Publications by Thomas Rizzo | EPFL Graph Search

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

We report rotationally resolved spectra of jet-cooled methanol for the OH stretch overtones, 2v(1) and 3v(1), and for the torsional combinations, 2v(1)+v(12), 2v(1)+2v(12), 3v(1)+v(12), and 3v(1)+2v(12). The spectra are obtained by direct excitation from the vibrational ground state with an infrared laser pulse. Population in the resulting upper state levels is detected by infrared laser assisted photofragment spectroscopy (IRLAPS). Global fits of the spectra to the Herbst Hamiltonian yield the torsional an

Lasso peptides form a class of ribosomally synthesized and post-translationally modified peptides (RiPPs) characterized by a mechanically interlocked topology, where the C-terminal tail of the peptide is threaded and trapped within an N-terminal macrolacta ...

Using our recently developed technique of infrared laser assisted photofragment spectroscopy (IRLAPS), we have measured four vibrational overtone bands of jet-cooled CF3H in the N = 4 and N = 5 CH stretch-bend polyads. The cooling in the expansion eliminates much of the rotational congestion and reveals homogeneous structure which reflects the vibrational coupling of the stretch bend states with other modes of the molecule. This homogeneous structure indicates that the coupling of the stretch-bend slates to

We record double resonance spectra of the 4nu(1) band of jet-cooled C-13-methanol using single rotational state selection in the nu(1) fundamental and subsequent promotion of the selected molecules to the fourth vibrational level. We then detect transitions to the final excited states by infrared laser assisted photofragment spectroscopy (IRLAPS). The assigned A symmetry transitions reach upper states with K = 0 and 1, and J from 0 to 5. For E symmetry, the transitions reach levels with Kin the range -3 to

Ion manipulation device for driving ions in a propulsion direction comprising an electrode support for supporting one or more electrodes; a first set of RF electrodes comprising a number n of electrodes, wherein the first set of RF electrodes comprises at least three electrodes; and an RF voltage generator operatively connected to the first set of RF electrodes. The RF voltage generator is configured to generate a plurality of phase-shifted RF voltages, each consecutive phase-shifted RF voltage of the gener

We report UV photodissociation (UVPD) spectra of dibenzo-18-crown-6 (DB18C6) complexes with alkali metal ions (Li+, Na+, K+, Rb+, and Cs+) in a cold, 22-pole ion trap. All the complexes show a number of vibronically resolved bands, but the vibronic structu ...

We have further developed our recently reported two-laser technique for highly selective molecular isotope separation of carbon-13 [Boyarkin, Kowalczyk, and Rizzo, J. Chem. Phys. 118, 93 (2003)] with the objective of increasing the yield. An essential feature of this approach in its original conception is the significant increase of isotopic selectivity that occurs through collisions during the time between the overtone preexcitation laser pulse and the multiphoton dissociation pulse. We demonstrate here th

Coupling vibrational ion spectroscopy with highresolution ion mobility separation offers a promising approach for detailed analysis of biomolecules in the gas phase. Improvements in the ion mobility technology have made it possible to separate isomers with ...

The structural elucidation of metabolite molecules is important in many branches of the life sciences. However, the isomeric and isobaric complexity of metabolites makes their identification extremely challenging, and analytical standards are often require ...

The combination of infrared-optical double resonance excitation with infrared laser assisted photofragment spectroscopy (IRLAPS) detection permits the measurement of rotationally resolved vibrational overtone spectra of jet-cooled CF3H. The IRLAPS detection technique is sufficiently selective to be able to discriminate against the dissociation of molecules in the ground state and the upsilon(CH)=1 level used as an intermediate in the double resonance scheme. The combination of this selective detection techn

Rotationally resolved vibrational overtone spectra of several CH stretch bands of CF3H have been obtained using a combination of jet-cooling, infrared-optical double-resonance, and infrared laser assisted photofragment spectroscopy detection. The high selectivity and sensitivity of this combination allows measurement of spectral splittings that determine the secondary time scales of vibrational energy redistribution. The spectroscopic results show that in the energy region of the v(CH)=3-5 CH stretch levels

We have performed a direct measurement of one of the most fundamental thermochemical values: the O-H bond energy in water. Using a triple-resonance laser excitation scheme, we excite the molecule through a series of vibrational overtone transitions to acce ...

While glycans are present on the surface of cells in all living organisms and play key roles in most biological processes, their isomeric complexity makes their structural characterization challenging. Of particular importance are positional isomers, for w ...

Understanding the relation between the gas-phase structure of biological molecules and their solution-phase structure is important when attempting to use gas-phase techniques to address biologically relevant questions. Directly after electrospray ionizatio ...

: Despite the essential role that glycans play in many biological processes, their isomeric com-plexity makes their structural determination partic-ularly challenging. Tandem mass spectrometry has played a central role in glycan analysis, and recent work h ...

We investigate here the mechanism of collisionally-enhanced isotopic selectivity observed in infrared multiple photon dissociation (IRMPD) of vibrationally pre-excited CF3H by Boyarkin et al. (J. Chem. Phys. 118, 93 (2003)). For both the carbon-12 and carb ...

We report here torsional analysis of rotationally resolved spectra of the 3 nu(1), 5 nu(1), and 6 nu(1) (OH stretch) bands of jet-cooled methanol. The upper states are reached by a double resonance excitation scheme involving the selection of single rotational states in the n1 fundamental band. Detection of the overtone transitions (n nu(1)

While approximately 200 human milk oligosaccharide structures (HMOs) have been completely characterized, the precise isomeric structures of even more HMOs remain ambiguous. To address this analytical challenge, we employ tandem mass spectrometry (i.e., MS/MS) coupled with cryogenic infrared ion spectroscopy (CIRIS) to characterize and identify novel fucosylated HMOs isolated from pooled human milk. In this approach, the precise structure of isomeric precursor molecules purified by liquid chromatography (LC)

Pulsed laser excitation and photofragment detection methods are used to observe the 17(0,17)

Thomas Rizzo

Chat with Graph Search

Torsion-rotation analysis of OH stretch overtone-torsion combination bands in methanol

Structural Insights from Tandem Mass Spectrometry, Ion Mobility-Mass Spectrometry, and Infrared/Ultraviolet Spectroscopy on Sphingonodin I: Lasso vs Branched-Cyclic Topoisomers

Vibrational Overtone Spectra of Jet‐Cooled CF3H by Infrared Laser Assisted Photofragment Spectroscopy

Rotational and torsional analysis of the OH-stretch third overtone in (CH3OH)-C-13

Device and method for ion mobility and charge separation, and for ion filtering

UV Spectroscopic Studies of Cold Alkali Metal Ion–Crown Ether Complexes in the Gas Phase

Collisionally assisted, highly selective laser isotope separation of carbon-13

High-Throughput Multiplexed Infrared Spectroscopy of Ion Mobility-Separated Species Using Hadamard Transform

New Approach for the Identification of Isobaric and Isomeric Metabolites

ROTATIONAL STATE-SELECTED VIBRATIONAL OVERTONE SPECTROSCOPY OF JET-COOLED MOLECULES

Secondary time scales of intramolecular vibrational energy redistribution in CF3H studied by vibrational overtone spectroscopy

A direct measurement of the dissociation energy of water

Spectroscopic probes of cold, gas-phase biomolecular ions: From amino acids to helical peptides

Identification of N-glycan positional isomers by combining IMS and vibrational fingerprinting of structurally determinant CID fragments

Spectroscopic studies of kinetically trapped conformations in the gas phase: the case of triply protonated bradykinin

How General Is Anomeric Retention during Collision-Induced Dissociation of Glycans?

Isotopically selective collisional vibrational energy transfer in CF3H

Intramolecular energy transfer in highly vibrationally excited methanol. III. Rotational and torsional analysis

Characterization of rare trifucosylated human milk oligosaccharides by cryogenic infrared ion spectroscopy (CIRIS)

The dipole moment of HOCl in v(OH)=4