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Thomas Rizzo

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Publications associées (100)

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Using Hadamard Transform Multiplexed IR Spectroscopy Together with a Segmented Ion Trap for the Identification of Mobility-Selected Isomers

Thomas Rizzo, Ahmed Ben Faleh, Stephan Warnke, Vasyl Yatsyna, Ali H Abikhodr

The high isomeric complexity of glycans makes them particularly difficult to analyze. While ultra-high-resolution ion mobility spectrometry(IMS) can offer rapid baseline separation of many glycan isomers,their unambiguous identification remains a challengi ...

2023

Microsolvation effects on the excited state dynamics of protonated tryptophan

Ursula Röthlisberger, Ivano Tavernelli, Thomas Rizzo, Oleg Boyarkine, Michele Cascella, Matteo Guglielmi, Anthi Kamariotou

To better understand the complex photophysics of the amino acid tryptophan, which is widely used as a probe of protein structure and dynamics, we have measured electronic spectra of protonated, gas-phase tryptophan solvated with a controlled number of wate ...

2006

Infrared spectroscopy of hydrated amino acids in the gas phase: protonated and lithiated valine

Thomas Rizzo, Oleg Boyarkine, Rainer Beck, Anthi Kamariotou

We report here infrared spectra of protonated and lithiated valine with varying degrees of hydration in the gas phase and interpret them with the help of DFT calculations at the B3LYP/6-31++G** level. In both the protonated and lithiated species, our resul ...

2006

Highly-resolved Spectra of Gas-phase Gramicidin S: A Benchmark for Peptide Structure Calculations

Thomas Rizzo, Oleg Boyarkine, Natalia Nagornova

We have measured a vibrationally-resolved UV spectrum of doubly-protonated gramicidin S (GS) in the gas phase and, subsequently, a highly-resolved, conformer-specific infrared spectra in the 6 μm fingerprint region, using a cold ion trap in combination wit ...

American Chemical Society2010

Cryogenic Ion Spectroscopy for Identification of Monosaccharide Anomers

Thomas Rizzo, Valeriu Scutelnic

We combine conformer-selective, cryogenic infrared spectroscopy, quantum mechanical computations, and 18O substitution at the reducing end to determine the structural preferences of protonated glucosamine in the gas phase. Cryogenic infrared-infrared (IR-I ...

2019

State-selective spectroscopy of water up to its first dissociation limit

Thomas Rizzo, Oleg Boyarkine, Pavlo Maksyutenko, Maxim Grechko

A joint experimental and first-principles quantum chemical study of the vibration-rotation states of the water molecule up to its first dissociation limit is presented. Triple-resonance, quantum state selective spectroscopy is used to probe the entire ladd ...

2009

Laser isotope separation method employing isotopically selective collisional relaxation

Thomas Rizzo

A method of separating isotopes from polyatomic molecules, in particular C from trifluoromethane HCF3, by applying to the polyatomic molecules in the gas phase infrared laser beams of different frequencies to produce multiphoton dissociation and reacti ...

2007

Spectroscopy and Conformational Preferences of Gas-Phase Helices

Thomas Rizzo, Oleg Boyarkine, Caroline Seaiby

We describe here a study of the spectroscopy of two peptides that we expect to be helical, Ac-Phe-(Ala)5-Lys-H+ and Ac-Phe-(Ala)10-Lys-H+, and one that we expect to be globular, Ac-Lys(H+)-Phe-(Ala)10, with the goal of identifying spectral features charact ...

2009

Cryogenic Methods for the Spectroscopy of Large, Biomolecular Ions

Thomas Rizzo, Oleg Boyarkine

Determining the conformation of biological molecules is key for understanding their function. The recent combination of mass spectrometry, cryogenic ion traps, and laser spectroscopy is providing new methods to interrogate individual conformations of pepti ...

Springer2015

UV and IR spectroscopy of cold 1,2-dimethoxybenzene complexes with alkali metal ions

Thomas Rizzo, Oleg Boyarkine, Yoshiya Inokuchi

We report UV photodissociation (UVPD) and IR-UV double-resonance spectra of 1,2-dimethoxybenzene (DMB) complexes with alkali metal ions, M+•DMB (M = Li, Na, K, Rb, and Cs), in a cold 22-pole ion trap. The UVPD spectrum of the Li+ complex shows a strong ori ...

2012

State-resolved gas-surface reactivity of methane in the symmetric C-H stretch vibration on Ni(100)

Thomas Rizzo, Rainer Beck, Marco Sacchi, Plinio Maroni, Thanh Tung Dang

The state-resolved reactivity of CH4 in its totally symmetric C-H stretch vibration (nu(1)) has been measured on a Ni(100) surface. Methane molecules were accelerated to kinetic energies of 49 and 63.5 kJ/mol in a molecular beam and vibrationally excited t ...

2005

Using SLIM-Based IMS-IMS Together with Cryogenic Infrared Spectroscopy for Glycan Analysis

Thomas Rizzo, Ahmed Ben Faleh, Stephan Warnke, Priyanka Bansal, Ali H Abikhodr, Vasyl Yatsyna, Natalia Yalovenko

The isomeric heterogeneity of glycans poses a great challenge for their analysis. While combining ion mobility spectrometry (IMS) with tandem mass spectrometry is a powerful means for identifying and characterizing glycans, it has difficulty distinguishing ...

2020

Separation and Identification of Glycan Anomers Using Ultrahigh-Resolution Ion Mobility Spectrometry and Cryogenic Ion Spectroscopy

Thomas Rizzo, Ahmed Ben Faleh, Stephan Warnke, Valeriu Scutelnic

The analysis of carbohydrates, or glycans, is challenging for established structure-sensitive gas-phase methods. The multitude of possible stereo-, regio- and structural isomers make them substantially more complex to ana-lyze than DNA or proteins, and no ...

2019

Microhydration Effects on the Encapsulation of Potassium Ion by Dibenzo-18-Crown-6

Thomas Rizzo, Oleg Boyarkine, Yoshiya Inokuchi

We have measured electronic and conformer-specific vibrational spectra of hydrated dibenzo-18-crown-6 (DB18C6) complexes with potassium ion, K+center dot DB18C6 center dot(H2O)(n) (n = 1-5), in a cold, 22-pole ion trap. We also present for comparison spect ...

American Chemical Society2014

Identification of human milk oligosaccharide positional isomers by combining IMS-CID-IMS and cryogenic IR spectroscopy

Thomas Rizzo, Ahmed Ben Faleh, Stephan Warnke, Vasyl Yatsyna, Ali H Abikhodr

High-resolution ion mobility spectrometry (IMS) coupled with cryogenic infrared spectroscopy has proven to be a powerful technique for the identification of oligosaccharides. However, the need for an extensive database, combined with the scarcity of pure s ...

2023

Kinetically Trapped Liquid-State Conformers of a Sodiated Model Peptide Observed in the Gas Phase

Thomas Rizzo, Chiara Masellis, Markus Schneider

We investigate the peptide AcPheAla(5)Lyar(+), a model system for studying helix formation in the gas phase, in order to fully understand the forces that stabilize the helical structure. In particular, we address the question of whether the local fixation ...

2017

Approaching the full set of energy levels of water

Thomas Rizzo, Oleg Boyarkine, Pavlo Maksyutenko

We report here measurements of rovibrational levels in the electronic ground state of water at the previously inaccessible energies above 26,000 cm-1. The use of laser double-resonance overtone excitation extends this limit to 34,200 cm-1, which correspond ...

2007

Conformational Preferences of Gas-Phase Helices: Experiment and Theory Struggle to Agree: The Seven-Residue Peptide Ac-Phe-(Ala)5-Lys-H+

Thomas Rizzo

The physical chemistry of bio molecules in the gas phase is progressing at a rapid pace. One of the most promising areas is the determination of the conformations of biologically important molecules. Quantitative determination of their relative energies is ...

Wiley-V C H Verlag Gmbh2012

Combining ultra-high resolution ion-mobility spectrometry with cryogenic IR spectroscopy for the study of biomolecular ions

Thomas Rizzo, Ahmed Ben Faleh, Stephan Warnke, Robert Paul Pellegrinelli, Natalia Yalovenko

Double-resonance spectroscopic schemes in combination with cryogenic ion traps are the go-to techniques when isomer-specific high-resolution spectra are required for analysis of molecular ions. Their limitation lies in the requirement for well-resolved, is ...

2019

Fragmentation mechanism of UV-excited peptides in the gas phase

Thomas Rizzo, Oleg Boyarkine, Michael Zachary Kamrath, Aleksandra Zabuga

We present evidence that following near-UV excitation, protonated tyrosine- or phenylalanine–containing peptides undergo intersystem crossing to produce a triplet species. This pathway competes with direct dissociation from the excited electronic state and ...

American Institute of Physics2014