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Hansen CS, Marchetti B, Karsili TNV, Ashfold MNR. Ultraviolet photodissociation of gas-phase transition metal complexes: dicarbonylcyclopentadienyliodoiron(II). Mol Phys 2021. [DOI: 10.1080/00268976.2020.1813343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Foley CD, Joalland B, Alavi ST, Suits AG. Mixed transitions in the UV photodissociation of propargyl chloride revealed by slice imaging and multireference ab initio calculations. Phys Chem Chem Phys 2018; 20:27474-27481. [DOI: 10.1039/c8cp04596h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Resonance-enhanced multiphoton ionization (REMPI) and DC slice imaging were used to detect photoproducts Cl (2P3/2), spin–orbit excited Cl* (2P1/2), and C3H3 in the photodissociation of propargyl chloride at 212 and 236 nm.
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Affiliation(s)
- Casey D. Foley
- Department of Chemistry
- University of Missouri
- Columbia
- USA
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Kapnas KM, Toulson BW, Foreman ES, Block SA, Hill JG, Murray C. UV photodissociation dynamics of CHI 2Cl and its role as a photolytic precursor for a chlorinated Criegee intermediate. Phys Chem Chem Phys 2017; 19:31039-31053. [PMID: 29160321 DOI: 10.1039/c7cp06532a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Photolysis of geminal diiodoalkanes in the presence of molecular oxygen has become an established route to the laboratory production of several Criegee intermediates, and such compounds also have marine sources. Here, we explore the role that the trihaloalkane, chlorodiiodomethane (CHI2Cl), may play as a photolytic precursor for the chlorinated Criegee intermediate ClCHOO. CHI2Cl has been synthesized and its UV absorption spectrum measured; relative to that of CH2I2 the spectrum is shifted to longer wavelength and the photolysis lifetime is calculated to be less than two minutes. The photodissociation dynamics have been investigated using DC slice imaging, probing ground state I and spin-orbit excited I* atoms with 2 + 1 REMPI and single-photon VUV ionization. Total translational energy distributions are bimodal for I atoms and unimodal for I*, with around 72% of the available energy partitioned in to the internal degrees of freedom of the CHICl radical product, independent of photolysis wavelength. A bond dissociation energy of D0 = 1.73 ± 0.11 eV is inferred from the wavelength dependence of the translational energy release, which is slightly weaker than typical C-I bonds. Analysis of the photofragment angular distributions indicate dissociation is prompt and occurs primarily via transitions to states of A'' symmetry. Complementary high-level MRCI calculations, including spin-orbit coupling, have been performed to characterize the excited states and confirm that states of A'' symmetry with highly mixed singlet and triplet character are predominantly responsible for the absorption spectrum. Transient absorption spectroscopy has been used to measure the absorption spectrum of ClCHOO produced from the reaction of CHICl with O2 over the range 345-440 nm. The absorption spectrum, tentatively assigned to the syn conformer, is at shorter wavelengths relative to that of CH2OO and shows far weaker vibrational structure.
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Affiliation(s)
- Kara M Kapnas
- Department of Chemistry, University of California, Irvine, Irvine, CA 92697, USA.
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Poullain SM, Chicharro DV, Rubio-Lago L, García-Vela A, Bañares L. A velocity-map imaging study of methyl non-resonant multiphoton ionization from the photodissociation of CH 3I in the A-band. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2017; 375:rsta.2016.0205. [PMID: 28320907 PMCID: PMC5360903 DOI: 10.1098/rsta.2016.0205] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/17/2016] [Indexed: 06/06/2023]
Abstract
Chemical reaction dynamics and, particularly, photodissociation in the gas phase are generally studied using pump-probe schemes where a first laser pulse induces the process under study and a second one detects the produced fragments. Providing an efficient detection of ro-vibrationally state-selected photofragments, the resonance enhanced multiphoton ionization (REMPI) technique is, without question, the most popular approach used for the probe step, while non-resonant multiphoton ionization (NRMPI) detection of the products is scarce. The main goal of this work is to test the sensitivity of the NRMPI technique to fragment vibrational distributions arising from molecular photodissociation processes. We revisit the well-known process of methyl iodide photodissociation in the A-band at around 280 nm, using the velocity-map imaging technique in conjunction with NRMPI of the methyl fragment. The detection wavelength, carefully selected to avoid any REMPI transition, was scanned between 325 and 335 nm seeking correlations between the different observables-the product vibrational, translational and angular distributions-and the excitation wavelength of the probe laser pulse. The experimental results have been discussed on the base of quantum dynamics calculations of photofragment vibrational populations carried out on available ab initio potential-energy surfaces using a four-dimensional model.This article is part of the themed issue 'Theoretical and computational studies of non-equilibrium and non-statistical dynamics in the gas phase, in the condensed phase and at interfaces'.
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Affiliation(s)
- Sonia Marggi Poullain
- Departamento de Química Física I (Unidad Asociada de I+D+I al CSIC), Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - David V Chicharro
- Departamento de Química Física I (Unidad Asociada de I+D+I al CSIC), Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Luis Rubio-Lago
- Departamento de Química Física I (Unidad Asociada de I+D+I al CSIC), Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | | | - Luis Bañares
- Departamento de Química Física I (Unidad Asociada de I+D+I al CSIC), Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
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Bhattacherjee A, Attar AR, Leone SR. Transition state region in the A-Band photodissociation of allyl iodide—A femtosecond extreme ultraviolet transient absorption study. J Chem Phys 2016; 144:124311. [DOI: 10.1063/1.4944930] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Aditi Bhattacherjee
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Andrew R. Attar
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Stephen R. Leone
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Department of Physics, University of California, Berkeley, California 94720, USA
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Toulson BW, Alaniz JP, Grant Hill J, Murray C. Near-UV photodissociation dynamics of CH2I2. Phys Chem Chem Phys 2016; 18:11091-103. [DOI: 10.1039/c6cp01063f] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The near-UV photodissociation dynamics of CH2I2has been investigated using a combination of velocity-map (slice) ion imaging andab initiocalculations characterizing the excited states.
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Affiliation(s)
| | | | - J. Grant Hill
- Department of Chemistry
- University of Sheffield
- Sheffield S3 7HF
- UK
| | - Craig Murray
- Department of Chemistry
- University of California, Irvine
- Irvine
- USA
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Gardiner SH, Lipciuc ML, Karsili TNV, Ashfold MNR, Vallance C. Dynamics of the A-band ultraviolet photodissociation of methyl iodide and ethyl iodide via velocity-map imaging with ‘universal’ detection. Phys Chem Chem Phys 2015; 17:4096-106. [DOI: 10.1039/c4cp04654d] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Universal ionization combined with velocity-map imaging allows a comprehensive investigation into the photodissociation dynamics of methyl iodide and ethyl iodide at a range of UV wavelengths within their A-bands.
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Affiliation(s)
- Sara H. Gardiner
- Department of Chemistry
- University of Oxford
- Chemistry Research Laboratory
- Oxford
- UK
| | - M. Laura Lipciuc
- Department of Chemistry
- University of Oxford
- Chemistry Research Laboratory
- Oxford
- UK
| | | | | | - Claire Vallance
- Department of Chemistry
- University of Oxford
- Chemistry Research Laboratory
- Oxford
- UK
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Sumida M, Hanada T, Yamasaki K, Kohguchi H. Photodissociation dynamics of C3H5I in the near-ultraviolet region. J Chem Phys 2014; 141:104316. [DOI: 10.1063/1.4894393] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Shubert VA, Rednic M, Pratt ST. Photodissociation of i-C3H7I within the A band and anisotropy-based decomposition of the translational energy distributions. J Chem Phys 2009; 130:134306. [PMID: 19355731 DOI: 10.1063/1.3094321] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The photodissociation of i-propyl iodide in the A absorption band was studied by using velocity map ion imaging following excitation between 304 and 253 nm. The translational energy distributions and translational energy dependence of the angular distributions of the I (2)P(3/2) and (2)P(1/2) photofragments were recorded as a function of the photodissociation wavelength. These distributions are used to decompose the i-C(3)H(7)+I (2)P(3/2) channel into contributions from two processes: Excitation to the (3)Q(0(+)) state followed by crossing onto the (1)Q(1) surface, and direct excitation to the (3)Q(1) surface followed by dissociation on that surface. As in the case of methyl iodide, the former process dominates; the latter process contributes only in the red wing of the absorption band, with its contribution peaking at approximately 287 nm with an absorption of approximately 1% of the band maximum. The data for the i-C(3)H(7)+I(*) (2)P(1/2) channel display a smooth behavior across the full energy range of the present study, and are consistent with direct excitation to the (3)Q(0(+)) surface followed by dissociation on that surface.
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Miao Y, Liu J. Assembly and electroanalytical performance of Prussian blue/polypyrrole composite nanoparticles synthesized by the reverse micelle method. SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS 2009; 10:025001. [PMID: 27877288 PMCID: PMC5090445 DOI: 10.1088/1468-6996/10/2/025001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2009] [Revised: 07/10/2009] [Accepted: 05/13/2009] [Indexed: 05/29/2023]
Abstract
We report on the characterization, assembly and electroanalytical performance of Prussian blue/polypyrrole (PBPPy) composite nanoparticles synthesized by the reverse micelle method. Scanning electron microscopy suggests the formation of nanosized PBPPy particles with diameters between 40 and 50 nm. Optical absorption confirms that the particles are composed of Prussian blue (PB) and polypyrrole. PB and PBPPy nanoparticles were anchored onto the surface of cysteine-modified Au electrodes. Cyclic voltammetry experiments show that PB- or PBPPy-modified electrodes exhibit intrinsic electrochemical properties and a high electrocatalytic activity towards H2O2. PBPPy-modified electrodes exhibit a higher sensitivity to H2O2 than PB-modified electrodes. A linear calibration curve in the concentration range 0.99 μM-8.26 mM H2O2 is constructed with a detection limit of 0.23 μM at a signal-to-noise ratio of 3. Excellent stability is observed for PBPPy-composite-nanoparticle-modified electrodes even in a pH 6 phosphate buffer solution with a high H2O2 concentration (0.99 mM). Glutaraldehyde and [Formula: see text] were also employed to immobilize glucose oxidase for the development of PBPPy-based biosensors. The results show that PBPPy composite nanoparticles can be used to develop oxidase-based biosensors.
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Affiliation(s)
| | - Jiwei Liu
- Laboratory of Biocatalysis and Biosensor, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004, People’s Republic of China
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