1
|
|
2
|
Burton MA, Russ BT, Bucchino MP, Sheridan PM, Ziurys LM. The ground state of KO revisited: the millimeter and submillimeter spectrum of potassium oxide. Phys Chem Chem Phys 2019; 21:21960-21965. [PMID: 31552946 DOI: 10.1039/c9cp03465j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The millimeter/sub-millimeter spectrum of the KO radical has been recorded in the frequency range 90-534 GHz using direct absorption methods. The radical was synthesized by reacting potassium vapor, produced with a Broida-type oven, with either N2O or O2 mixed in argon carrier gas. Twenty-seven rotational transitions of KO were measured, each exhibiting a doublet structure with a relatively small splitting (∼100-200 MHz) that increased noticeably with frequency. A perturbation was apparent in the rotational lines at energies above ∼120 cm-1, which was more prominent in one doublet component. The data were successfully fit with a Hund's case (c) Hamiltonian, assuming that spectra arise from a 2Πi state, and rotational and effective lambda-doubling constants were determined. Higher order centrifugal distortion terms were needed to account for the perturbation. The spectra could also be fit as a 2Σ+ ground state, but less successfully, and the resulting rotational constant of B = 8235.4 MHz disagreed significantly with that predicted by theory. On the basis of the experimental data, the ground electronic state of KO has been assigned as 2Πi, although the 2Σ+ assignment cannot be entirely ruled out.
Collapse
Affiliation(s)
- Mark A Burton
- Department of Chemistry and Biochemistry, Department of Astronomy, and Steward Observatory, University of Arizona, 1305 E. 4th Street, Tucson, AZ 85719, USA.
| | | | | | | | | |
Collapse
|
3
|
Sharma K, Friedrich B. Pair-eigenstates and mutual alignment of coupled molecular rotors in a magnetic field. Phys Chem Chem Phys 2016; 18:13467-77. [PMID: 27126576 DOI: 10.1039/c6cp00390g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We examine the rotational states of a pair of polar (2)Σ molecules subject to a uniform magnetic field. The electric dipole-dipole interaction between the molecules creates entangled pair-eigenstates of two types. In one type, the Zeeman interaction between the inherently paramagnetic molecules and the magnetic field destroys the entanglement of the pair-eigenstates, whereas in the other type it does not. The pair-eigenstates exhibit numerous intersections, which become avoided for pair-eigenstates comprised of individual states that meet the selection rules ΔJi = 0, ± 1, ΔNi = 2n (n = 0, ±1, ±2,…), and ΔMi = 0, ± 1 imposed by the electric dipole-dipole operator. Here Ji, Ni and Mi are the total, rotational and projection angular momentum quantum numbers of molecules i = 1, 2 in the absence of the electric dipole-dipole interaction. We evaluate the mutual alignment of the pair-eigenstates and find it to be independent of the magnetic field, except for states that undergo avoided crossings, in which case the alignment of the interacting states is interchanged at the magnetic field corresponding to the crossing point. We present an analytic model which provides ready estimates of the pairwise alignment cosine that characterises the mutual alignment of the pair of coupled rotors.
Collapse
Affiliation(s)
- Ketan Sharma
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany.
| | - Bretislav Friedrich
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany.
| |
Collapse
|
4
|
Gómez Martín JC, Garraway SA, Plane JMC. Reaction Kinetics of Meteoric Sodium Reservoirs in the Upper Atmosphere. J Phys Chem A 2016; 120:1330-46. [PMID: 25723735 DOI: 10.1021/acs.jpca.5b00622] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The gas-phase reactions of a selection of sodium-containing species with atmospheric constituents, relevant to the chemistry of meteor-ablated Na in the upper atmosphere, were studied in a fast flow tube using multiphoton ionization time-of-flight mass spectrometry. For the first time, unambiguous observations of NaO and NaOH in the gas phase under atmospheric conditions have been achieved. This enabled the direct measurement of the rate constants for the reactions of NaO with H2, H2O, and CO, and of NaOH with CO2, which at 300-310 K were found to be (at 2σ confidence level): k(NaO + H2O) = (2.4 ± 0.6) × 10(-10) cm(3) molecule (-1) s(-1), k(NaO + H2) = (4.9 ± 1.2) × 10(-12) cm(3) molecule (-1) s(-1), k(NaO + CO) = (9 ± 4) × 10(-11) cm(3) molecule (-1) s(-1), and k(NaOH + CO2 + M) = (7.6 ± 1.6) × 10(-29) cm(6) molecule (-2) s(-1) (P = 1-4 Torr). The NaO + H2 reaction was found to make NaOH with a branching ratio ≥ 99%. A combination of quantum chemistry and statistical rate theory calculations are used to interpret the reaction kinetics and extrapolate the atmospherically relevant experimental results to mesospheric temperatures and pressures. The NaO + H2O and NaOH + CO2 reactions act sequentially to provide the major atmospheric sink of meteoric Na and therefore have a significant impact on the underside of the Na layer in the terrestrial mesosphere: the newly determined rate constants shift the modeled peak to about 93 km, i.e., 2 km higher than observed by ground-based lidars. This highlights further uncertainties in the Na chemistry cycle such as the unknown rate constant of the NaOH + H reaction. The fast Na-recycling reaction between NaO and CO and a re-evaluated rate constant of the NaO + CO2 sink should be now considered in chemical models of the Martian Na layer.
Collapse
Affiliation(s)
- J C Gómez Martín
- School of Chemistry, University of Leeds , Woodhouse Lane, LS2 9JT, Leeds, U.K
| | - S A Garraway
- School of Chemistry, University of Leeds , Woodhouse Lane, LS2 9JT, Leeds, U.K
| | - J M C Plane
- School of Chemistry, University of Leeds , Woodhouse Lane, LS2 9JT, Leeds, U.K
| |
Collapse
|
5
|
Karra M, Sharma K, Friedrich B, Kais S, Herschbach D. Prospects for quantum computing with an array of ultracold polar paramagnetic molecules. J Chem Phys 2016; 144:094301. [DOI: 10.1063/1.4942928] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Mallikarjun Karra
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany
| | - Ketan Sharma
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany
| | - Bretislav Friedrich
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany
| | - Sabre Kais
- Departments of Chemistry, Physics and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, USA
| | - Dudley Herschbach
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, USA
| |
Collapse
|
6
|
Buenker RJ, Liebermann HP. Configuration interaction calculations of potential curves and annihilation rates for positronic complexes of alkali monoxides. J Chem Phys 2009; 131:114107. [DOI: 10.1063/1.3231685] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
7
|
Mintz B, Chan B, Sullivan MB, Buesgen T, Scott AP, Kass SR, Radom L, Wilson AK. Structures and Thermochemistry of the Alkali Metal Monoxide Anions, Monoxide Radicals, and Hydroxides. J Phys Chem A 2009; 113:9501-10. [DOI: 10.1021/jp9034826] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Benjamin Mintz
- Center for Advanced Scientific Computing and Modeling (CASCaM), Department of Chemistry, University of North Texas, Denton, Texas 76203-5070, School of Chemistry and Centre of Excellence for Free Radical Chemistry and Biotechnology, University of Sydney, Sydney, NSW 2006, Australia, Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia, and Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455-0431
| | - Bun Chan
- Center for Advanced Scientific Computing and Modeling (CASCaM), Department of Chemistry, University of North Texas, Denton, Texas 76203-5070, School of Chemistry and Centre of Excellence for Free Radical Chemistry and Biotechnology, University of Sydney, Sydney, NSW 2006, Australia, Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia, and Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455-0431
| | - Michael B. Sullivan
- Center for Advanced Scientific Computing and Modeling (CASCaM), Department of Chemistry, University of North Texas, Denton, Texas 76203-5070, School of Chemistry and Centre of Excellence for Free Radical Chemistry and Biotechnology, University of Sydney, Sydney, NSW 2006, Australia, Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia, and Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455-0431
| | - Thomas Buesgen
- Center for Advanced Scientific Computing and Modeling (CASCaM), Department of Chemistry, University of North Texas, Denton, Texas 76203-5070, School of Chemistry and Centre of Excellence for Free Radical Chemistry and Biotechnology, University of Sydney, Sydney, NSW 2006, Australia, Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia, and Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455-0431
| | - Anthony P. Scott
- Center for Advanced Scientific Computing and Modeling (CASCaM), Department of Chemistry, University of North Texas, Denton, Texas 76203-5070, School of Chemistry and Centre of Excellence for Free Radical Chemistry and Biotechnology, University of Sydney, Sydney, NSW 2006, Australia, Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia, and Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455-0431
| | - Steven R. Kass
- Center for Advanced Scientific Computing and Modeling (CASCaM), Department of Chemistry, University of North Texas, Denton, Texas 76203-5070, School of Chemistry and Centre of Excellence for Free Radical Chemistry and Biotechnology, University of Sydney, Sydney, NSW 2006, Australia, Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia, and Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455-0431
| | - Leo Radom
- Center for Advanced Scientific Computing and Modeling (CASCaM), Department of Chemistry, University of North Texas, Denton, Texas 76203-5070, School of Chemistry and Centre of Excellence for Free Radical Chemistry and Biotechnology, University of Sydney, Sydney, NSW 2006, Australia, Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia, and Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455-0431
| | - Angela K. Wilson
- Center for Advanced Scientific Computing and Modeling (CASCaM), Department of Chemistry, University of North Texas, Denton, Texas 76203-5070, School of Chemistry and Centre of Excellence for Free Radical Chemistry and Biotechnology, University of Sydney, Sydney, NSW 2006, Australia, Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia, and Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455-0431
| |
Collapse
|
8
|
Slanger TG, Cosby PC, Huestis DL, Saiz-Lopez A, Murray BJ, O'Sullivan DA, Plane JMC, Allende Prieto C, Martin-Torres FJ, Jenniskens P. Variability of the mesospheric nightglow sodium D2/D1ratio. ACTA ACUST UNITED AC 2005. [DOI: 10.1029/2005jd006078] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
9
|
|
10
|
Self DE, M. C. Plane J. Absolute photolysis cross-sections for NaHCO3 , NaOH, NaO, NaO2and NaO3 : implications for sodium chemistry in the upper mesosphere. Phys Chem Chem Phys 2002. [DOI: 10.1039/b107078a] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
11
|
Setzer KD, Fink EH, Alekseyev AB, Liebermann HP, Buenker RJ. Experimental and Theoretical Study of the Electronic States and Spectra of TeH and TeLi. JOURNAL OF MOLECULAR SPECTROSCOPY 2001; 206:181-197. [PMID: 11281700 DOI: 10.1006/jmsp.2001.8301] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Gas-phase emission spectra of the hitherto unknown free radical TeLi have been measured in the NIR range with a Fourier-transform spectrometer. The emissions were observed from a fast flow system in which tellurium vapor in argon carrier gas was passed through a microwave discharge and mixed with lithium vapor in an observation tube. Two systems of blue-degraded bands were measured at high spectral resolution in the ranges 8000-9000 and 5700-6700 cm(-1) and vibrational and rotational analyses were performed. In order to aid in the analysis of the experimental data, a series of relativistic configuration interaction calculations has been carried out to obtain potential curves for the low-lying states of TeLi and the isovalent TeH and also electric dipole transition moments connecting them. As in the TeH system, the ground state of TeLi is found to be X(2)Pi(i), but with a remarkably smaller spin-orbit splitting. The TeLi calculations indicate a strongly bound A(2)Sigma(+) state, while in TeH the analogous state is computed to lie significantly higher at approximately 32 000 cm(-1), and it is strongly predissociated. Based on the theoretical analysis, the observed TeLi band systems are assigned to the transitions A(2)Sigma(+)(A1/2)-->X(1)(2)Pi(3/2)(X(1)3/2) and A(2)Sigma(+)(A1/2)-->X(2)(2)Pi(1/2)(X(2)1/2). Analysis of the spectra has yielded the molecular constants (in cm(-1)) X(1)(2)Pi(3/2):omega(e)=457.49(3), omega(e)x(e)=2.482(9), B(0)=0.408908(8); X(2)(2)Pi(1/2): T(e)=2353.44(3), omega(e)=456.28(4), omega(e)x(e)=2.635(8), B(0)=0.414954(8), p(0)=1.00637(4); A(2)Sigma(+): T(e)=8574.64(2), omega(e)=437.81(3), omega(e)x(e)=2.581(8), B(0)=0.423903(8), p(0)=-0.19915(2), where the numbers in parentheses are the standard deviations of the parameters. Comparison of the isovalent TeLi and TeH systems emphasizes that the difference in bonding character (ionic in TeLi vs covalent in TeH) is responsible for qualitative differences in the electronic spectra of these two molecules. Copyright 2001 Academic Press.
Collapse
Affiliation(s)
- K. D. Setzer
- Fachbereich 9-Physikalische Chemie, Bergische Universität-Gesamthochschule Wuppertal, Wuppertal, 42097, Federal Republic of Germany
| | | | | | | | | |
Collapse
|
12
|
Griffin J, Worsnop DR, Brown RC, Kolb CE, Herschbach DR. Chemical Kinetics of the NaO (A 2Σ+) + O(3P) Reaction. J Phys Chem A 2000. [DOI: 10.1021/jp002641m] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- J. Griffin
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, and Center for Cloud and Aerosol Chemistry, Aerodyne Research, Inc., Billerica, Massachusetts 01821-3976
| | - D. R. Worsnop
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, and Center for Cloud and Aerosol Chemistry, Aerodyne Research, Inc., Billerica, Massachusetts 01821-3976
| | - R. C. Brown
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, and Center for Cloud and Aerosol Chemistry, Aerodyne Research, Inc., Billerica, Massachusetts 01821-3976
| | - C. E. Kolb
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, and Center for Cloud and Aerosol Chemistry, Aerodyne Research, Inc., Billerica, Massachusetts 01821-3976
| | - D. R. Herschbach
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, and Center for Cloud and Aerosol Chemistry, Aerodyne Research, Inc., Billerica, Massachusetts 01821-3976
| |
Collapse
|
13
|
Herschbach D. Fifty years in physical chemistry: homage to mentors, methods, and molecules. Annu Rev Phys Chem 2000; 51:1-39. [PMID: 11031274 DOI: 10.1146/annurev.physchem.51.1.1] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A nostalgic account is given of my scientific odyssey, recalling early encounters, some fateful, some just fun, with mentors, methods, and molecules. These include stories of my student years at Stanford, pursuing chemical kinetics with Harold Johnston; graduate study at Harvard, doing molecular spectroscopy with Bright Wilson; and fledgling faculty years at Berkeley, launching molecular beam studies of reaction dynamics. A few vignettes from my "ever after " era on the Harvard faculty emphasize thematic motivations or methods inviting further exploration. An Appendix provides a concise listing of colleagues in research and the topics we have pursued.
Collapse
Affiliation(s)
- D Herschbach
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
| |
Collapse
|
14
|
Slanger TG, Cosby PC, Huestis DL, Osterbrock DE. Vibrational level distribution of O2(b1∑+g, v = 0-15) in the mesosphere and lower thermosphere region. ACTA ACUST UNITED AC 2000. [DOI: 10.1029/2000jd900256] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
15
|
Slanger TG, Osterbrock DE. Investigations of potassium, lithium, and sodium emission in the nightglow and OH cross calibration. ACTA ACUST UNITED AC 2000. [DOI: 10.1029/1999jd901027] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|