Coherent Vibrational Dynamics in an Isolated Peptide Captured with Two-Dimensional Infrared Spectroscopy.

Quantum mechanical vibrational coherence transfer processes play important roles in energy relaxation, charge transfer, and reaction dynamics in chemical and biological systems but are difficult to directly measure using traditional condensed-phase nonlinear spectroscopies. Recently, we developed a new experimental capability to obtain two-dimensional infrared (2D IR) spectra of molecular systems in the gas phase that enables the direct measurement of coherence pathways. Herein, we report ultrafast 2D IR spectroscopy of the peptide glutathione (GSH) isolated and cryogenically cooled in the gas phase.

Two-Dimensional Infrared Spectroscopy of Isolated Molecular Ions.

Two-dimensional infrared (2D IR) spectroscopy of mass-selected, cryogenically cooled molecular ions is presented. Nonlinear response pathways, encoded in the time-domain photodissociation action response of weakly bound N messenger tags, were isolated using pulse shaping techniques following excitation with four collinear ultrafast IR pulses. 2D IR spectra of Re(CO)(CHCN) ions capture off-diagonal cross-peak bleach signals between the asymmetric and symmetric carbonyl stretching transitions.

Ultrafast transient vibrational action spectroscopy of cryogenically cooled ions.

Ultrafast transient vibrational action spectra of cryogenically cooled Re(CO)3(CH3CN)3+ ions are presented. Nonlinear spectra were collected in the time domain by monitoring the photodissociation of a weakly bound N2 messenger tag as a function of delay times and phases between a set of three infrared pulses. Frequency-resolved spectra in the carbonyl stretch region show relatively strong bleaching signals that oscillate at the difference frequency between the two observed vibrational features as a function of the pump-probe waiting time.

New advances in the research of clinical treatment and novel anticancer agents in tumor angiogenesis.

In 1971, Folkman proposed that tumors could be limited to very small sizes by blocking angiogenesis. Angiogenesis is the generation of new blood vessels from pre-existing vessels, considered to be one of the important processes in tumor growth and metastasis. Angiogenesis is a complex process regulated by various factors and involves many secreted factors and signaling pathways.

Pancreatic cancer and fibrosis: Targeting metabolic reprogramming and crosstalk of cancer-associated fibroblasts in the tumor microenvironment.

Pancreatic cancer is one of the most dangerous types of cancer today, notable for its low survival rate and fibrosis. Deciphering the cellular composition and intercellular interactions in the tumor microenvironment (TME) is a necessary prerequisite to combat pancreatic cancer with precision. Cancer-associated fibroblasts (CAFs), as major producers of extracellular matrix (ECM), play a key role in tumor progression.

Origins of the diffuse shared proton vibrational signatures in proton-coupled electron transfer model dyad complexes.

Phenol-benzimidazole and phenol-pyridine dyad complexes have served as popular model systems for the study of proton-coupled electron transfer (PCET) kinetics in solution-phase experiments. Interpretation of measured PCET rates in terms of key structural parameters, such as the H-bond donor-acceptor distance, however, remains challenging. Herein, we report vibrational spectra in the electronic ground state for a series of phenol-benzimidazole and phenol-pyridine complexes isolated and cryogenically cooled in an ion trap.

Theoretical calculation of regioselectivity and solvation effects on B-H activation of -carborane guided by directing group.

This study focuses on uncovering the regioselectivity, directing group, ligand, and solvation effect in B-H activation, which was investigated by DFT calculations. The reaction mechanism was investigated in vacuum, and the advantageous reaction pathway and rate-determining step were determined. Furthermore, the solvation effects and the ligand that coordinated with Pd were studied.

Bio-inspired chitosan-heme-vitamin B-derived Fe-Co bimetallic-doped mesoporous carbons for efficiently electro-activating oxygen.

A bio-inspired bimetallic Fe- and Co-doped nitrogen-carbon material (Fe-Co-N-C) was synthesized using chitosan and porphyrin-like heme and vitamin B12 precursors. Anionic heme with Fe-N4 moieties and vitamin B12 with Co-N4 moieties were grafted onto the surface of acidic chitosan polymers through interactions with cationic -NH3+, and these polymers were coated onto nano-sized silica spheres to form the composite precursors. The optimised thermolysis of these composites yielded mesoporous carbons with abundant surface Fe-Nx and Co-Nx sites.