 11670.5 H | ||||||
| ↳Crane and Christy, 1930; Sorokin and Lankard, 1971 | ||||||||||||
| a 3Σu+ | Not observed; scattering calculations predict a very shallow potential minimum at ~8.7 Å. | |||||||||||
| ↳Geittner, 1975 | ||||||||||||
| X 1Σg+ | 0 | 92.021 Z | 0.2829 9 | -2.055E-3 | 0.056743 | 0.000165 10 | 8.63E-8 | 3.9051 11 | ||||
| ↳Kusch, Millman, et al., 1939; Logan, Cote, et al., 1952; Brooks, Anderson, et al., 1963 | ||||||||||||
Notes
| 1 | Analysis by Yoshinaga, 1937; not confirmed by Sinha, 1950. |
| 2 | Average of the constants obtained by Yoshinaga, 1937, Sinha, 1950. |
| 3 | ωeze = -0.00030; convergence at 25590. |
| 4 | ωeze = -0.0001830; vibrational constants for v'≤ 25 from low-resolution magnetic rotation spectra. Higher vibrational levels converge rapidly at 17160 cm-1 above X 1Σg+, v=0. Te is from the analysis of high-resolution laser-induced fluorescence spectra Tango, Link, et al., 1968. |
| 5 | Recalculated by Tango, Link, et al., 1968, from the data of Loomis, 1931. |
| 6 | Radiative lifetime τ(v = 6,7,8) = 12.4 ns Tango and Zare, 1970; Baumgartner, Demtroder, et al., 1970 measured 9.7 ns. |
| 7 | Absorption cross sections Lapp and Harris, 1966. |
| 8 | A complex magnetic rotation spectrum has been observed which may be due to perturbations of A 1Σu+ by an unidentified 3Π state Carroll, 1937. |
| 9 | Vibrational and rotational constants from the laser-induced B ≥ X fluorescence spectrum Tango, Link, et al., 1968. |
| 10 | αv= -7.2E-6(v+1/2)2 + 1.5E-7(v+1/2)3. See 9. |
| 11 | Mol. beam magn. reson. 14 |
| 12 | From the convergence limit of B 1Πu. Thermochemical value [ Lewis, 1931, recalculated Loomis and Nusbaum, 1932] 0.56 eV. |
| 13 | Photoionization of K2 Foster, Leckenby, et al., 1969; in agreement with limits (3.57 ≤ I.P. ≤ 4.11 eV) obtained from chemi-ionization thresholds Lee and Mahan, 1965, Williams, 1967, Robertson and Barrow, 1961 estimate 4.09 eV. |
| 14 | gJ = 0.02163 μN Brooks, Anderson, et al., 1963. For NMR spectrum and potassium eqQ see Kusch, Millman, et al., 1939, Logan, Cote, et al., 1952. |
| 15 | From D00(K2) + I.P.(K) - I.P.(K2). The experimentally observed limits (photoionization of potassium vapor, are 0.74 eV ≤ D00 ≤ 1.27 eV Williams, 1967. Theoretical calculations Bellomonte, Cavaliere, et al., 1974 give l eV. |
| 16 | Theoretical calculations Bellomonte, Cavaliere, et al., 1974. |
References
Go To: Top, Gas phase ion energetics data, Constants of diatomic molecules, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Eaton, Sarkas, et al., 1992
Eaton, J.G.; Sarkas, H.W.; Arnold, S.T.; Mchugh, K.M.; Bowen, K.H.,
Negative Ion Photoelectron Spectroscopy of the Heteronuclear Alkali-Metal Dimer and Trimer Anions - NaK-, KRb-, RbCS-, KCs-, Na2K-, and K2Cs,
Chem. Phys. Lett., 1992, 193, 1-3, 141, https://doi.org/10.1016/0009-2614(92)85697-9
. [all data]
McHugh, Eaton, et al., 1989
McHugh, K.M.; Eaton, J.G.; Lee, G.H.; Sarkas, H.W.; Kidder, L.H.; Snodgrass, J.T.; Manaa, M.R.; Bowen, K.H.,
Photoelectron Spectra of the alkali metal cluster Anions: Na-,n=2-5, K-,n=2-7, Rb-,n=2-3, and Cs-,n=2-3,
J. Chem. Phys., 1989, 91, 6, 3792, https://doi.org/10.1063/1.456861
. [all data]
Kappes, Radi, et al., 1985
Kappes, M.M.; Radi, P.; Schar, M.; Schumacher, E.,
Photoionization measurements on dialkali monohalides generated in supersonic nozzle beams,
Chem. Phys. Lett., 1985, 113, 243. [all data]
Broyer, Chevaleyre, et al., 1985
Broyer, M.; Chevaleyre, J.; Delacretaz, G.; Fayet, P.; Woste, L.,
One- and two-photon ionization of alkaline clusters,
Surf. Sci., 1985, 156, 342. [all data]
Leutwyler, Hofmann, et al., 1981
Leutwyler, S.; Hofmann, M.; Harri, H.-P.; Schumacher, E.,
The adiabatic ionization potentials of the alkali dimers Na2, NaK and K2,
Chem. Phys. Lett., 1981, 77, 257. [all data]
Herrmann, Schumacher, et al., 1978
Herrmann, A.; Schumacher, E.; Woste, L.,
Preparation and photoionization potentials of molecules of sodium, potassium and mixed atoms,
J. Chem. Phys., 1978, 68, 2327. [all data]
Herrmann, Leutwyler, et al., 1978
Herrmann, A.; Leutwyler, S.; Schumacher, E.; Woste, L.,
38. On metal-atom clusters IV. Photoionization thresholds and multiphoton ionization spectra of alkali-metal molecules,
Helv. Chim. Acta, 1978, 61, 453. [all data]
Zmbov, Wu, et al., 1977
Zmbov, K.F.; Wu, C.H.; Ihle, H.R.,
A mass spectrometric study of heteronuclear diatomic alkali metal molecules. Dissociation energies ionization potentials of NaLi, KLi, NaK,
J. Chem. Phys., 1977, 67, 4603. [all data]
Foster, Leckenby, et al., 1969
Foster, P.J.; Leckenby, R.E.; Robbins, E.J.,
The ionization potentials of clustered alkali metal atoms,
J. Phys. B:, 1969, 2, 478. [all data]
Robertson and Barrow, 1961
Robertson, E.W.; Barrow, R.F.,
Rotational analysis oi the C1πu-X1+g system of K2, and the ionisation potential of K2,
Proc. Chem. Soc., 1961, 329. [all data]
Rebbeck and Vaughan, 1971
Rebbeck, M.M.; Vaughan, J.M.,
Unidentified diffuse bands in the spectrum of potassium,
J. Phys. B:, 1971, 4, 258. [all data]
Kuhn, 1932
Kuhn, H.,
Uber spektren von unecht gebundenen molekulen (polarisationsmolekulen) K2, Na2, Cs2 und verbreiterung von absorptionslinien,
Z. Phys., 1932, 76, 782. [all data]
Chakraborti, 1937
Chakraborti, B.K.,
On a new type of absorption bands of potassium vapour,
Indian J. Phys., 1937, 10, 155. [all data]
Okuda, 1936
Okuda, T.,
Narrow continuous band of potassium in the extreme red,
Nature (London), 1936, 138, 168. [all data]
Yoshinaga, 1937
Yoshinaga, H.,
New ultraviolet absorption bands of sodium and potassium molecules,
Proc. Phys. Math. Soc. Jpn., 1937, 19, 847. [all data]
Sinha, 1950
Sinha, S.P.,
Ultra-violet bands of K2,
Proc. Phys. Soc. London Sect. A, 1950, 63, 952. [all data]
Sinha, 1948
Sinha, S.P.,
Blue and ultra-violet bands of K2,
Proc. Phys. Soc. London, 1948, 60, 436. [all data]
Yamamoto, 1929
Yamamoto,
Revised by Crane and Christy, 1930, 1929, 355. [all data]
Loomis, 1931
Loomis, F.W.,
Rotational structure of the red bands of potassium,
Phys. Rev., 1931, 38, 2153. [all data]
Loomis and Nusbaum, 1932
Loomis, F.W.; Nusbaum, R.E.,
Magnetic rotation spectrum and heat of dissociation of the potassium molecule,
Phys. Rev., 1932, 39, 89. [all data]
Tango, Link, et al., 1968
Tango, W.J.; Link, J.K.; Zare, R.N.,
Spectroscopy of K2 using laser-induced fluorescence,
J. Chem. Phys., 1968, 49, 4264. [all data]
Crane and Christy, 1930
Crane, W.O.; Christy, A.,
Vibrational quantum analysis of the potassium infrared absorption bands,
Phys. Rev., 1930, 36, 421. [all data]
Sorokin and Lankard, 1971
Sorokin, P.P.; Lankard, J.R.,
Emission spectra of alkali-metal molecules observed with a heat-pipe discharge tube,
J. Chem. Phys., 1971, 55, 3810. [all data]
Geittner, 1975
Geittner, P.,
Bestimmung der Triplett-Potentialdaten fur das K2-Stossmolekul,
Z. Phys., 1975, 272, 359. [all data]
Kusch, Millman, et al., 1939
Kusch, P.; Millman, S.; Rabi, I.I.,
The nuclear magnetic moments of N14, Na23, K39 and Cs133,
Phys. Rev., 1939, 55, 1176. [all data]
Logan, Cote, et al., 1952
Logan, R.A.; Cote, R.E.; Kusch, P.,
The sign of the quadrupole interaction energy in diatomic molecules,
Phys. Rev., 1952, 86, 280. [all data]
Brooks, Anderson, et al., 1963
Brooks, R.A.; Anderson, C.H.; Ramsey, N.F.,
Rotational magnetic moments of diatomic alkalis,
Phys. Rev. Lett., 1963, 10, 441. [all data]
Tango and Zare, 1970
Tango, W.J.; Zare, R.N.,
Radiative lifetime of the B1Πu state of K2,
J. Chem. Phys., 1970, 53, 3094. [all data]
Baumgartner, Demtroder, et al., 1970
Baumgartner, G.; Demtroder, W.; Stock, M.,
Lifetime-measurements of alkali-molecules excited by different laserlines,
Z. Phys., 1970, 232, 462. [all data]
Lapp and Harris, 1966
Lapp, M.; Harris, L.P.,
Absorption cross sections of alkali-vapor molecules: I. Cs2 in the visible. II. K2 in the red,
J. Quant. Spectrosc. Radiat. Transfer, 1966, 6, 169. [all data]
Carroll, 1937
Carroll, T.,
Magnetic rotation spectra of diatomic molecules,
Phys. Rev., 1937, 52, 822. [all data]
Lewis, 1931
Lewis, L.C.,
Die bestimmung des gleichgewichts zwischen den atomen und den molekulen eines alkalidampfes mit einer molekularstrahlmethode,
Z. Phys., 1931, 69, 786. [all data]
Lee and Mahan, 1965
Lee, Y.-T.; Mahan, B.H.,
Photosensitized ionization of alkali-metal vapors,
J. Chem. Phys., 1965, 42, 2893. [all data]
Williams, 1967
Williams, R.A.,
Photoionization of potassium vapor,
J. Chem. Phys., 1967, 47, 4281. [all data]
Bellomonte, Cavaliere, et al., 1974
Bellomonte, L.; Cavaliere, P.; Ferrante, G.,
Alkali molecular ion energies and expectation values in a model-potential treatment,
J. Chem. Phys., 1974, 61, 3225. [all data]
Notes
Go To: Top, Gas phase ion energetics data, Constants of diatomic molecules, References
- Symbols used in this document:
AE Appearance energy EA Electron affinity IE (evaluated) Recommended ionization energy - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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