Review
Chemistry, Multidisciplinary
Ravi Kumar Venkatraman, Andrew J. Orr-Ewing
Summary: Photochemical reactions are increasingly used for chemical and materials synthesis, involving photoexcitation of molecular chromophores dissolved in solvent. The choice of solvent influences the outcomes by modifying the energies and crossings between electronic states of chromophores. Ultrafast laser spectroscopy can resolve the dynamics of photoexcited molecules, with femtosecond to picosecond resolution, revealing the influences of solvents on internal conversion and intersystem crossing in nonradiative relaxation pathways. Different solvents can selectively affect the excited-state dynamics, as illustrated by examples of aromatic compounds and sunscreen molecules. Ultimately, understanding how solvents impact photodynamics can help control the outcomes of photochemical reactions.
ACCOUNTS OF CHEMICAL RESEARCH
(2021)
Review
Chemistry, Multidisciplinary
Kelly J. Gaffney
Summary: Light-driven chemical transformations offer a promising approach for advancing solar energy and catalysis applications, focusing on capturing non-equilibrium trajectories of electronic excited states and studying 3d metal complexes holds great potential. Recent advancements in ultrafast X-ray laser science have enabled detailed insights into electronic excited state dynamics in these complexes.
Article
Chemistry, Organic
Yonghong Liu, Shuangjie Lin, Dandan Zhang, Bingkun Song, Yunhe Jin, Erjun Hao, Lei Shi
Summary: This work presents a photochemical Nozaki-Hiyama-Kishi coupling reaction enabled by bioinspired Hantzsch ester, which serves as both an electron and a proton donor. The method offers a mild and operationally easy approach that shows broad compatibility with various alkenyl triflates and aldehydes.
Article
Chemistry, Physical
Bryan C. Paulus, James K. McCusker
Summary: This study discusses the possibility of using information from quantum coherence to identify active vibrational degrees of freedom along an excited-state reaction coordinate. The research explores whether quantum oscillations observed in kinetic data indicate vibronic nature and coupling to electronic state-to-state evolution. Results from two chemical systems suggest that while coherences can indicate candidate modes for reaction trajectories, the understanding of factors determining the interplay between coherences, dephasing times, and electronic and geometric structure is insufficient to use this as a robust metric for distinguishing active and spectator modes in ultrafast dynamics.
FARADAY DISCUSSIONS
(2022)
Article
Chemistry, Physical
Samylla Boazegevski, Jeferson Ferreira de Deus, Denis Augusto Turchetti, Leni Campus Akcelrud, Samim Sardar, Cosimo D'Andrea, Franco V. A. Camargo, Giulio Cerullo, Giovanni Bressan, Stephen R. Meech, Ismael A. Heisler
Summary: A detailed photophysical study was conducted on a polymer based on a fluorene derivative using ultrafast nonlinear spectroscopy. The study found significant differences in the photophysical behavior of the polymer in solution and as a film, suggesting a near absence of self-collapsed chain conformations in solution. In the film, interchain interactions promote efficient energy transfer, resulting in faster excited state relaxation compared to solution. The time scales of exciton dynamics revealed in this study are useful for designing blends for optoelectronic and electro-optical devices.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Optics
Hanqing Xiong, Naixin Qian, Yupeng Miao, Zhilun Zhao, Chen Chen, Wei Min
Summary: Super-resolution Raman imaging, which offers higher chemical specificity but lower vibrational contrasts than fluorescence imaging, has been a challenge in achieving biocompatible imaging in the optical far-field. Stimulated Raman Excited Fluorescence (SREF) was discovered as an ultrasensitive vibrational spectroscopy that combines Raman scattering's chemical specificity with fluorescence detection's sensitivity. By integrating STED with background-free FM-SREF, high-contrast super-resolution vibrational imaging with STED-FM-SREF was achieved, offering spatial resolution determined by the signal-to-noise ratio.
LIGHT-SCIENCE & APPLICATIONS
(2021)
Article
Chemistry, Multidisciplinary
Tao E. Li, Abraham Nitzan, Joseph E. Subotnik
Summary: For a small fraction of hot CO2 molecules immersed in a liquid-phase CO2 thermal bath, forming collective vibrational strong coupling (VSC) between the C=O asymmetric stretch of CO2 molecules and a cavity mode accelerates hot-molecule relaxation. The acceleration is resonantly dependent on the cavity mode detuning, cooperatively dependent on Rabi splitting, and collectively scales with the number of hot molecules.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Review
Physics, Multidisciplinary
Woojae Kim, Andrew J. Musser
Summary: The multitude of ultrafast photoinduced reactions in organic semiconductors are influenced by the interplay between nuclear and electronic degrees of freedom. Ultrafast time-domain Raman methods have been utilized to study singlet fission and improve solar cell efficiencies.
ADVANCES IN PHYSICS-X
(2021)
Article
Chemistry, Physical
Wenpeng Yuan, Dongyuan Yang, Baihui Feng, Yanjun Min, Zhichao Chen, Shengrui Yu, Guorong Wu, Xueming Yang
Summary: The excited-state decay dynamics of 2-ethylpyrrole following UV excitation in different wavelength ranges were investigated, showing different lifetimes and characteristics for various excited states.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Dexia Zhou, Fang Zhang, Baihui Wang, Jiman He, Yimin Bai, Hongtao Bian
Summary: Anion recognition through noncovalent interactions is an emerging field in supramolecular chemistry. This study investigates the thermodynamics of complexation between sodium cyanate and calix[4]pyrrole, revealing enthalpy changes as the dominant driving force. Further analysis suggests that anion recognition in solution is mediated by conformational changes of the receptor and collective rearrangement of hydrogen bond dynamics.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Multidisciplinary Sciences
Jie Yang, Riccardo Dettori, J. Pedro F. Nunes, Nanna H. List, Elisa Biasin, Martin Centurion, Zhijiang Chen, Amy A. Cordones, Daniel P. Deponte, Tony F. Heinz, Michael E. Kozina, Kathryn Ledbetter, Ming-Fu Lin, Aaron M. Lindenberg, Mianzhen Mo, Anders Nilsson, Xiaozhe Shen, Thomas J. A. Wolf, Davide Donadio, Kelly J. Gaffney, Todd J. Martinez, Xijie Wang
Summary: Water, as one of the most important yet least understood liquids in nature, exhibits anomalous properties due to its well-connected hydrogen bond network. Ultrafast electron scattering technology reveals the rapid structural response and hydrogen bond contraction process of water molecules.
Article
Chemistry, Physical
Pyosang Kim, Andrew J. S. Valentine, Subhangi Roy, Alexis W. Mills, Arnab Chakraborty, Felix N. Castellano, Xiaosong Li, Lin X. Chen
Summary: This study investigated the ultrafast intersystem crossing dynamics of four structurally related platinum(II) dimer complexes and revealed how ligands could fine-tune the potential energy surfaces to influence excited-state trajectories. The results suggest future opportunities in controlling the branching ratio of the dual intersystem crossing pathways through ligand structures.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Chemistry, Multidisciplinary
J. Patrick Zobel, Thomas Knoll, Leticia Gonzalez
Summary: The non-adiabatic dynamics of (VCl3)-Cl-III(ddpd) complex and its phosphorescence properties were studied, revealing that 1-2% of the system can remain stable for 10 picoseconds and exhibit phosphorescence. During the dynamics, nuclear motion mainly involves increasing metal-ligand bond distances and decreasing trans-coordinated ligand atom angles to drive transitions between different electronic states.
Article
Chemistry, Physical
Samantha T. Hung, Sean A. Roget, Weizhong Zheng, Michael D. Fayer
Summary: The dynamics of aqueous magnesium chloride solutions at different concentrations were studied using advanced spectroscopy techniques. The results showed different dynamics for water and Mg2+ ions, indicating a distinct environment for hydrated Mg2+. The hydration number of magnesium was determined to be six, which agreed with other experimental methods. However, deviations were observed near saturation, suggesting changes in Mg2+ solvation due to a shortage of water molecules.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
Article
Chemistry, Physical
Matthew C. C. Rotondaro, Arkash Jain, Shyamsunder Erramilli, Lawrence D. D. Ziegler
Summary: The density dependence of rotational and vibrational energy relaxation of N2O nu(3) asymmetric stretch was measured in dense gas and supercritical Xe and SF6 solutions. The results show that N2O relaxation is more efficient in SF6 compared to Xe due to additional relaxation pathways and electronic factor differences. Near the critical density, N2O relaxation exhibits a critical slowing effect in SF6 but not in Xe due to the coupling of critical density fluctuations to the local N2O environment.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Keun-il Kim, Longteng Tang, Jesse M. Muratli, Chong Fang, Xiulei Ji
Summary: A full cell chemistry of aqueous DIB with graphite cathode and PTCDI anode showed a specific capacity of 41 mAh g(-1) and stable cycling for 400 cycles.
Article
Chemistry, Physical
Sean A. Boulanger, Cheng Chen, Ivan N. Myasnyanko, Mikhail S. Baranov, Chong Fang
Summary: This study investigates the photophysical and photochemical properties of the green fluorescent protein (GFP) chromophore and its derivatives, with a focus on the excited-state intramolecular proton transfer (ESIPT) and its impact on fluorescence properties. Through experimental and computational tools, the researchers uncover the real-time electronic and structural dynamics of two typical ortho-GFP chromophores, o-HBDI and o-LHBDI, which have different bridge-bond constraints. The study reveals a low-frequency phenolic (P)-ring-deformation mode associated with ESIPT and demonstrates the influence of P-ring isomerization on fluorescence enhancement and nonradiative decay pathway. The findings provide crucial insights into solute-solvent interactions and pave the way for the development of versatile fluorescence-based sensors and imaging agents.
JOURNAL OF PHYSICAL CHEMISTRY B
(2022)
Article
Chemistry, Multidisciplinary
Ziyu Wang, Ya Zhang, Cheng Chen, Ruixue Zhu, Jiaming Jiang, Tsu-Chien Weng, Quanjiang Ji, Yifan Huang, Chong Fang, Weimin Liu
Summary: This study utilized femtosecond stimulated Raman spectroscopy and various time-resolved electronic spectroscopies, aided by quantum calculations, to investigate the red fluorescent protein mKeima with a large Stokes shift. It revealed the photocycle and isomerization process of mKeima, and identified the trans-isomer as the dominant contributor to the large Stokes shift emission.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Biochemistry & Molecular Biology
Sullivan Bailey-Darland, Taylor D. Krueger, Chong Fang
Summary: In this work, the excited-state dynamics of a group of nitrophenols with different substituents were systematically studied using spectroscopic techniques and quantum calculations. The location of the substituents was found to have a significant impact on the properties of the compounds, providing important insights for the development of functional molecules for environmental applications.
Article
Biochemistry & Molecular Biology
Taylor D. D. Krueger, Longteng Tang, Cheng Chen, Liangdong Zhu, Isabella L. L. Breen, Rebekka M. M. Wachter, Chong Fang
Summary: Green-to-red photoconvertible fluorescent proteins are important tools for super-resolution imaging. The key residue Ala69 was identified to enhance the green-to-red photoconversion, and Thr69 promoted a stronger pi-pi stacking interaction between the chromophore and His193. These findings can be used to improve other green-to-red photoconvertible proteins for deeper biophysical and molecular biology insights, as well as bioimaging advancements.
Article
Chemistry, Analytical
Taylor D. Krueger, Longteng Tang, Chong Fang
Summary: Fluorescent proteins (FPs) are important tools for noninvasive bioimaging and sensing. REX-GECO1, a red-green emission and excitation ratiometric FP-based biosensor, shows a high dynamic range in measuring cellular calcium concentrations. The potential energy surfaces of these biosensors are revealed using electronic and spectroscopic techniques, uncovering details of their behavior. These findings can inform the design of biosensors with improved efficiency for calcium imaging.
Review
Chemistry, Analytical
Cheng Chen, Chong Fang
Summary: Amine groups are important constituents of organic dyes and have been found to influence the brightness of chromophores. This review focuses on the mechanistic insights of the twisted intramolecular charge transfer (TICT) mechanism and other less common or influential fluorescence quenching mechanisms in amine-containing fluorescent molecules. The review covers various aspects of scientific findings, including the design and synthesis of organic chromophores, theoretical calculations, and spectroscopy techniques, to understand how different amine groups affect the nonradiative decay pathways of excited states.
Article
Biochemistry & Molecular Biology
Janak Solaris, Taylor D. Krueger, Cheng Chen, Chong Fang
Summary: Proton transfer processes are crucial in biological systems. Excited-state intramolecular proton transfer (ESIPT) reactions involve quick and efficient charge transfer and ultrafast proton motions. This study investigates the ESIPT reaction of the fungal pigment Draconin Red using femtosecond transient absorption and excited-state femtosecond stimulated Raman spectroscopy. The results provide insights into the relaxation pathways and excited-state dynamics of the chromophore in solvent. The findings have implications for modeling potential energy surfaces and understanding reaction mechanisms in natural chromophores.
Article
Green & Sustainable Science & Technology
Heng Jiang, Longteng Tang, Yanke Fu, Shitong Wang, Sean K. Sandstrom, Alexis M. Scida, Guoxing Li, David Hoang, Jessica J. Hong, Nan-Chieh Chiu, Kyriakos C. Stylianou, William F. Stickle, Donghai Wang, Ju Li, P. Alex Greaney, Chong Fang, Xiulei Ji
Summary: Rechargeable aqueous zinc batteries are gaining popularity in stationary storage applications due to their safety, cost-effectiveness, scalability, and low carbon footprint. However, the challenge of hydrogen evolution reaction (HER) at the zinc surface hinders the utilization of this reversible redox chemistry. In this study, a concentrated electrolyte design is developed to eliminate HER and achieve high Coulombic efficiency for Zn plating/stripping. The hybrid electrolyte not only enables the formation of a protective solid electrolyte interphase but also enhances battery performance, allowing for sustainable energy storage with high energy density.
NATURE SUSTAINABILITY
(2023)
Review
Chemistry, Multidisciplinary
Taylor D. Krueger, Cheng Chen, Chong Fang
Summary: Red fluorescent proteins (RFPs) are a popular class of genetically encodable bioprobes and biomarkers that can advance breakthroughs in imaging and life sciences. Understanding their working mechanisms requires suitable spectroscopic techniques to delineate key structural features and dynamic steps. Progress has been made in designing RFPs with improved functions and versatility.
CHEMISTRY-AN ASIAN JOURNAL
(2023)
Article
Biochemistry & Molecular Biology
Cheng Chen, J. Nathan Henderson, Dmitry A. Ruchkin, Jacob M. Kirsh, Mikhail S. Baranov, Alexey M. Bogdanov, Jeremy H. Mills, Steven G. Boxer, Chong Fang
Summary: This study systematically analyzed the vibrational properties of FP chromophores by using FSRS and quantum calculations. A bond-stretching mode characteristic of the quinoidal resonance structure was found to be present in most FPs and model chromophores, which can serve as a vibrational marker for interpreting chromophore-environment interactions and structural effects on the electronic properties of the chromophore.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Materials Science, Multidisciplinary
Xueqiao Zhang, Ye Liu, Chieh-Hsi Kuan, Longteng Tang, Taylor D. Krueger, Sanjida Yeasmin, Ahasan Ullah, Chong Fang, Li-Jing Cheng
Summary: Researchers have discovered red carbon dots with large Stokes shifts and demonstrated their potential for display applications by creating multicolor patterns and color-conversion LEDs using printable carbon dot inks.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Article
Chemistry, Physical
Cheng Chen, Hao Zhang, Jing Zhang, Hui-wang Ai, Chong Fang
Summary: The incorporation of ncAAs into fluorescent proteins has the potential to red-shift their fluorescence and improve tissue imaging. However, ncAA-based RFPs are rare. The recent advance of 3-aminotyrosine modified sfGFP has provided insights into the molecular mechanism of red-shifted fluorescence, but its dim fluorescence limits its applications.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
