- S. Mohamed, “Integrating Computed Crystal Energy Landscapes in Crystal Form Discovery and Characterisation,” Understanding Intermolecular Interactions in the Solid State: Approaches and Techniques , D. Chopra, eds., Royal Society of Chemistry, 2019, 1 – 31.
- Shirin Behyan, Dimitrios Gritzalis, Rolf Schmidt, Eskedar Kebede, Louis A. Cuccia, Christine DeWolf, “Structural organization and phase behaviour of meta-substituted dioctadecylaminobenzoquinones at the air/water interface,” Phys. Chem. Chem. Phys. 21, 2345-2350 (2019).
- Junghee Seo, Alyssa C. Cabelof, Chun-Hsing Chen, Kenneth G. Caulton, “Selective deoxygenation of nitrate to nitrosyl using trivalent chromium and the Mashima reagent: reductive silylation,” Chem. Sci. 10, 475-479 (2019).
- Bin Wang, Tie-yan Chang, Xiang Gong, Zhao Jiang, Sen Yang, Yu-sheng Chen, Tao Fang, “One-Pot Synthesis of Au/Pd Core/Shell Nanoparticles Supported on Reduced Graphene Oxide with Enhanced Dehydrogenation Performance for Dodecahydro-N-ethylcarbazole,” ACS Sustain. Chem. Eng. 7 (1), 1760-1768 (2019).
NSF’s ChemMatCARS operates three experimental stations in the areas of advanced small-molecule crystallography, liquid surface and interface scattering, and small to wide-angle scattering at the Advanced Photon Source (APS), the premier undulator-based synchrotron source of high-brilliance high-energy x-rays in the U.S.A. The instrumentation at NSF’s ChemMatCARS provides information that addresses a broad range of issues in chemistry and materials research. NSF’s ChemMatCARS is supported by the Divisions of Chemistry (CHE) and Materials Research (DMR), National Science Foundation, under grant number NSF/CHE- 1834750.
Liquid Interfaces Workshop was held on November 21-22, 2019.
At this workshop, attendees contributed to planning for new initiatives at NSF’s ChemMatCARS in X-ray scattering from liquid interfaces, including liquid-solid, liquid-liquid and liquid-vapor interfaces.
NSF’s ChemMatCARS Receives $14 Million Grant from the National Science Foundation
Mark Schlossman of the Department of Physics at the University of Illinois at Chicago [https://schloss.people.uic.edu] and Matthew Tirrell, Ka Yee C. Lee, Yu-Sheng Chen, and Binhua Lin at University of Chicago received a five-year grant for $14.1 million to build a canted undulator beamline at Sector 15, APS under grant number 1836674, to develop new capabilities at NSF’s ChemMatCARS (click here for detailed story).
NSF’s ChemMatCARS Team, March 2019. Left to Right: Natalie Chen, SuYin Grass Wang, Wei Bu, Yu-Sheng Chen, Theodore Betley, Mati Meron, Jason Benedict, Matthew Tirrell, Mark Schlossman, Mrinal Bera, Ka Yee Lee, Binhua Lin
IME Researchers Receive $12 Million Grant for NSF’s ChemMatCARS from the National Science Foundation
Matthew Tirrell, dean of the Institute of Molecular Engineering at the University of Chicago, Mark Schlossman of the University of Illinois at Chicago, Ka Yee C. Lee of the University of Chicago, Theodore Betley of Harvard University, and Jason Benedict of the University at Buffalo, SUNY received a five-year grant for $12 million to operate and develop the National Science Foundation’s (NSF) ChemMatCARS (click here for detailed story).
NSF’s ChemMatCARS Team, May 2018. Front: Yu-Sheng Chen, Mark Schlossman, Binhua Lin, SuYin Grass Wang, Kimberly Simms, Ka Yee Lee. Back: Tieyan Chang, Mati Meron, Mrinal Bera, Jason Benedict, Wei Bu, Theodore Betley, Matthew Tirrell
Characterization of a Reactive Rh2 Nitrenoid by Crystalline Matrix Isolation
Abstract: The fleeting lifetimes of reactive intermediates in C–H functionalization chemistry often prevent their direct characterization. For example, the critical nitrenoid intermediates that mediate Rh2-catalyzed C–H amination have eluded characterization for more than 40 years. In the absence of structural characterization of these species, methodological development is often computationally guided. Here we report the first X-ray crystal structure of a reactive Rh2 nitrenoid, enabled by N2 elimination from an organic azide ligand within a single-crystal matrix. The resulting high-resolution structure displays metrical parameters consistent with a triplet nitrene complex of Rh2. The demonstration of facile access to reactive metal nitrenoids within a crystalline matrix provides a platform for structural characterization of the transient species at the heart of C–H functionalization.
Anuvab Das, Yu-Sheng Chen, Joseph H. Reibenspies, David C. Powers. Characterization of a Reactive Rh2 Nitrenoid by Crystalline Matrix Isolation. J. Am. Chem. Soc., 141 (41), 16232-16236 (2019). doi: 10.1021/jacs.9b09064
Stability of Ligands on Nanoparticles Regulating the Integrity of Biological Membranes at the Nano–Lipid Interface
Abstract: When nanoparticles interact with cellular or organelle membranes, the coating ligands are known to affect the integrity of the membranes, which regulate cell death and inflammation. However, the molecular mechanisms of this modulation remain unresolved. Here, we use synchrotron X-ray liquid surface scattering and molecular dynamics simulations to study interface structures between phospholipids and gold nanorods (AuNRs) coated by surfactant and polyelectrolyte. These ligands are two types of widely used surface modification with different self-assembled structures and stabilities on the surface of nanoparticles. We reveal distinct mechanisms of the ligand stability in disrupting membrane integrity. We find that the cationic surfactant ligand cetyltrimethylammonium bromide detaches from the AuNRs and inserts into phospholipids, resulting in reduced membrane thickness by compressing the phospholipids to align with the shorter ligand. Conversely, the cationic polyelectrolyte ligand poly(diallyldimethylammonium chloride) is more stable on AuNRs; although it adsorbs onto the membrane, it does not cause much impairment. The distinct coating ligand interactions with phospholipids are further verified by cellular responses including impaired lysosomal membranes and triggered inflammatory effects in macrophages. Together, the quantitative analysis of interface structures elucidates key bio–nano interactions and highlights the importance of surface ligand stability for safety and rational design of nanoparticles.
Liming Wang, Peiyu Quan, Serena H. Chen, Wei Bu, Yu-Feng Li, Xiaochun Wu, Junguang Wu, Leili Zhang, Yuliang Zhao, Xiaoming Jiang, Binhua Lin, Ruhong Zhou, Chunying Chen. Stability of Ligands on Nanoparticles Regulating the Integrity of Biological Membranes at the Nano–Lipid Interface. ACS Nano, 13(8), 8680-8693 (2019). doi: 10.1021/acsnano.9b00114
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NSF’s ChemMatCARS is pleased to welcome new postdoc Pan Sun.
On July 8, 2019, NSF’s beamline scientists Mati Meron and Wei Bu hosted a group of REU students from Ohio State, University of Chicago and University of IL Urbana-Champaign.
On June 25-26, 2019, NSF’s ChemMatCARS beamline scientist Wei Bu introduced the synchrotron facility at sector 15 to the students from the 2019 Neutron X-ray School.
NSF’s ChemMatCARS is pleased to welcome summer intern Abhishek Ravada from MaMaSELF Program, Université De Rennes 1, France. He will be working with Dr. Yu-Sheng Chen.
On April 11, 2019, ANL hosted the annual Science Careers in Search of Women Conference (SCSW) and CARS was part of the tour. High-school girls from across the Chicago area came to explore careers in science, technology, engineering and math., Dr. Mrinal Bera of NSF’s ChemMatCARS introduced the synchrotron research at Sector 15.