1
|
Terry LM, Foreman MM, Weber JM. Effects of Anion Size, Shape, and Solvation in Binding of Nitrate to Octamethyl Calix[4]pyrrole. J Phys Chem Lett 2024; 15:9481-9486. [PMID: 39254991 DOI: 10.1021/acs.jpclett.4c02347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/11/2024]
Abstract
We present cryogenic ion vibrational spectroscopy of complexes of the anion receptor octamethyl calix[4]pyrrole (omC4P) with nitrate in vacuo. We compare the resulting vibrational spectrum with that in deuterated acetonitrile solution, and we interpret the results using density functional theory. Nitrate binds to omC4P through hydrogen bonds between the four NH groups of the receptor and a single NO group of the nitrate ion. The shape of the ion breaks the C4v symmetry of the receptor, and this symmetry lowering is encoded in the pattern of the NH stretching modes of omC4P. We compare the spectrum of nitrate-omC4P with that of chloride-omC4P to discuss effects of ion size, shape, and solvent interaction on the ion binding behavior.
Collapse
Affiliation(s)
- Lane M Terry
- JILA and Department of Chemistry, University of Colorado, 440 UCB, Boulder, Colorado 80309-0440, United States
| | - Madison M Foreman
- JILA and Department of Chemistry, University of Colorado, 440 UCB, Boulder, Colorado 80309-0440, United States
| | - J Mathias Weber
- JILA and Department of Chemistry, University of Colorado, 440 UCB, Boulder, Colorado 80309-0440, United States
| |
Collapse
|
2
|
Terry LM, Foreman MM, Rasmussen AP, McCoy AB, Weber JM. Probing Ion-Receptor Interactions in Halide Complexes of Octamethyl Calix[4]Pyrrole. J Am Chem Soc 2024; 146:12401-12409. [PMID: 38652043 DOI: 10.1021/jacs.3c13445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
Ion receptors are molecular hosts that bind ionic guests, often with great selectivity. The interplay of solvation and ion binding in anion host-guest complexes in solution governs the binding efficiency and selectivity of such ion receptors. To gain molecular-level insight into the intrinsic binding properties of octamethyl calix[4]pyrrole (omC4P) host molecules with halide guest ions, we performed cryogenic ion vibrational spectroscopy (CIVS) of omC4P in complexes with fluoride, chloride, and bromide ions. We interpret the spectra using density functional theory, describing the infrared spectra of these complexes with both harmonic and anharmonic second-order vibrational perturbation theory (VPT2) calculations. The NH stretching modes of the pyrrole moieties serve as sensitive probes of the ion binding properties, as their frequencies encode the ion-receptor interactions. While scaled harmonic spectra reproduce the experimental NH stretching modes of the chloride and bromide complexes in broad strokes, the high proton affinity of fluoride introduces strong anharmonic effects. As a result, the spectrum of F-·omC4P is not even qualitatively captured by harmonic calculations, but it is recovered very well by VPT2 calculations. In addition, the VPT2 calculations recover the intricate coupling of the NH stretching modes with overtones and combination bands of CH stretching and NH bending modes and with low-frequency vibrations of the omC4P macrocycle, which are apparent for all of the halide ion complexes investigated here. A comparison of the CIVS spectra with infrared spectra of solutions of the same ion-receptor complexes in d3-acetonitrile and d6-acetone shows how ion solvation changes the ion-receptor interactions for the different halide ions.
Collapse
Affiliation(s)
- Lane M Terry
- JILA and Department of Chemistry, University of Colorado, 440 UCB, Boulder, Colorado 80309-0440, United States
| | - Madison M Foreman
- JILA and Department of Chemistry, University of Colorado, 440 UCB, Boulder, Colorado 80309-0440, United States
| | - Anne P Rasmussen
- JILA and Department of Chemistry, University of Colorado, 440 UCB, Boulder, Colorado 80309-0440, United States
- Department of Physics and Astronomy, Aarhus University, 8000 Aarhus, Denmark
| | - Anne B McCoy
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - J Mathias Weber
- JILA and Department of Chemistry, University of Colorado, 440 UCB, Boulder, Colorado 80309-0440, United States
| |
Collapse
|
3
|
Ilbeigi V, Valadbeigi Y, Moravsky L, Matejčík Š. Formic Acid as a Dopant for Atmospheric Pressure Chemical Ionization for Negative Polarity of Ion Mobility Spectrometry and Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:2051-2060. [PMID: 37498108 DOI: 10.1021/jasms.3c00225] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/28/2023]
Abstract
Formic acid (FA) is introduced as a potent dopant for atmospheric pressure chemical ionization (APCI) for ion mobility spectrometry (IMS) and mass spectrometry (MS). The mechanism of chemical ionization with the FA dopant was studied in the negative polarity using a corona discharge (CD)-IMS-MS technique in air. Standard reactant ions of the negative polarity present in air are O2-·(CO2)n·(H2O)m (m = 0, 1 and n = 1, 2) clusters. Introduction of the FA dopant resulted in the production of HCOO-·FA reactant ions. The effect of the FA dopant on the APCI of different classes of compounds was investigated, including plant hormones, pesticides, acidic drugs, and explosives. FA dopant APCI resulted in deprotonation and/or adduct ion formation, [M - H]- and [M + HCOO]-, respectively. Supporting density functional theory (DFT) calculations showed that the ionization mechanism depended on the gas-phase acidity of the compounds. FA dopant APCI led to the improvement of detection sensitivity, suppression of fragmentation, and changes in the ion mobilities of the analyte ions for analytes with suitable molecular structures and gas acidity.
Collapse
Affiliation(s)
- Vahideh Ilbeigi
- Department of Experimental Physics, Faculty of Mathematics, Physics and Informatics, Comenius University in Bratislava, Mlynská dolina F2, 84248 Bratislava, Slovakia
| | - Younes Valadbeigi
- Department of Chemistry, Faculty of Science, Imam Khomeini International University, 34148-96818 Qazvin, Iran
| | - Ladislav Moravsky
- Department of Experimental Physics, Faculty of Mathematics, Physics and Informatics, Comenius University in Bratislava, Mlynská dolina F2, 84248 Bratislava, Slovakia
| | - Štefan Matejčík
- Department of Experimental Physics, Faculty of Mathematics, Physics and Informatics, Comenius University in Bratislava, Mlynská dolina F2, 84248 Bratislava, Slovakia
| |
Collapse
|
4
|
Dramatic effect of the nature of R on the intrinsic acidity and basicity of potential astrochemical R–C≡COH and R–C≡CSH compounds. Theor Chem Acc 2023. [DOI: 10.1007/s00214-023-02967-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
Abstract
AbstractThe effect of changing the nature of the R substituent from the first row (H, Li, BeH, BH2, CH3, NH2, OH and F) to second row (Na, MgH, AlH2, SiH3, PH2, SH and Cl) on the intrinsic acidity and basicity of R–C≡COH and R–C≡CSH compounds was investigated through the use of G4 high-level ab initio calculation. The variation of the acidity and basicity of the R–C≡CSH derivatives as a function of R is practically parallel to that found for the corresponding R–C≡COH analogs; though the basicities of the former are 9–14% higher than those of the latter, the acidity gap being very small (~ 2%). When this analysis is extended to the derivatives in which the triple CC bond is replaced by a double or single bond, it is found that the acidity gap increases systematically as the CC bond goes from triple to single; whereas, as expected for the basicity, the trend is the opposite. Quite surprisingly, however, the variation of the basicity of R–C≡CX (X = OH, SH) compounds with the nature of the first-row substituents, R, is remarkably different from that produced by the second-row analogs. The same is observed as far as intrinsic acidities are concerned. These dissimilarities reflect the rather different changes in the strength of the CC and the CX (X = OH, SH) bonds when a first-row substituent is replaced by the second-row analog, as reflected in the atoms in molecules (AIM), natural bond orbital (NBO) and the electron localization function (ELF) analyses of the corresponding species.
Collapse
|
5
|
Glasovac Z, Barešić L, Margetić D. A DFT Investigation of the Reactivity of Guanidinium Salts in Tandem aza-Michael Addition/Intramolecular Cyclization. Molecules 2023; 28:molecules28052218. [PMID: 36903463 PMCID: PMC10005421 DOI: 10.3390/molecules28052218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/22/2023] [Accepted: 02/24/2023] [Indexed: 03/06/2023] Open
Abstract
A proposed mechanism of the reaction of guanidinium chlorides with dimethyl acetylenedicarboxylate in a tandem aza-Michael addition reaction/intramolecular cyclization was investigated by DFT M06-2X and B3LYP computational approaches. The energies of the products were compared against the G3, M08-HX, M11, and wB97xD data or experimentally obtained product ratios. The structural diversity of the products was interpreted by the concurrent formation of different tautomers formed in situ upon deprotonation with a 2-chlorofumarate anion. A comparison of relative energies of the characteristic stationary points along the examined reaction paths indicated that the initial nucleophilic addition is energetically the most demanding process. The overall reaction is strongly exergonic, as predicted by both methods, which is primarily due to methanol elimination during the intramolecular cyclization step producing cyclic amide structures. Formation of a five-membered ring upon intramolecular cyclization is highly favored for the acyclic guanidine, while optimal product structure for the cyclic guanidines is based on a 1,5,7-triaza [4.3.0]-bicyclononane skeleton. Relative stabilities of the possible products calculated by the employed DFT methods were compared against the experimental product ratio. The best agreement was obtained for the M08-HX approach while the B3LYP approach provided somewhat better results than the M06-2X and M11 methods.
Collapse
|
6
|
Kao MH, Orr-Ewing AJ. Charge-Separated Reactive Intermediates from the UV Photodissociation of Chlorobenzene in Solution. J Phys Chem A 2022; 126:6934-6943. [PMID: 36148486 PMCID: PMC9549464 DOI: 10.1021/acs.jpca.2c05327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Although ultraviolet
(UV)-induced photochemical cleavage of carbon–halogen
bonds in gaseous halocarbons is mostly homolytic, the photolysis of
chlorobenzene in solution has been proposed to produce a phenyl cation,
c-C6H5+, which is a highly reactive
intermediate of potential use in chemical synthesis and N2 activation. Any evidence for such a route to phenyl cations is indirect,
with uncertainty remaining about the possible mechanism. Here, ultrafast
transient absorption spectroscopy of UV-excited (λ = 240 and
270 nm) chlorobenzene solutions in fluorinated (perfluorohexane) and
protic (ethanol and 2,2,2-trifluoroethanol) solvents reveals a broad
electronic absorption band centered at 540 nm that is assigned to
an isomer of chlorobenzene with both charge-separated and triplet-spin
carbene character. This spectroscopic feature is weaker, or absent,
when experiments are conducted in cyclohexane. The intermediate isomer
of chlorobenzene has a solvent-dependent lifetime of 30–110
ps, determined by reaction with the solvent or quenching to a lower-lying
singlet state. Evidence is presented for dissociation to ortho-benzyne, but the intermediate could also be a precursor to phenyl
cation formation.
Collapse
Affiliation(s)
- Min-Hsien Kao
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Andrew J Orr-Ewing
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, United Kingdom
| |
Collapse
|
7
|
Sensing the ortho Positions in C6Cl6 and C6H4Cl2 from Cl2− Formation upon Molecular Reduction. Molecules 2022; 27:molecules27154820. [PMID: 35956769 PMCID: PMC9369944 DOI: 10.3390/molecules27154820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 07/22/2022] [Accepted: 07/25/2022] [Indexed: 11/17/2022] Open
Abstract
The geometrical effect of chlorine atom positions in polyatomic molecules after capturing a low-energy electron is shown to be a prevalent mechanism yielding Cl2−. In this work, we investigated hexachlorobenzene reduction in electron transfer experiments to determine the role of chlorine atom positions around the aromatic ring, and compared our results with those using ortho-, meta- and para-dichlorobenzene molecules. This was achieved by combining gas-phase experiments to determine the reaction threshold by means of mass spectrometry together with quantum chemical calculations. We also observed that Cl2− formation can only occur in 1,2-C6H4Cl2, where the two closest C–Cl bonds are cleaved while the chlorine atoms are brought together within the ring framework due to excess energy dissipation. These results show that a strong coupling between electronic and C–Cl bending motion is responsible for a positional isomeric effect, where molecular recognition is a determining factor in chlorine anion formation.
Collapse
|
8
|
Kreis C, Hollenstein U, Merkt F. Threshold-ion-pair-production spectroscopy of H 2S and D 2S. Mol Phys 2022. [DOI: 10.1080/00268976.2022.2071349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- C. Kreis
- Laboratory of Physical Chemistry, ETH Zurich, Zurich, Switzerland
| | - U. Hollenstein
- Laboratory of Physical Chemistry, ETH Zurich, Zurich, Switzerland
| | - F. Merkt
- Laboratory of Physical Chemistry, ETH Zurich, Zurich, Switzerland
| |
Collapse
|
9
|
Donovan RJ, Kirrander A, Lawley KP. Heavy Rydberg and ion-pair states: chemistry, spectroscopy and theory. INT REV PHYS CHEM 2022. [DOI: 10.1080/0144235x.2022.2077024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Affiliation(s)
- Robert J. Donovan
- School of Chemistry, University of Edinburgh, Edinburgh, United Kingdom
| | - Adam Kirrander
- School of Chemistry, University of Edinburgh, Edinburgh, United Kingdom
| | - Kenneth P. Lawley
- School of Chemistry, University of Edinburgh, Edinburgh, United Kingdom
| |
Collapse
|
10
|
Bista D, Sengupta T, Reber AC, Khanna SN. A Magnetic Superatomic Dimer with an Intense Internal Electric Dipole Moment. J Phys Chem A 2021; 125:816-824. [DOI: 10.1021/acs.jpca.0c10262] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Dinesh Bista
- Department of Physics, Virginia Commonwealth University, Richmond, Virginia 23284-2000, United States
| | - Turbasu Sengupta
- Department of Physics, Virginia Commonwealth University, Richmond, Virginia 23284-2000, United States
| | - Arthur C. Reber
- Department of Physics, Virginia Commonwealth University, Richmond, Virginia 23284-2000, United States
| | - Shiv N. Khanna
- Department of Physics, Virginia Commonwealth University, Richmond, Virginia 23284-2000, United States
| |
Collapse
|
11
|
Lozano AI, Maioli LS, Pamplona B, Romero J, Mendes M, Ferreira da Silva F, Kossoski F, Probst M, Süβ D, Bettega MHF, García G, Limão-Vieira P. Selective bond breaking of halothane induced by electron transfer in potassium collisions. Phys Chem Chem Phys 2020; 22:23837-23846. [PMID: 33073277 DOI: 10.1039/d0cp02570d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We present novel experimental results of negative ion formation of halothane (C2HBrClF3) upon electron transfer from hyperthermal neutral potassium atoms (K°) in the collision energy range of 8-1000 eV. The experiments were performed in a crossed molecular beam setup allowing a comprehensive analysis of the time-of-flight (TOF) mass negative ions fragmentation pattern and a detailed knowledge of the collision dynamics in the energy range investigated. Such TOF mass spectra data show that the only negative ions formed are Br-, Cl- and F-, with a strong energy dependence in the low-energy collision region, with the bromine anion being the most abundant and sole fragment at the lowest collision energy probed. In addition, potassium cation (K+) energy loss spectra in the forward scattering direction were obtained in a hemispherical energy analyser at different K° impact energies. In order to support our experimental findings, ab initio quantum chemical calculations have been performed to help interpret the role of the electronic structure of halothane. Potential energy curves were obtained along the C-X (X = Br, Cl) coordinate to lend support to the dissociation processes yielding anion formation.
Collapse
Affiliation(s)
- A I Lozano
- Atomic and Molecular Collisions Laboratory, CEFITEC, Department of Physics, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
McNeill AS, Peterson KA, Dixon DA. Polarizabilities of neutral atoms and atomic ions with a noble gas electron configuration. J Chem Phys 2020; 153:174304. [DOI: 10.1063/5.0026876] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Ashley S. McNeill
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, Alabama 35487, USA
| | - Kirk A. Peterson
- Department of Chemistry, Washington State University, Pullman, Washington 99164, USA
| | - David A. Dixon
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, Alabama 35487, USA
| |
Collapse
|
13
|
Geweke J, Wodtke AM. Vibrationally inelastic scattering of HCl from Ag(111). J Chem Phys 2020; 153:164703. [DOI: 10.1063/5.0026228] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Jan Geweke
- Department of Dynamics at Surfaces, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
- Max-Planck-EPFL Center for Molecular Nanoscience and Technology, Institute of Chemical Sciences and Engineering (ISIC), Station 6, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
- Institute for Physical Chemistry, Georg-August University of Göttingen, 37077 Göttingen, Germany
| | - Alec M. Wodtke
- Department of Dynamics at Surfaces, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
- Max-Planck-EPFL Center for Molecular Nanoscience and Technology, Institute of Chemical Sciences and Engineering (ISIC), Station 6, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
- Institute for Physical Chemistry, Georg-August University of Göttingen, 37077 Göttingen, Germany
- International Center for Advanced Studies of Energy Conversion, Georg-August University of Göttingen, 37077 Göttingen, Germany
| |
Collapse
|
14
|
Christensen EG, Steele RP. Stepwise Activation of Water by Open-Shell Interactions, Cl(H 2O) n=4–8,17. J Phys Chem A 2020; 124:3417-3437. [DOI: 10.1021/acs.jpca.0c01544] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Elizabeth G. Christensen
- Department of Chemistry and Henry Eyring Center for Theoretical Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, United States
| | - Ryan P. Steele
- Department of Chemistry and Henry Eyring Center for Theoretical Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, United States
| |
Collapse
|
15
|
Hamade Y, El Sobbahi A. Theoretical study of the electronic structure of mono-chloride of lanthanum molecule including spin-orbit coupling effect. J Mol Model 2018; 24:100. [PMID: 29569165 DOI: 10.1007/s00894-018-3579-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 01/05/2018] [Indexed: 11/26/2022]
Abstract
Our investigation is devoted to the theoretical study of the low-lying electronic structure of the LaCl molecule by using ab initio quantum methods. We are concerned with several methods such as the complete active space-self consistent field (CAS-SCF) and the multi reference of configuration interaction (MRCI + Q) methods. These methods are applied for the purpose of drawing the potential energy curves (PECs) and calculating the molecular spectroscopic constants for a given number of electronic states of singlet and triplet multiplicity. We count 26 2S+ 1 Λ(±) electronic states located below 24,000 cm- 1 neglecting the spin-orbit effects and 47 Ω(±) components taken into consideration these effects. Our calculations are performed via the quantum ab initio package MOLPRO (Werner and Knowles 2000). Graphical Abstract A new set of low-lying electronic states on the theoretical energetic level diagram for the LaCl molecule among the first four lanthanum monhalides.
Collapse
Affiliation(s)
- Yaman Hamade
- MQMM lab associated to the research platformTR2N, Lebanese University, faculty of Engineering branch III, Rafic Hariri Campus-Hadath, Lebanon.
- Petrochemistry Department, Faculty of Engineering III, Lebanese University, Beirut, Lebanon.
| | - Ahmad El Sobbahi
- Faculty of Sciences I, Lebanese University, Rafic Hariri Campus-Hadath, Lebanon
| |
Collapse
|
16
|
Himmel D, Radtke V, Butschke B, Krossing I. Grundlegende Bemerkungen zur Azidität. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201709057] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Daniel Himmel
- Institut für Anorganische und Analytische Chemie, und Freiburger Materialforschungszentrum (FMF); Universität Freiburg; Albertstraße 21 79104 Freiburg Deutschland
| | - Valentin Radtke
- Institut für Anorganische und Analytische Chemie, und Freiburger Materialforschungszentrum (FMF); Universität Freiburg; Albertstraße 21 79104 Freiburg Deutschland
| | - Burkhard Butschke
- Institut für Anorganische und Analytische Chemie, und Freiburger Materialforschungszentrum (FMF); Universität Freiburg; Albertstraße 21 79104 Freiburg Deutschland
| | - Ingo Krossing
- Institut für Anorganische und Analytische Chemie, und Freiburger Materialforschungszentrum (FMF); Universität Freiburg; Albertstraße 21 79104 Freiburg Deutschland
| |
Collapse
|
17
|
Himmel D, Radtke V, Butschke B, Krossing I. Basic Remarks on Acidity. Angew Chem Int Ed Engl 2018; 57:4386-4411. [PMID: 29171707 DOI: 10.1002/anie.201709057] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 11/16/2017] [Indexed: 12/21/2022]
Abstract
This Review provides a unified view on Brønsted acidity. For this purpose, a brief overview of the concepts acidity, acid strengths, and pH value is given, including problems, proposed solutions, and the use of the pHabs /pHabsH2O scale as a unifying concept. Thereafter, some examples of the accessibility and application of unified pHabs values are given. The Review is rounded off with the analogy of acid-base chemistry to redox chemistry with the introduction of the unified redox scale peabs . The combination of pHabs and peabs values in the protoelectric potential map (PPM), as elaborated in ongoing studies on the thermochemistry of single ions, provides a means to classify and to compare all possible acid-base/redox reactions in a medium-independent and, thus, unified fashion.
Collapse
Affiliation(s)
- Daniel Himmel
- Institut für Anorganische und Analytische Chemie and Freiburger Materialforschungszentrum (FMF), Universität Freiburg, Albertstrasse 21, 79104, Freiburg, Germany
| | - Valentin Radtke
- Institut für Anorganische und Analytische Chemie and Freiburger Materialforschungszentrum (FMF), Universität Freiburg, Albertstrasse 21, 79104, Freiburg, Germany
| | - Burkhard Butschke
- Institut für Anorganische und Analytische Chemie and Freiburger Materialforschungszentrum (FMF), Universität Freiburg, Albertstrasse 21, 79104, Freiburg, Germany
| | - Ingo Krossing
- Institut für Anorganische und Analytische Chemie and Freiburger Materialforschungszentrum (FMF), Universität Freiburg, Albertstrasse 21, 79104, Freiburg, Germany
| |
Collapse
|
18
|
Corinti D, Gregori B, Guidoni L, Scuderi D, McMahon TB, Chiavarino B, Fornarini S, Crestoni ME. Complexation of halide ions to tyrosine: role of non-covalent interactions evidenced by IRMPD spectroscopy. Phys Chem Chem Phys 2018; 20:4429-4441. [PMID: 29372198 DOI: 10.1039/c7cp06657k] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The binding motifs in the halide adducts with tyrosine ([Tyr + X]-, X = Cl, Br, I) have been investigated and compared with the analogues with 3-nitrotyrosine (nitroTyr), a biomarker of protein nitration, in a solvent-free environment by mass-selected infrared multiple photon dissociation (IRMPD) spectroscopy over two IR frequency ranges, namely 950-1950 and 2800-3700 cm-1. Extensive quantum chemical calculations at B3LYP, B3LYP-D3 and MP2 levels of theory have been performed using the 6-311++G(d,p) basis set to determine the geometry, relative energy and vibrational properties of likely isomers and interpret the measured spectra. A diagnostic carbonyl stretching band at ∼1720 cm-1 from the intact carboxylic group characterizes the IRMPD spectra of both [Tyr + X]- and [nitroTyr + X]-, revealing that the canonical isomers (maintaining intact amino and carboxylic functions) are the prevalent structures. The spectroscopic evidence reveals the presence of multiple non-covalent forms. The halide complexes of tyrosine conform to a mixture of plane and phenol isomers. The contribution of phenol-bound isomers is sensitive to anion size, increasing from chloride to iodide, consistent with the decreasing basicity of the halide, with relative amounts depending on the relative energies of the respective structures. The stability of the most favorable phenol isomer with respect to the reference plane geometry is in fact 1.3, -2.1, -6.8 kJ mol-1, for X = Cl, Br, I, respectively. The change in π-acidity by ring nitration also stabilizes anion-π interactions yielding ring isomers for [nitroTyr + X]-, where the anion is placed above the face of the aromatic ring.
Collapse
Affiliation(s)
- Davide Corinti
- Dipartimento di Chimica e Tecnologie del Farmaco, Università di Roma "La Sapienza", P.le A. Moro 5, I-00185 Roma, Italy.
| | | | | | | | | | | | | | | |
Collapse
|
19
|
Gaiffe G, Bridoux MC, Costanza C, Cole RB. A systematic tandem mass spectrometric study of anion attachment for improved detection and acidity evaluation of nitrogen-rich energetic compounds. JOURNAL OF MASS SPECTROMETRY : JMS 2018; 53:21-29. [PMID: 28960805 DOI: 10.1002/jms.4034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 09/20/2017] [Accepted: 09/20/2017] [Indexed: 06/07/2023]
Abstract
The development of rapid, efficient, and reliable detection methods for the characterization of energetic compounds is of high importance to security forces concerned with terrorist threats. With a mass spectrometric approach, characteristic ions can be produced by attaching anions to analyte molecules in the negative ion mode of electrospray ionization mass spectrometry (ESI-MS). Under optimized conditions, formed anionic adducts can be detected with higher sensitivities as compared with the deprotonated molecules. Fundamental aspects pertaining to the formation of anionic adducts of 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX), 1,3,5-trinitro-1,3,5-triazinane (RDX), pentaerythritol tetranitrate (PETN), nitroglycerin (NG), and 1,3,5-trinitroso-1,3,5-triazinane energetic (R-salt) compounds using various anions have been systematically studied by ESI-MS and ESI tandem mass spectrometry (collision-induced dissociation) experiments. Bracketing method results show that the gas-phase acidities of PETN, RDX, and HMX fall between those of HF and acetic acid. Moreover, PETN and RDX are each less acidic than HMX in the gas phase. Nitroglycerin was found to be the most acidic among the nitrogen-rich explosives studied. The ensemble of bracketing results allows the construction of the following ranking of gas-phase acidities: PETN (1530-1458 kJ/mol) > RDX (approximately 1458 kJ/mol) > HMX (approximately 1433 kJ/mol) > nitroglycerin (1427-1327.8 kJ/mol).
Collapse
Affiliation(s)
- Gabriel Gaiffe
- Institut Parisien de Chimie Moléculaire (IPCM), Sorbonne Universités, UPMC Univ Paris 06, 4 Place Jussieu, 75252, Paris Cedex 05, France
| | | | - Christine Costanza
- Laboratoire Central de la Préfecture de Police, 39 bis rue de Dantzig, 75015, Paris, France
| | - Richard B Cole
- Institut Parisien de Chimie Moléculaire (IPCM), Sorbonne Universités, UPMC Univ Paris 06, 4 Place Jussieu, 75252, Paris Cedex 05, France
| |
Collapse
|
20
|
Kelly JT, Knorke H, Asmis KR. Isolating the Isomeric Hydrogen Bonding Signatures of the Cyanide-Water Complex by Cryogenic Ion Trap Vibrational Spectroscopy. J Phys Chem Lett 2017; 8:5349-5354. [PMID: 28976759 DOI: 10.1021/acs.jpclett.7b02263] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The vibrational spectroscopy of the cyanide-water complex and its fully deuterated isotopologue is studied in the spectral range from 800 to 3800 cm-1. Infrared/infrared double-resonance population labeling spectroscopy of the cryogenically cooled, messenger-tagged complexes isolates the spectral signature of the two quasi-isoenergetic, singly hydrogen-bonded isomers HOH···NC- and HOH···CN-. The infrared photodissociation spectra are assigned based on a comparison to simulated anharmonic spectra. Infrared multiple photon dissociation spectra in the temperature range from 6 to 300 K confirm the stability of the two isomers at lower temperatures and provide evidence for a considerably more dynamic structure, also involving doubly hydrogen-bonded configurations, at higher internal energies. The observed red shifts ΔνOH of the hydrogen-bonded O-H stretches, 671 cm-1 (HOH···NC-) and 812 cm-1 (HOH···CN-), confirm the universal correlation of ΔνOH with the corresponding proton affinities.
Collapse
Affiliation(s)
- John T Kelly
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig , Linnéstraße 2, D-04103 Leipzig, Germany
| | - Harald Knorke
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig , Linnéstraße 2, D-04103 Leipzig, Germany
| | - Knut R Asmis
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig , Linnéstraße 2, D-04103 Leipzig, Germany
| |
Collapse
|
21
|
Kuzmina O, Hassan NH, Patel L, Ashworth C, Bakis E, White AJP, Hunt PA, Welton T. The impact of ionic liquids on the coordination of anions with solvatochromic copper complexes. Dalton Trans 2017; 46:12185-12200. [DOI: 10.1039/c7dt02372c] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Traditionally weakly associating anions demonstrate a stronger than expected level of coordinating ability within ILs.
Collapse
Affiliation(s)
- O. Kuzmina
- Department of Chemistry
- Imperial College London
- London SW7 2AZ
- UK
| | - N. H. Hassan
- Department of Chemistry
- Imperial College London
- London SW7 2AZ
- UK
- School of Chemical Sciences and Food Technology
| | - L. Patel
- Department of Chemistry
- Imperial College London
- London SW7 2AZ
- UK
| | - C. Ashworth
- Department of Chemistry
- Imperial College London
- London SW7 2AZ
- UK
| | - E. Bakis
- Department of Chemistry
- Imperial College London
- London SW7 2AZ
- UK
| | - A. J. P. White
- Department of Chemistry
- Imperial College London
- London SW7 2AZ
- UK
| | - P. A. Hunt
- Department of Chemistry
- Imperial College London
- London SW7 2AZ
- UK
| | - T. Welton
- Department of Chemistry
- Imperial College London
- London SW7 2AZ
- UK
| |
Collapse
|
22
|
Seshadri V, Westmoreland PR. Roles of hydroxyls in the noncatalytic and catalyzed formation of levoglucosan from glucose. Catal Today 2016. [DOI: 10.1016/j.cattod.2015.10.033] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
23
|
Jeong HJ, Kim JJ, Kang H. Laser Desorption of Tryptophan from Tryptophan-HCl Salt on a Graphite Substrate. B KOREAN CHEM SOC 2016. [DOI: 10.1002/bkcs.10678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Hae Jun Jeong
- Department of Chemistry; Ajou University; Suwon 16499 Korea
| | - Jeong Jin Kim
- Department of Chemistry; Ajou University; Suwon 16499 Korea
| | - Hyuk Kang
- Department of Chemistry; Ajou University; Suwon 16499 Korea
| |
Collapse
|
24
|
Kozole J, Levine LA, Tomlinson-Phillips J, Stairs JR. Gas phase ion chemistry of an ion mobility spectrometry based explosive trace detector elucidated by tandem mass spectrometry. Talanta 2015; 140:10-19. [PMID: 26048817 DOI: 10.1016/j.talanta.2015.03.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 03/01/2015] [Accepted: 03/02/2015] [Indexed: 11/26/2022]
Abstract
The gas phase ion chemistry for an ion mobility spectrometer (IMS) based explosive detector has been elucidated using tandem mass spectrometry. The IMS system, which is operated with hexachloroethane and isobutyramide reagent gases and an ion shutter type gating scheme, is connected to the atmospheric pressure interface of a triple quadrupole mass spectrometer (MS/MS). Product ion masses, daughter ion masses, and reduced mobility values for a collection of nitro, nitrate, and peroxide explosives measured with the IMS/MS/MS instrument are reported. The mass and mobility data together with targeted isotopic labeling experiments and information about sample composition and reaction environment are leveraged to propose molecular formulas, structures, and ionization pathways for the various product ions. The major product ions are identified as [DNT-H](-) for DNT, [TNT-H](-) for TNT, [RDX+Cl](-) and [RDX+NO2](-) for RDX, [HMX+Cl](-) and [HMX+NO2](-) for HMX, [NO3](-) for EGDN, [NG+Cl](-) and [NG+NO3](-) for NG, [PETN+Cl](-) and [PETN+NO3](-) for PETN, [HNO3+NO3](-) for NH4NO3, [NO2](-) for DMNB, [HMTD-NC3H6O3+H+Cl](-) and [HMTD+H-CH2O-H2O2](+) for HMTD, and [(CH3)3CO2](+) for TATP. In general, the product ions identified for the IMS system studied here are consistent with the product ions reported previously for an ion trap mobility spectrometer (ITMS) based explosive trace detector, which is operated with dichloromethane and ammonia reagent gases and an ion trap type gating scheme. Differences between the explosive trace detectors include the [NG+Cl](-) and [PETN+Cl](-) product ions being major ions in the IMS system compared to minor ions in the ITMS system as well as the major product ion for TATP being [(CH3)3CO2](+) for the IMS system and [(CH3)2CNH2](+) for the ITMS system.
Collapse
Affiliation(s)
- Joseph Kozole
- U.S. Department of Homeland Security, Science & Technology Directorate, Transportation Security Laboratory, Atlantic City International Airport, NJ, United States
| | - Lauren A Levine
- Kutztown University, Department of Physical Sciences, Kutztown, PA, United States
| | - Jill Tomlinson-Phillips
- U.S. Department of Homeland Security, Science & Technology Directorate, Transportation Security Laboratory, Atlantic City International Airport, NJ, United States
| | - Jason R Stairs
- U.S. Department of Homeland Security, Science & Technology Directorate, Transportation Security Laboratory, Atlantic City International Airport, NJ, United States.
| |
Collapse
|
25
|
Thomas MC, Kirk BB, Altvater J, Blanksby SJ, Nette GW. Formation and fragmentation of unsaturated fatty acid [M - 2H + Na]- ions: stabilized carbanions for charge-directed fragmentation. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2014; 25:237-247. [PMID: 24338213 DOI: 10.1007/s13361-013-0760-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Revised: 09/20/2013] [Accepted: 09/24/2013] [Indexed: 06/03/2023]
Abstract
Fatty acids are long-chain carboxylic acids that readily produce [M - H](-) ions upon negative ion electrospray ionization (ESI) and cationic complexes with alkali, alkaline earth, and transition metals in positive ion ESI. In contrast, only one anionic monomeric fatty acid-metal ion complex has been reported in the literature, namely [M - 2H + Fe(II)Cl](-). In this manuscript, we present two methods to form anionic unsaturated fatty acid-sodium ion complexes (i.e., [M - 2H + Na](-)). We find that these ions may be generated efficiently by two distinct methods: (1) negative ion ESI of a methanolic solution containing the fatty acid and sodium fluoride forming an [M - H + NaF](-) ion. Subsequent collision-induced dissociation (CID) results in the desired [M - 2H + Na](-) ion via the neutral loss of HF. (2) Direct formation of the [M - 2H + Na](-) ion by negative ion ESI of a methanolic solution containing the fatty acid and sodium hydroxide or bicarbonate. In addition to deprotonation of the carboxylic acid moiety, formation of [M - 2H + Na](-) ions requires the removal of a proton from the fatty acid acyl chain. We propose that this deprotonation occurs at the bis-allylic position(s) of polyunsaturated fatty acids resulting in the formation of a resonance-stabilized carbanion. This proposal is supported by ab initio calculations, which reveal that removal of a proton from the bis-allylic position, followed by neutral loss of HX (where X = F(-) and (-)OH), is the lowest energy dissociation pathway.
Collapse
Affiliation(s)
- Michael C Thomas
- Independent Marine Biochemistry Research, Moreton Bay Research Station, Dunwich, Qld, 4183, Australia,
| | | | | | | | | |
Collapse
|
26
|
Wick CD. HCl Accommodation, Dissociation, and Propensity for the Surface of Water. J Phys Chem A 2013; 117:12459-67. [DOI: 10.1021/jp4084212] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Collin D. Wick
- Louisiana Tech University, P.O. Box 10348, Ruston, Louisiana 71270, United States
| |
Collapse
|
27
|
Díaz-Tinoco M, Romero J, Ortiz JV, Reyes A, Flores-Moreno R. A generalized any-particle propagator theory: Prediction of proton affinities and acidity properties with the proton propagator. J Chem Phys 2013; 138:194108. [DOI: 10.1063/1.4805030] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
28
|
Chu G, Chen J, Liu F, Shan X, Sheng L, Xu Y, Tian S. Positive and negative photoion spectroscopy study of C 2Cl 4. Mol Phys 2013. [DOI: 10.1080/00268976.2012.728256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
29
|
O’Reilly RJ, Karton A, Radom L. Effect of Substituents on the Preferred Modes of One-Electron Reductive Cleavage of N–Cl and N–Br Bonds. J Phys Chem A 2013; 117:460-72. [DOI: 10.1021/jp310048f] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Robert J. O’Reilly
- School of Chemistry and ARC Centre of Excellence for Free Radical Chemistry and Biotechnology, University of Sydney, Sydney, NSW 2006, Australia
- School of Chemistry, University of Tasmania, Private Bag
75, Hobart, TAS 7001, Australia
| | - Amir Karton
- School of Chemistry and ARC Centre of Excellence for Free Radical Chemistry and Biotechnology, University of Sydney, Sydney, NSW 2006, Australia
| | - Leo Radom
- School of Chemistry and ARC Centre of Excellence for Free Radical Chemistry and Biotechnology, University of Sydney, Sydney, NSW 2006, Australia
| |
Collapse
|
30
|
Zhang J, Harthcock C, Kong W. Resonantly Enhanced Multiphoton Ionization and Zero Kinetic Energy Photoelectron Spectroscopy of Chrysene: A Comparison with Tetracene. J Phys Chem A 2012; 116:7016-22. [DOI: 10.1021/jp303323e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Jie Zhang
- Department
of Chemistry, Oregon State University, Corvallis, Oregon 97331-4003, United States
| | - Colin Harthcock
- Department
of Chemistry, Oregon State University, Corvallis, Oregon 97331-4003, United States
| | - Wei Kong
- Department
of Chemistry, Oregon State University, Corvallis, Oregon 97331-4003, United States
| |
Collapse
|
31
|
Gąszowski D, Ilczyszyn M. Does hydrogen bonding to xenon affect its 129Xe NMR chemical shift? Computational study on selected Brønsted acid–xenon complexes. Chem Phys Lett 2012. [DOI: 10.1016/j.cplett.2012.04.043] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
32
|
De Vleeschouwer F, Yang W, Beratan DN, Geerlings P, De Proft F. Inverse design of molecules with optimal reactivity properties: acidity of 2-naphthol derivatives. Phys Chem Chem Phys 2012; 14:16002-13. [DOI: 10.1039/c2cp42623d] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
33
|
Xu YF, Tian SX, Chen L, Liu FY, Sheng L. Positive and negative photoion spectroscopy study of monochlorothiophenes. J Phys Chem A 2011; 115:10920-9. [PMID: 21888433 DOI: 10.1021/jp205401k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Photolysis dynamics of monochlorothiophenes (2- and 3-chlorothiophenes) is investigated using positive and negative photoion mass spectrometry combined with the synchrotron vacuum ultraviolet radiation. A dozen of the daughter cations are observed in the time-of-flight mass spectra, and their appearance energies are determined by the photoion efficiency spectroscopy measurements. At the energetic threshold, the concerted process rather than a stepwise reaction for C(4)H(3)SCl(+) → C(2)HSCl(+) + C(2)H(2) and the ring-open isomers of the dehydrogenated thiophene cations (C(4)H(3)S(+) and C(4)H(2)S(+)) formed in C(4)H(3)SCl(+) → C(4)H(3)S(+) + Cl and C(4)H(2)S(+) + HCl are proposed on the basis of the B3LYP/6-311+G(3df,3pd) calculations. The chlorine anion (Cl(-)) is observed as the product of the photoion-pair dissociations in the energy range of 10.70-22.00 eV. A set of valence-to-Rydberg state transitions 12a' → np (n = 6, 7, 8, 9, 10, etc.) and several series of vibrational excitations are tentatively assigned in the Cl(-) spectrum of 2-chlorothiophene in the lower energy range of 10.90-12.00 eV.
Collapse
Affiliation(s)
- Yun-Feng Xu
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | | | | | | | | |
Collapse
|
34
|
Modelli A, Bolognesi P, Avaldi L. Temporary anion states of pyrimidine and halopyrimidines. J Phys Chem A 2011; 115:10775-82. [PMID: 21875136 DOI: 10.1021/jp206559d] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The empty-level electronic structures of pyrimidine and its 2-chloro, 2-bromo, and 5-bromo derivatives have been studied with electron transmission spectroscopy (ETS) and dissociative electron attachment spectroscopy (DEAS) in the 0-5 eV energy range. The spectral features were assigned to the corresponding anion states with the support of theoretical calculations at the ab initio and density functional theory levels. The empty orbital energies obtained by simple Koopmans' theorem calculations, scaled with empirical equations, quantitatively reproduced the energies of vertical electron attachment to π* and σ* empty orbitals measured in the ET spectra and predicted vertical electron affinities close to zero for the three halo derivatives. The total anion currents of the halo derivatives, measured at the walls of the collision chamber as a function of the impact electron energy, presented intense maxima below 0.5 eV. The mass-selected spectra showed that, in this energy, range the total anion current is essentially due to halide fragment anions. The DEA cross sections of the bromo derivatives were found to be about six times larger than that of the chloro derivative. The absolute cross sections at incident electron energies close to zero were evaluated to be 10(-16)-10(-15) cm(2).
Collapse
Affiliation(s)
- Alberto Modelli
- Dipartimento di Chimica G. Ciamician, Università di Bologna, via Selmi 2, 40126 Bologna, Italy.
| | | | | |
Collapse
|
35
|
Chen LL, Tian SX, Xu YF, Chu GB, Liu FY, Shan XB, Sheng LS. Ion-Pair Photodissociation of Trichloromonofluoromethane. CHINESE J CHEM PHYS 2011. [DOI: 10.1088/1674-0068/24/03/261-266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
36
|
Chen LL, Xu YF, Feng Q, Tian SX, Liu FY, Shan XB, Sheng LS. Vacuum ultraviolet negative photoion spectroscopy of chloroform. J Phys Chem A 2011; 115:4248-54. [PMID: 21456568 DOI: 10.1021/jp2000927] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Negative ions Cl(-), Cl(2)(-), CCl(-), CHCl(-), and CCl(2)(-) are observed in vacuum-ultraviolet ion-pair photodissociations of chloroform (CCl(3)H) using the Hefei synchrotron radiation facility, and their ion production efficiency curves are recorded in the photon energy range of 10.00-21.50 eV. Two similar spectra of the isotope anions (35)Cl(-) and (37)Cl(-) indicate the following: Besides the strong bands corresponding to the electron transitions from valence to Rydberg orbitals converging to the ionic states, some additional peaks can be assigned with the energetically accessible multibody fragmentations; a distinct peak at photon energy 14.55 eV may be due to a cascade process (namely, the Cl(2) neutral fragment at the highly excited state D'2(3)Π(g) may be produced in the photodissociation of CCl(3)H, and then the Cl(-) anions are produced in the pulsed-field induced ion-pair dissociations of Cl(2) (D'2(3)Π(g))); two vibrational excitation progressions, nν(2)(+) and nν(2)(+) + ν(3)(+), and nν(4)(+) and nν(4)(+) + ν(2)(+), are observed around C̃ (2)E and D̃ (2)E ionic states, respectively. The enthalpies of the multibody fragmentations to Cl(2)(-), CCl(-), CHCl(-), and CCl(2)(-) are calculated with the thermochemistry data available in the literature, and these multibody ion-pair dissociation pathways are tentatively assigned in the respective anion production spectra.
Collapse
Affiliation(s)
- Liu-Li Chen
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui, China
| | | | | | | | | | | | | |
Collapse
|
37
|
Pattison DI, O'Reilly RJ, Skaff O, Radom L, Anderson RF, Davies MJ. One-electron reduction of N-chlorinated and N-brominated species is a source of radicals and bromine atom formation. Chem Res Toxicol 2011; 24:371-82. [PMID: 21344936 DOI: 10.1021/tx100325z] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Hypochlorous (HOCl) and hypobromous (HOBr) acids are strong bactericidal oxidants that are generated by the human immune system but are implicated in the development of many human inflammatory diseases (e.g., atherosclerosis, asthma). These oxidants react readily with sulfur- and nitrogen-containing nucleophiles, with the latter generating N-halogenated species (e.g., chloramines/bromamines (RR'NX; X = Cl, Br)) as initial products. Redox-active metal ions and superoxide radicals (O(2)(•-)) can reduce N-halogenated species to nitrogen- and carbon-centered radicals. N-Halogenated species and O(2)(•-) are generated simultaneously at sites of inflammation, but the significance of their interactions remains unclear. In the present study, rate constants for the reduction of N-halogenated amines, amides, and imides to model potential biological substrates have been determined. Hydrated electrons reduce these species with k(2) > 10(9) M(-1) s(-1), whereas O(2)(•-) reduced only N-halogenated imides with complex kinetics indicative of chain reactions. For N-bromoimides, heterolytic cleavage of the N-Br bond yielded bromine atoms (Br(•)), whereas for other substrates, N-centered radicals and Cl(-)/Br(-) were produced. High-level quantum chemical procedures have been used to calculate gas-phase electron affinities and aqueous solution reduction potentials. The effects of substituents on the electron affinities of aminyl, amidyl, and imidyl radicals are rationalized on the basis of differential effects on the stabilities of the radicals and anions. The calculated reduction potentials are consistent with the experimental observations, with Br(•) production predicted for N-bromosuccinimide, while halide ion formation is predicted in all other cases. These data suggest that interaction of N-halogenated species with O(2)(•-) may produce deleterious N-centered radicals and Br(•).
Collapse
|
38
|
Garkusha I, Fulara J, Nagy A, Maier JP. Electronic Transitions of Protonated Benzene and Fulvene, and of C6H7 Isomers in Neon Matrices. J Am Chem Soc 2010; 132:14979-85. [DOI: 10.1021/ja106470x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Iryna Garkusha
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Jan Fulara
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Adam Nagy
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - John P. Maier
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| |
Collapse
|
39
|
Rayne S, Forest K. Gas phase acidities and associated equilibrium isotope effects for selected main group mono- and polyhydrides, carbon acids, and oxyacids: A G4 and W1BD study. ACTA ACUST UNITED AC 2010. [DOI: 10.1016/j.theochem.2010.06.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
40
|
Rose RA, Greaves SJ, Orr-Ewing AJ. Velocity map imaging the dynamics of the reactions of Cl atoms with neopentane and tetramethylsilane. J Chem Phys 2010; 132:244312. [DOI: 10.1063/1.3447378] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
41
|
Jia X, Liu Y, Sun J, Sun H, Su Z, Pan X, Wang R. Theoretical Investigation of the Reactions of CF3CHFOCF3 with the OH Radical and Cl Atom. J Phys Chem A 2009; 114:417-24. [PMID: 19950919 DOI: 10.1021/jp908228h] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Xiujuan Jia
- Faculty of Chemistry, Institute of Functional Material Chemistry, Northeast Normal University, 130024 Changchun, People’s Republic of China, and Faculty of Physics, Aviation University of Air Force, 130022 Changchun, People’s Republic of China
| | - Youjun Liu
- Faculty of Chemistry, Institute of Functional Material Chemistry, Northeast Normal University, 130024 Changchun, People’s Republic of China, and Faculty of Physics, Aviation University of Air Force, 130022 Changchun, People’s Republic of China
| | - Jingyu Sun
- Faculty of Chemistry, Institute of Functional Material Chemistry, Northeast Normal University, 130024 Changchun, People’s Republic of China, and Faculty of Physics, Aviation University of Air Force, 130022 Changchun, People’s Republic of China
| | - Hao Sun
- Faculty of Chemistry, Institute of Functional Material Chemistry, Northeast Normal University, 130024 Changchun, People’s Republic of China, and Faculty of Physics, Aviation University of Air Force, 130022 Changchun, People’s Republic of China
| | - Zhongmin Su
- Faculty of Chemistry, Institute of Functional Material Chemistry, Northeast Normal University, 130024 Changchun, People’s Republic of China, and Faculty of Physics, Aviation University of Air Force, 130022 Changchun, People’s Republic of China
| | - Xiumei Pan
- Faculty of Chemistry, Institute of Functional Material Chemistry, Northeast Normal University, 130024 Changchun, People’s Republic of China, and Faculty of Physics, Aviation University of Air Force, 130022 Changchun, People’s Republic of China
| | - Rongshun Wang
- Faculty of Chemistry, Institute of Functional Material Chemistry, Northeast Normal University, 130024 Changchun, People’s Republic of China, and Faculty of Physics, Aviation University of Air Force, 130022 Changchun, People’s Republic of China
| |
Collapse
|
42
|
Wren SW, Vogelhuber KM, Ervin KM, Lineberger WC. The photoelectron spectrum of CCl2−: the convergence of theory and experiment after a decade of debate. Phys Chem Chem Phys 2009; 11:4745-53. [DOI: 10.1039/b822690c] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
43
|
Nava P, Carissan Y, Humbel S. Labile ligands on some Lewis super acids: a computational study. Phys Chem Chem Phys 2009; 11:7130-6. [DOI: 10.1039/b907229b] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
44
|
Pelc A, Halas S. Negative ion source for chlorine isotope ratio measurements. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2008; 22:3977-3982. [PMID: 19021131 DOI: 10.1002/rcm.3814] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A negative chlorine ion source has been designed and constructed. The source utilizes direct surface ionization of chloromethane gas on a hot metal filament. Four different alloys for the filament material were tested: W99Th1, W75Re25, Hf97.5Zr2.5 and Mo52.5Re47.5. We conclude that the best filament material is the MoRe alloy, for which the signal-to-noise ratio is optimal. The ion source is used for chlorine isotope ratio measurements with higher precision and sensitivity than the positive ionization source used previously. Inasmuch as only negative ions of the two isotopes of interest are observed, no corrections to the measured isotope ratio are necessary, and less rigously purified samples may be analyzed. The negative ion currents are considerably larger than positive ion currents obtained with an electron ionization source. This implies higher analytical precision (typically 0.005 permil) and sensitivity.
Collapse
Affiliation(s)
- Andrzej Pelc
- Mass Spectrometry Laboratory, Institute of Physics, Maria Curie-Skłodowska University, 20-031 Lublin, Poland.
| | | |
Collapse
|
45
|
de Petris G, Cartoni A, Rosi M, Troiani A. The HSSS Radical and the HSSS− Anion. J Phys Chem A 2008; 112:8471-7. [DOI: 10.1021/jp8055637] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Giulia de Petris
- Dipartimento di Chimica e Tecnologie del Farmaco, Università “La Sapienza”, Piazzale Aldo Moro 5, 00185 Rome, Italy, and Dipartimento di Ingegneria Civile ed Ambientale—Sezione Tecnologie Chimiche e Materiali per l’Ingegneria, ISTM-CNR—Università di Perugia, Via Duranti, I-06131, Perugia, Italy
| | - Antonella Cartoni
- Dipartimento di Chimica e Tecnologie del Farmaco, Università “La Sapienza”, Piazzale Aldo Moro 5, 00185 Rome, Italy, and Dipartimento di Ingegneria Civile ed Ambientale—Sezione Tecnologie Chimiche e Materiali per l’Ingegneria, ISTM-CNR—Università di Perugia, Via Duranti, I-06131, Perugia, Italy
| | - Marzio Rosi
- Dipartimento di Chimica e Tecnologie del Farmaco, Università “La Sapienza”, Piazzale Aldo Moro 5, 00185 Rome, Italy, and Dipartimento di Ingegneria Civile ed Ambientale—Sezione Tecnologie Chimiche e Materiali per l’Ingegneria, ISTM-CNR—Università di Perugia, Via Duranti, I-06131, Perugia, Italy
| | - Anna Troiani
- Dipartimento di Chimica e Tecnologie del Farmaco, Università “La Sapienza”, Piazzale Aldo Moro 5, 00185 Rome, Italy, and Dipartimento di Ingegneria Civile ed Ambientale—Sezione Tecnologie Chimiche e Materiali per l’Ingegneria, ISTM-CNR—Università di Perugia, Via Duranti, I-06131, Perugia, Italy
| |
Collapse
|
46
|
Valiev M, Bylaska EJ, Dupuis M, Tratnyek PG. Combined Quantum Mechanical and Molecular Mechanics Studies of the Electron-Transfer Reactions Involving Carbon Tetrachloride in Solution. J Phys Chem A 2008; 112:2713-20. [DOI: 10.1021/jp7104709] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Marat Valiev
- William R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington, 99352
| | - Eric J. Bylaska
- William R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington, 99352
| | - Michel Dupuis
- Fundamental Sciences Division, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352
| | - Paul G. Tratnyek
- OGI School of Science & Engineering, Oregon Health & Science University, 20000 Northwest Walker Road, Beaverton, Oregon 97006-8921
| |
Collapse
|
47
|
Romanescu C, Loock HP. Proton formation in 2+1 resonance enhanced multiphoton excitation of HCl and HBr via (Ω=0) Rydberg and ion-pair states. J Chem Phys 2007; 127:124304. [PMID: 17902900 DOI: 10.1063/1.2767259] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Molecular beam cooled HCl was state selected by two-photon excitation of the V (1) summation operator(0(+)) [v=9,11-13,15], E (1) summation operator(0(+)) [v=0], and g (3) summation operator(-)(0(+)) [v=0] states through either the Q(0) or Q(1) lines of the respective (1,3) summation operator(0(+))<--<--X (1) summation operator(0(+)) transition. Similarly, HBr was excited to the V (1) summation operator(0(+)) [v=m+3, m+5-m+8], E (1) summation operator(0(+)) [v=0], and H (1) summation operator(0(+)) [v=0] states through the Q(0) or Q(1) lines. Following absorption of a third photon, protons were formed by three different mechanisms and detected using velocity map imaging. (1) H(*)(n=2) was formed in coincidence with (2)P(i) halogen atoms and subsequently ionized. For HCl, photodissociation into H(*)(n=2)+Cl((2)P(12)) was dominant over the formation of Cl((2)P(32)) and was attributed to parallel excitation of the repulsive [(2) (2)Pi4llambda] superexcited (Omega=0) states. For HBr, the Br((2)P(32))Br((2)P(12)) ratio decreases with increasing excitation energy. This indicates that both the [(3) (2)Pi(12)5llambda] and the [B (2) summation operator5llambda] superexcited (Omega=0) states contribute to the formation of H(*)(n=2). (2) For selected intermediate states HCl was found to dissociate into the H(+)+Cl(-) ion pair with over 20% relative yield. A mechanism is proposed by which a bound [A (2) summation operatornlsigma] (1) summation operator(0(+)) superexcited state acts as a gateway state to dissociation into the ion pair. (3) For all intermediate states, protons were formed by dissociation of HX(+)[v(+)] following a parallel, DeltaOmega=0, excitation. The quantum yield for the dissociation process was obtained using previously reported photoionization efficiency data and was found to peak at v(+)=6-7 for HCl and v(+)=12 for HBr. This is consistent with excitation of the repulsive A(2) summation operator(12) and (2) (2)Pi states of HCl(+), and the (3) (2)Pi state of HBr(+). Rotational alignment of the Omega=0(+) intermediate states is evident from the angular distribution of the excited H(*)(n=2) photofragments. This effect has been observed previously and was used here to verify the reliability of the measured spatial anisotropy parameters.
Collapse
|
48
|
Zolot AM, Nesbitt DJ. Quantum state resolved scattering dynamics of F+HCl→HF(v,J)+Cl. J Chem Phys 2007; 127:114319. [PMID: 17887849 DOI: 10.1063/1.2770464] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
State-to-state reaction dynamics of the reaction F+HCl-->HF(v,J)+Cl have been studied under single-collision conditions using an intense discharge F atom source in crossed supersonic molecular beams at Ecom=4.3(1.3) kcal/mol. Nascent HF product is monitored by shot-noise limited direct infrared laser absorption, providing quantum state distributions as well as additional information on kinetic energy release from high resolution Dopplerimetry. The vibrational distributions are highly inverted, with 34(4)%, 44(2)%, and 8(1)% of the total population in vHF=1, 2, and 3, respectively, consistent with predominant energy release into the newly formed bond. However, there is a small [14(1)%] but significant formation channel into the vHF=0 ground state, which is directly detectable for the first time via direct absorption methods. Of particular dynamical interest, both the HF(v=2,J) and HF(v=1,J) populations exhibit strongly bimodal J distributions. These results differ significantly from previous flow and arrested-relaxation studies and may signal the presence of microscopic branching in the reaction dynamics.
Collapse
Affiliation(s)
- A M Zolot
- JILA, National Institute of Standards and Technology and Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, USA
| | | |
Collapse
|
49
|
Spectroscopic calculation of the bond-dissociation energy of CH bonds in fluoro derivatives of methane, ethane, ethene, propene, and benzene. J STRUCT CHEM+ 2007. [DOI: 10.1007/s10947-007-0061-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
50
|
Olleta AC, Lee HM, Kim KS. Ab initiostudy of hydrated potassium halides KX(H2O)1–6 (X=F,Cl,Br,I). J Chem Phys 2007; 126:144311. [PMID: 17444716 DOI: 10.1063/1.2715565] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The ionic dissociation of salts was examined with a theoretical study of KX (X=F,Cl,Br,I) hydrated by up to six water molecules KX(H2O)n (n=1-6). Calculations were done using the density functional theory and second order Møller-Plesset (MP2) perturbational theory. To provide more conclusive results, single point energy calculations using the coupled cluster theory with single, double, and perturbative triple excitations were performed on the MP2 optimized geometries. The dissociation feature of the salts was examined in terms of K-X bond lengths and K-X stretch frequencies. In general, the successive incorporation of water molecules to the cluster lengthens the K-X distance, and consequently the corresponding frequency decreases. Near 0 K, the KX salt ion pairs can be partly separated by more than five water molecules. The pentahydrated KX salt is partly dissociated, though these partly dissociated structures are almost isoenergetic to the undissociated ones for KFKCl. For the hexahydrated complexes, KF is undissociated, KClKBr is partly dissociated, and KI is dissociated (though this dissociated structure is nearly isoenergetic to a partly dissociated one). On the other hand, at room temperature, the penta- and hexahydrated undissociated structures which have less hydrogen bonds are likely to be more stable than the partly dissociated ones because of the entropy effect. Therefore, the dissociation at room temperature could take place for higher clusters than the hexahydrated ones.
Collapse
Affiliation(s)
- Adriana C Olleta
- Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, Pohang 790-784, Korea
| | | | | |
Collapse
|