Project

Back to overview

Reactive Intermediates: Spectroscopic Investigations, and Quantum Chemical Modelling

English title Reactive Intermediates: Spectroscopic Investigations, and Quantum Chemical Modelling
Applicant Bally Thomas
Number 143410
Funding scheme Project funding (Div. I-III)
Research institution Département de Chimie Université de Fribourg
Institution of higher education University of Fribourg - FR
Main discipline Physical Chemistry
Start/End 01.10.2012 - 30.09.2014
Approved amount 109'252.00
Show all

All Disciplines (2)

Discipline
Physical Chemistry
Organic Chemistry

Keywords (6)

Matrix Isolation Spectroscopy; Radical Ions; Closed-shell ions; Radicals; Biradicals; Quantum chemical modelling

Lay Summary (English)

Lead
Lay summary
The ability to predict and control the outcome of chemical reactions, be it in biology or technology, frequently requires knowledge of the key reaction intermediates. The present research project focusses on the study of such fleeting species (primarily charged and uncharged radicals as well as closed-shell ions) under conditions where they persist sufficiently long to be probed by conventional spectroscopic means. To this end, suitable precursors are embedded in inert solid media at low temperature where the targeted reactive intermediates may then be generated by photolsis or radiolysis of these precursors. Another approach, mainly for radicals, consists in the pyrolysis of suitable precursors, which has the advantage that the two fragments end up in different matrix cavities and can thus not recombine. The electronic and vibrational spectra of the resulting species contain information that is used to confirm or reject hypotheses with regard to the identity and the structure of reactive intermediates. In addition, their reactivity can be probed by allowing them to rearrange, either by slightly raising the temperature or by exposing them to light at selected wavelengths, or by letting them engage in bimolecular reactions with suitable small reactants with which the host material is doped. A common feature of all projects is, that the experimental work is invariably accompanied by quantum chemical model calculations which serve on the one hand to interpret the spectroscopic observations and on the other hand to shed light on the reactivity of the observed species. Much of the insight obtained in this project arises from a synergy betwen experimental and theoretical approaches.
Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
Electron-Transfer-Induced Tautomerizations
Bally Thomas (2016), Electron-Transfer-Induced Tautomerizations, in Antonov Liudmil (ed.), Wiley-VCH, Weinheim, 75-94.
Unusual Rearrangements of Radical Cations: The Role of Vibronic Coupling
Bally Thomas (2016), Unusual Rearrangements of Radical Cations: The Role of Vibronic Coupling, in Chimia, 70, 164-171.
Variations in Rotational Barriers of Allyl and Benzyl Cations, Anions, and Radicals
Li Zhe, Bally Thomas, Houk Kendall E., Borden Weston T. (2016), Variations in Rotational Barriers of Allyl and Benzyl Cations, Anions, and Radicals, in Journal of Organic Chemistry, 81, 9576-9584.
Electronic Structure of Hole-Conducting States in Polyprolines
Monney Nicolas P.-A., Bally Thomas, Giese Bernd (2015), Electronic Structure of Hole-Conducting States in Polyprolines, in Journal of Physical Chemistry B, 119, 6584-6590.
Electromers of the benzene dimer radical cation
Bloch-Mechkour Anna, Bally Thomas (2015), Electromers of the benzene dimer radical cation, in PCCP, 17, 10624-10629.
Spectroscopic Evidence for Through-Space Arene−Sulfur−Arene Bonding Interaction in m‐Terphenyl Thioether Radical Cations
Monney Nicolas P:-A., Bally Thomas, Yamamoto Takuhei, Glass Richard S. (2015), Spectroscopic Evidence for Through-Space Arene−Sulfur−Arene Bonding Interaction in m‐Terphenyl Thioether Radical Cations, in Journal of Physical Chemistry A, 119, 12990-12998.
One-Pot Synthesis and AFM Imaging of a Triangular Aramide Macrocycle
C. Storz M. Badoux C. M. Hauke T. Solomek T. Bally and A. F. M. Kilbinger (2014), One-Pot Synthesis and AFM Imaging of a Triangular Aramide Macrocycle, in Journal of the American Chemical Society, 136(?), 12832-12825.
Proline as a charge stabilizing amino acid in peptide radical cations
Monney Nicolas P.-A., Bally Thomas, Giese Bernd (2014), Proline as a charge stabilizing amino acid in peptide radical cations, in Journal of Physical Organic Chemistry, 28, 347-353.
The Primary Steps in Excited-State Hydrogen Transfer: The Phototautomerization of o-Nitrobenzyl Derivatives
Tomas Solomek Christian G. Bochet and Thomas Bally* (2014), The Primary Steps in Excited-State Hydrogen Transfer: The Phototautomerization of o-Nitrobenzyl Derivatives, in Chemistry, a European Journal , 20(?), 8062-8067.
Carbocations Generated under Stable Conditions by Ionization of Matrix-Isolated Radicals: The Allyl and Benzyl Cations
Vladimir Misic Krzyzsztof Piech and Thomas Bally (2013), Carbocations Generated under Stable Conditions by Ionization of Matrix-Isolated Radicals: The Allyl and Benzyl Cations, in J. Am. Chem. Soc., 135, 8625-8631.
Spectroscopic Evidence for a New Type of Bonding between a Thioether Radical Cation and a Phenyl Group
Nicolas P.-A. Monney Thomas Bally* Ganga S. Bhagavathy and Richard S. Glass (2013), Spectroscopic Evidence for a New Type of Bonding between a Thioether Radical Cation and a Phenyl Group, in Org. Lett. , 15(19), 4932-4935.
The Bisketene Radical Cation and its Formation by Oxidative Ring-Opening of Cyclobutenedione.
Krzysztof Piech and Thomas Bally (2013), The Bisketene Radical Cation and its Formation by Oxidative Ring-Opening of Cyclobutenedione., in J. Org. Chem. , 78, 2908-2913.
Vibronic Spectra of the p-Benzoquinone Radical Anion and Cation: A Matrix Isolation and Computational Study
Krzysztof Piech Thomas Bally Takatoshi Ichino and John Stanton, Vibronic Spectra of the p-Benzoquinone Radical Anion and Cation: A Matrix Isolation and Computational Study, in Phys. Chem. Chem. Phys.

Collaboration

Group / person Country
Types of collaboration
Prof. Petr Klan, Masaryk University, Brno Czech Republic (Europe)
- Exchange of personnel
Prof. Christian Bochet, Universty of Fribourg Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Dr. Claudio Nunes, University of Coimbra Portugal (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Exchange of personnel
Prof. Thomas Tidwell United States of America (North America)
- Publication
Prof. Richard Glass, University of Arizona at Tuscon United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Prof. John Stanton United States of America (North America)
- Publication

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
Einladung, Universität Belgrad Individual talk Spectroscopic Evidence for a New Type of Bonding between a Thioether Radical Cation and a 18.10.2013 Belgrad, Serbien Monney Nicolas;
Herbstversammlung der Schweizerischen Chemischen Gesellschaft Poster Spectroscopic Evidence for a New Type of Bonding between a Thioether Radical Cation and a Phenyl Group 13.09.2013 EPFL Lausanne, Switzerland Monney Nicolas;
Herbstversammlung der Schweizerischen Chemischen Gesellschaft Poster 1,2-Dialkyl-1,2-Diphenylhydrazine Radical Cations in Low Temperature Solution, and their Rearrangement to p-Benzidine Radical Cations 13.09.2013 EPFL Lausanne, Switzerland Borcea Cristian Iulian;
Herbstversammlung der Schweizeischen Chemischen Gesellschaft Talk given at a conference Photochemistry of o-Nitrobenzyl Photoremovable Protecting Groups 12.09.2013 EPFL Lausanne, Switzerland Bally Thomas;
Summer School in Photochemistry Talk given at a conference Introduction to Photophysics and Photochemistry: What Can Molecules Do After They Have Absorbed Light 25.08.2013 Les Diablerets, Switzerland Bally Thomas;
Radicals in the Rockies Talk given at a conference closed-shell ions in noble gas matrices: a new method and first results 23.07.2013 Telluride, United States of America Bally Thomas;
Radicals in the Rockies Talk given at a conference Photochemistry of o-Nitrobenzyl Photoremovable Protecting Groups 21.07.2013 Telluride, United States of America Bally Thomas; Šolomek Tomáš;
UCLA, Einladung Individual talk The effects of vibronic coupling on the structure, the spectra, and the chemistry of radical cations 18.07.2013 Los Angeles, United States of America Bally Thomas;


Self-organised

Title Date Place
Radicals in the Rockies 21.07.2013 Telluride, United States of America

Knowledge transfer events

Active participation

Title Type of contribution Date Place Persons involved
Summer School in Photochemistry Talk 25.08.2013 Les Diablerets, Switzerland Bally Thomas;


Communication with the public

Communication Title Media Place Year
Talks/events/exhibitions TecDay Collège St. Michel "chimie forensique" (Vortrag & Praktikum für GymnasiastInnen) Western Switzerland 2013

Awards

Title Year
Chorafas-Preis für die beste Dissertation im akademischen Jahr 2013/14 der Naturwissenschaftlichen Fakultät der Universität Fribourg 2014
Paul-Barbara Stipendium der Telluride Academy für die Mitwirkung an einer Konferenz in Telliuride (wird jedes Jahr an einen Doktoranden vergeben) 2013

Associated projects

Number Title Start Funding scheme
132005 Reactive Intermediates: Spectroscopic Investigations, and Quantum Chemical Modelling 01.10.2010 Project funding (Div. I-III)

Abstract

The ability to predict and control the outcome of chemical reactions, be it in biology or technology, frequently requires knowledge of the key reaction intermediates. The present research project focusses on the study of such fleeting species (primarily charged and uncharged radicals as well as closed-shell ions) under conditions where they persist sufficiently long to be probed by conventional spectroscopic means. To this end, suitable precursors are embedded in inert solid media at low temperature where the targeted reactive intermediates may then be generated by photolsis or radiolysis of these precursors. Another approach, mainly for radicals, consists in the pyrolysis of suitable precursors, which has the advantage that the two fragments end up in different matrix cavities and can thus not recombine. The electronic and vibrational spectra of the resulting species contain information that is used to confirm or reject hypotheses with regard to the identity and the structure of reactive intermediates. In addition, their reactivity can be probed by allowing them to rearrange, either by slightly raising the temperature or by exposing them to light at selected wavelengths, or by letting them engage in bimolecular reactions with suitable small reactants with which the host material is doped. A common feature of all projects is, that the experimental work is invariably accompanied by quantum chemical model calculations which serve on the one hand to interpret the spectroscopic observations and on the other hand to shed light on the reactivity of the observed species. Much of the insight obtained in this project arises from a synergy betwen experimental and theoretical approaches.
-