Sunday, June 13

All times in Eastern Daylight Time (GMT-4)

10:00 - 10:05 am | Opening Remarks

10:05 - 10:20 am | Marta Duchi, University of Zürich, Switzerland

2D-Raman-THz spectroscopy implemented with single-shot THz detection

We present a novel Raman-terahertz setup with single-shot THz detection to reduce the acquisition time from many days to a few hours. The combination of finely made echelons, high repetition rate laser, fast scanning and 100 kHz camera allows a significant improvement in signal-to-noise. Liquid bromoform test measurements are reported.

10:20 - 10:35 am | Ravi Kumar Venkatraman, University of Sheffield, UK

Ultrafast Dynamics at the Lipid−Water Interface: DMSO Modulates H‑Bond Lifetimes

Dimethyl sulfoxide (DMSO) is widely used as a cryoprotectant, and its interaction at the water-lipid interface remains contentious. Herein, we report that the addition of DMSO leads to a non-monotonic behavior of the water dynamics at the lipid membrane interface using 2D IR spectroscopy and MD simulations.

10:35 - 10:50 am | Lara Denninger, Goethe University of Frankfurt, Germany

Photochemistry of a Cyclopropenone-Caged Click Reagent

Click reagents caged by a cyclopropenone group release carbon monoxide upon UV excitation. This photochemical activation allows spatiotemporal control of the click labelling strategy. Here, we investigate the photoreaction of PhotoDIBO-OH by UV?-pump IR-probe spectroscopy to resolve the lifetimes of the different reaction paths.

10:50 - 11:05 am | Luiz Schubert, Free University of Berlin, Germany

Protein Conformational and Protonation Dynamics Monitored by Single-Shot IR Spectroscopy

In this study we used quantum cascade laser (QCL) based dual-comb spectroscopy to study protein conformational and protonation dynamics of bacteriorhodopsin. We provide a comparison between a commercially available dual-comb spectrometer and our homebuilt tunable QCL based spectrometer to showcase the possibility of probing non-repetitive protein dynamics.

11:05 - 11:20 am | Hanna Orlikowska, Poznan University of Technology, Poland

Modulation transfer approach: on the way to routine fluorescence-free imaging of biomimetic membranes

The presentation outlines the first steps we took to provide fluorescence-free imaging of biomimetic membrane components. We used an intensity-modulated pump beam to excite the sample and a probe beam to monitor the induced changes. We show that the signal results from the interplay between different contrast mechanisms.

11:20 - 11:30 am | Break

11:30 - 11:45 am | Lukas Whaley-Mayda, University of Chicago, USA

Fluorescence-encoded Infrared vibrational spectroscopy with single-molecule sensitivity

Fluorescence-encoded Infrared (FEIR) vibrational spectroscopy achieves high detection sensitivity by encoding IR absorption onto a fluorescence signal. Here we describe how FEIR can reach single-molecule (SM) sensitivity with conventional far-field optics and introduce FEIR correlation spectroscopy, which leverages SM fluctuations to probe chemical kinetics at equilibrium.

11:45 - 12:00 pm | Xiao You, University of Texas, USA

Short- and long-range crowding effects on water’s hydrogen bond networks

Intracellular water is confined by high concentrations of biomolecules, which gives it unique properties that determine the structure and dynamics of proteins in cells. Here, we study the tetrahedral structure and H-bond dynamics of water in a crowded environment with 2DIR and MD simulation. We demonstrate that crowders impart different short- and long-range orders on water.

12:00 - 12:15 pm | Robert Weakly, University of Washington, USA

Excited State Vibrational Delocalization in Two-Dimensional Vibronic Spectroscopies

Both 2D Vibrational-Electronic (2D VE) and 2D Electronic-Vibrational (2D EV) spectroscopy carry inherent sensitivity to the interaction of electronic and nuclear degrees of freedom. We utilize a vibronic Hamiltonian to explore the delocalization of coupled vibrations in the excited electronic state and report on its distinct manifestations in peak positions, amplitudes, and orientational response.

12:15 - 12:30 pm | Stephanie Sanders, University of Michigan, USA

New Experimental Design for Phase Stable and Phase Accurate Heterodyne-Detected Sum-Frequency Generation

Phase stable and phase accurate heterodyne-detection is an ongoing problem in sum frequency generation (SFG). We implemented a new heterodyne detection scheme to vary the time between the local oscillator and sample SFG signal that improves the phase accuracy of our previous design while maintaining its phase stability and experimental flexibility.

12:30 - 12:45 pm | Kai Gronborg, University of Pittsburgh, USA

Observation of Angular Momentum Transfer and Molecular Orientation in Rotationally Resolved 2D-IR of CO2(g)

Polarization-controlled 2D-IR spectroscopy was used to capture angular momentum and orientational dynamics of gaseous CO2. Spectral diffusion of rotationally resolved 2D-IR peaks captures the rate at which intermolecular angular momentum transfer occurs. Polarization-controlled experiments offer information about molecular orientation of molecules in particular angular momentum states.

12:45 - 1:05 pm | Break

1:05 - 2:20 pm | Expert Lecturer: Carlos Baiz, University of Texas, USA

Liquid-liquid phase separation in lipid membranes, surfactants, or small aqueous organic molecules produces interfacial hydrogen-bonding networks that differ substantially from the bulk. Biological processes often take place at interfaces, and characterizing local dynamics is essential to understanding these processes. Third-order spectroscopies, like 2D IR, are not inherently interface-selective, instead, interfacial specificity is achieved through vibrational probes. Complementary methods such as HD-SFG, have helped provide a detailed atomistic picture of these environments and untangle the intricate relationship between molecular structure and interfacial dynamics. In this workshop, I will discuss fundamental aspects, recent results, and the challenges of studying liquid-liquid interfaces using ultrafast 2D IR and SFG spectroscopy.

2:20 - 2:30 pm | Break

2:30 - 2:45 pm | Kevin Robben, University of Iowa, USA

Least-Squares Model Fitting to Accelerate Data Acquisition and Replace the CLS Method

We present a comprehensive study of least-squares fitting of multidimensional spectra to multi-Kubo lineshape models. Compared to the CLS method, analysis of spectral diffusion with simulated data shows model fitting yields 6X to 50X higher precision on dephasing parameters, which effectively accelerates data acquisition by two orders of magnitude.

2:45 - 3:00 pm | Wei Weng, University of Pennsylvania, USA

Probing Ligand Effects on the Structural Dynamics of Copper Complexes via Ultrafast mid-Infrared Spectroscopies

Polarization-dependent pump probe spectroscopy and two-dimensional infrared (2DIR) spectroscopy are employed to investigate the influence of ligand structure on the orientational relaxation and spectral diffusion dynamics of a series of copper complexes that mimic the active sites of copper-containing enzymes.

3:00 - 3:15 pm | Eric Arsenault, University of California Berkeley, USA

The initial charge separation step and role of exciton-charge transfer mixing in photosystem II

We report the two-dimensional electronic-vibrational spectroscopic study of photosystem II-reaction center. Through this application, the simultaneous resolution along both the visible excitation and infrared detection axis allows for the disentanglement of the complex energy and electron transfer pathways and characterization of the initial charge transfer state.

3:15 - 3:30 pm | Tammy Leong, Tulane University, USA

Unidirectional coherent energy transport via conjugated oligo(p-phenylene) chains

We used relaxation-assisted two-dimensional spectroscopy (RA 2DIR) to interrogate the energy transport within oligo(p-phenylene) chains and discovered a way to funnel high-frequency vibrational quanta rapidly (8.6 km/s) and unidirectionally over large distances. The study opens avenues for developing materials with controllable energy transport properties, and devices photonic or electrical properties.

3:30 - 3:45 pm | Bing Gu, University of California Irvine, USA

Time-resolved spectroscopy for photochemistry in optical cavities

Photochemical reactions can be manipulated by placing molecules into an optical cavity whereby the strong light-matter coupling creates novel hybrid light-matter states. Time-resolved spectroscopy such as pump-probe transient absorption and stimulated Raman signals are demonstrated to monitor in real-time the complex photochemistry of molecules in optical cavities.

3:45 - 4:00 pm | Till Stensitzki, University of Potsdam, Germany

Ultrafast Backbone Protonation in Channelrhodopsin-1

Proton-transfer reactions are an essential part of the mechanism in many proteins. In general, only certain amino-acid sidechains take part in these reactions. Here we present spectroscopic evidence, that a backbone amide-group acts as a transient proton acceptor in the initial photoreaction of Channelrhodopsin-1.

4:00 - 4:15 | Closing Remarks