1
|
Stocka J, Platakyte R, McFadden T, Ceponkus J, Aleksa V, Hanna A, Sablinskas V, Rodziewicz P, Guirgis G. Conformational diversity of 1‑chloro-1-chloromethylsilacyclohexane with experimental (Raman and IR) and computational (DFT, MP2) methods. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2021.131644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
2
|
Bernath PF, Sibert Iii EL. Cyclohexane Vibrations: High-Resolution Spectra and Anharmonic Local Mode Calculations. J Phys Chem A 2020; 124:9991-10000. [PMID: 33210908 DOI: 10.1021/acs.jpca.0c09185] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
High-resolution infrared absorption spectra of cyclohexane have been recorded from 1100 to 4000 cm-1 at room temperature and 241 K. Cyclohexane is an oblate symmetric top with D3d symmetry. A rotational analysis was obtained for the ν27 (eu) and ν14 (a2u) CH2 scissor modes at 1452.9 and 1456.4 cm-1, respectively. Several combination modes were also assigned and rotationally analyzed. The C-H stretching modes are perturbed by overtone and combination modes of the CH2 scissor vibrations, and an anharmonic local mode calculation was needed to interpret the spectra. The four main strong allowed C-H stretching modes appear as two a2u eu pairs near at 2862 and 2933 cm-1. The Fermi-resonance local mode model coupling terms give physical insight into the effects that organize the cyclohexane vibrational energy levels. The unstrained cyclohexane molecule is a useful paradigm for six-membered rings in larger chemical and biological systems.
Collapse
Affiliation(s)
- Peter F Bernath
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, Virginia 23529, United States
| | - Edwin L Sibert Iii
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| |
Collapse
|
3
|
Chatterley AS, Baatrup MO, Schouder CA, Stapelfeldt H. Laser-induced alignment dynamics of gas phase CS 2 dimers. Phys Chem Chem Phys 2020; 22:3245-3253. [PMID: 31995073 DOI: 10.1039/c9cp06260b] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Rotational dynamics of gas phase carbon disulfide (CS2) dimers were induced by a moderately intense, circularly polarized alignment laser pulse and measured as a function of time by Coulomb explosion imaging with an intense fs probe pulse. For the alignment pulse, two different temporal intensity profiles were used: a truncated pulse with a 150 ps turn-on and a 8 ps turn-off, or a 'kick' pulse with a duration of 1.3 ps. For both types of pulse, rich rotational dynamics with characteristic full and fractional revivals were recorded, showing that the intermolecular carbon-carbon axis periodically aligns along the propagation direction of the laser pulses. The truncated pulse gave the strongest alignment, which we rationalize as being due to a flat relative phase between the components in the rotational wave packet generated. Fourier analysis of the alignment dynamics gave well-spaced peaks which were fit to determine the rotational constant, B, and the centrifugal constant, DJ, for the ground state of the dimer. Our results agree with values from high-resolution IR spectroscopy. Numerical simulations of the alignment accurately reproduced the experimental dynamics when the truncated pulse or a low intensity kick pulse was used, but failed to reproduce the dynamics induced by a high intensity kick pulse. We posit that the discrepancy is due to excitation of the intermolecular torsional motion by the kick pulse.
Collapse
Affiliation(s)
| | - Mia O Baatrup
- Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark
| | - Constant A Schouder
- Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark
| | | |
Collapse
|
4
|
|
5
|
Rosenberg D, Damari R, Kallush S, Fleischer S. Rotational Echoes: Rephasing of Centrifugal Distortion in Laser-Induced Molecular Alignment. J Phys Chem Lett 2017; 8:5128-5135. [PMID: 28950060 DOI: 10.1021/acs.jpclett.7b02215] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We study and demonstrate the rephasing property of the echo response in a multilevel rotational system of iodomethane via long time-resolved optical birefringence measurements. The strong centrifugal distortion of iodomethane is utilized as a dephasing mechanism imprinted on the echo signal and is shown to rephase throughout its evolution. The dependence of the echo signal amplitude on the driving pulses' intensities is theoretically and experimentally explored. The analogy to Hahn's spin echoes is discussed, and a quantum-mechanical version of Hahn's track runners is provided for the case of multilevel rotational system.
Collapse
Affiliation(s)
- Dina Rosenberg
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University , Tel Aviv 6997801, Israel
- Tel-Aviv University Center for Light-Matter Interaction , Tel Aviv 6997801, Israel
| | - Ran Damari
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University , Tel Aviv 6997801, Israel
- Tel-Aviv University Center for Light-Matter Interaction , Tel Aviv 6997801, Israel
| | - Shimshon Kallush
- Department of Physics and Optical Engineering, ORT Braude College , P.O. Box 78, Karmiel 21982, Israel
- The Fritz Haber Research Center and The Institute of Chemistry, The Hebrew University , Jerusalem 91904, Israel
| | - Sharly Fleischer
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University , Tel Aviv 6997801, Israel
- Tel-Aviv University Center for Light-Matter Interaction , Tel Aviv 6997801, Israel
| |
Collapse
|
6
|
Den T, Menzi S, Frey HM, Leutwyler S. Accurate gas-phase structure of para-dioxane by fs Raman rotational coherence spectroscopy and ab initio calculations. J Chem Phys 2017; 147:074306. [PMID: 28830173 DOI: 10.1063/1.4997633] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
p-Dioxane is non-polar, hence its rotational constants cannot be determined by microwave rotational coherence spectroscopy (RCS). We perform high-resolution gas-phase rotational spectroscopy of para-dioxane-h8 and -d8 using femtosecond time-resolved Raman RCS in a gas cell at T = 293 K and in a pulsed supersonic jet at T∼130 K. The inertial tensor of p-dioxane-h8 is strongly asymmetric, leading to a large number of asymmetry transients in its RCS spectrum. In contrast, the d8-isotopomer is a near-oblate symmetric top that exhibits a much more regular RCS spectrum with few asymmetry transients. Fitting the fs Raman RCS transients of p-dioxane-h8 to an asymmetric-top model yields the ground-state rotational constants A0 = 5084.4(5) MHz, B0 = 4684(1) MHz, C0 = 2744.7(8) MHz, and (A0 + B0)/2 = 4884.5(7) MHz (±1σ). The analogous values for p-dioxane-d8 are A0 = 4083(2) MHz, B0 = 3925(4) MHz, C0 = 2347.1(6) MHz, and (A0 + B0)/2 = 4002.4(6) MHz. We determine the molecular structure with a semi-experimental approach involving the highly correlated coupled-cluster singles, doubles and iterated triples method and the cc-pCVXZ basis set series from double- to quadruple-zeta (X = D, T, Q). Combining the calculated vibrationally averaged rotational constants A0calc(X),B0calc(X),C0calc(X) for increasing basis-set size X with non-linear extrapolation to the experimental constants A0exp,B0exp,C0exp allows to determine the equilibrium ground state structure of p-dioxane. For instance, the equilibrium C-C and C-O bond lengths are re(CC) = 1.5135(3) Å and re(CO) = 1.4168(4) Å, and the four axial C-H bond lengths are 0.008 Å longer than the four equatorial ones. The latter is ascribed to the trans-effect (anomeric effect), i.e., the partial delocalization of the electron lone-pairs on the O atoms that are oriented trans, relative to the axial CH bonds.
Collapse
Affiliation(s)
- Takuya Den
- Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, CH-3000 Bern 9, Switzerland
| | - Samuel Menzi
- Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, CH-3000 Bern 9, Switzerland
| | - Hans-Martin Frey
- Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, CH-3000 Bern 9, Switzerland
| | - Samuel Leutwyler
- Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, CH-3000 Bern 9, Switzerland
| |
Collapse
|
7
|
Den T, Frey HM, Felker PM, Leutwyler S. Rotational constants and structure of para-difluorobenzene determined by femtosecond Raman coherence spectroscopy: A new transient type. J Chem Phys 2016; 143:144306. [PMID: 26472378 DOI: 10.1063/1.4932602] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Femtosecond Raman rotational coherence spectroscopy (RCS) detected by degenerate four-wave mixing is a background-free method that allows to determine accurate gas-phase rotational constants of non-polar molecules. Raman RCS has so far mostly been applied to the regular coherence patterns of symmetric-top molecules, while its application to nonpolar asymmetric tops has been hampered by the large number of RCS transient types, the resulting variability of the RCS patterns, and the 10(3)-10(4) times larger computational effort to simulate and fit rotational Raman RCS transients. We present the rotational Raman RCS spectra of the nonpolar asymmetric top 1,4-difluorobenzene (para-difluorobenzene, p-DFB) measured in a pulsed Ar supersonic jet and in a gas cell over delay times up to ∼2.5 ns. p-DFB exhibits rotational Raman transitions with ΔJ = 0, 1, 2 and ΔK = 0, 2, leading to the observation of J -, K -, A -, and C-type transients, as well as a novel transient (S-type) that has not been characterized so far. The jet and gas cell RCS measurements were fully analyzed and yield the ground-state (v = 0) rotational constants A0 = 5637.68(20) MHz, B0 = 1428.23(37) MHz, and C0 = 1138.90(48) MHz (1σ uncertainties). Combining the A0, B0, and C0 constants with coupled-cluster with single-, double- and perturbatively corrected triple-excitation calculations using large basis sets allows to determine the semi-experimental equilibrium bond lengths re(C1-C2) = 1.3849(4) Å, re(C2-C3) = 1.3917(4) Å, re(C-F) = 1.3422(3) Å, and re(C2-H2) = 1.0791(5) Å.
Collapse
Affiliation(s)
- Takuya Den
- Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, CH-3000 Bern 9, Switzerland
| | - Hans-Martin Frey
- Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, CH-3000 Bern 9, Switzerland
| | - Peter M Felker
- Department of Chemistry and Biochemistry, University of California at Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90095-1569, USA
| | - Samuel Leutwyler
- Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, CH-3000 Bern 9, Switzerland
| |
Collapse
|
8
|
Sakhaee N, Jalili S, Darvish F. Spherical conformational landscape shed new lights on fluxional nature of cyclopentane and its derivatives, confirmed by their Raman spectra. COMPUT THEOR CHEM 2016. [DOI: 10.1016/j.comptc.2016.06.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
9
|
Kowalewski P, Frey HM, Infanger D, Leutwyler S. Probing the Structure, Pseudorotation, and Radial Vibrations of Cyclopentane by Femtosecond Rotational Raman Coherence Spectroscopy. J Phys Chem A 2015; 119:11215-25. [DOI: 10.1021/acs.jpca.5b07930] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Philipp Kowalewski
- Department
of Chemistry and Biochemistry, University of Bern, Freiestrasse
3, CH-3012 Bern, Switzerland
| | - Hans-Martin Frey
- Department
of Chemistry and Biochemistry, University of Bern, Freiestrasse
3, CH-3012 Bern, Switzerland
| | - Daniel Infanger
- Department
of Chemistry and Biochemistry, University of Bern, Freiestrasse
3, CH-3012 Bern, Switzerland
| | - Samuel Leutwyler
- Department
of Chemistry and Biochemistry, University of Bern, Freiestrasse
3, CH-3012 Bern, Switzerland
| |
Collapse
|
10
|
Den TS, Frey HM, Leutwyler S. Accurate rotational constant and bond lengths of hexafluorobenzene by femtosecond rotational Raman coherence spectroscopy and ab initio calculations. J Chem Phys 2014; 141:194303. [DOI: 10.1063/1.4901284] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
- Takuya S. Den
- Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, CH-3000 Bern 9, Switzerland
| | - Hans-Martin Frey
- Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, CH-3000 Bern 9, Switzerland
| | - Samuel Leutwyler
- Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, CH-3000 Bern 9, Switzerland
| |
Collapse
|
11
|
Demaison J, Craig NC, Groner P, Écija P, Cocinero EJ, Lesarri A, Rudolph HD. Accurate Equilibrium Structures for Piperidine and Cyclohexane. J Phys Chem A 2014; 119:1486-93. [DOI: 10.1021/jp505765t] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jean Demaison
- Laboratoire
de Physique des Lasers, Atomes et Molécules, Université de Lille 1, 59655 Villeneuve d’Ascq Cedex, France
| | - Norman C. Craig
- Department
of Chemistry and Biochemistry, Oberlin College, Oberlin, Ohio 44074, United States
| | - Peter Groner
- Department
of Chemistry, University of Missouri—Kansas City, Kansas City, Missouri 64110-2499, United States
| | - Patricia Écija
- Departamento
de Química Física, Facultad de Ciencia y Tecnología, Universidad del País Vasco (UPV-EHU), Ap. 644, E-48080 Bilbao, Spain
| | - Emilio J. Cocinero
- Departamento
de Química Física, Facultad de Ciencia y Tecnología, Universidad del País Vasco (UPV-EHU), Ap. 644, E-48080 Bilbao, Spain
| | - Alberto Lesarri
- Departamento
de Química Física y Química Inorgánica,
Facultad de Ciencias, Universidad de Valladolid, E-47011 Valladolid, Spain
| | | |
Collapse
|