Article
Chemistry, Multidisciplinary
James D. Watson, Leslie D. Field, Graham E. Ball
Summary: In this study, the NMR spectroscopic analysis of group 8 transition metal methane sigma-complexes in 1,1,1,3,3,3-hexafluoropropane was reported. The experimental observations were supported by DFT and ab initio calculations, providing further details on the structures of these metal complexes.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Physical
Santino J. Stropoli, Thien Khuu, Mark A. Boyer, Natalia Karimova, Coire F. Gavin-Hanner, Sayoni Mitra, Anton L. Lachowicz, Nan Yang, R. Benny Gerber, Anne B. McCoy, Mark A. Johnson
Summary: In this study, the vibrational spectra of H2-tagged, cryogenically cooled X- center dot HOCl (X = Cl, Br, and I) ion-molecule complexes were investigated using electronic structure calculations and an anharmonic theoretical treatment. The results showed the presence of additional bands in the band patterns, similar to X- center dot HOD analogs, indicating excitations of nominally IR forbidden overtones and combination bands.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Chengwu Qiu, Yaroslav Odarchenko, Qingwei Meng, Hongyang Dong, Ines Lezcano Gonzalez, Monik Panchal, Paul Olalde-Velasco, Francesco Maccherozzi, Laura Zanetti-Domingues, Marisa L. Martin-Fernandez, Andrew M. Beale
Summary: The redox state of nanoparticles is an important parameter in cobalt-based Fischer-Tropsch synthesis catalysts. In this study, the compositional evolution of individual CoNPs was investigated in situ during CO/syngas treatment using spatially resolved X-ray absorption spectroscopy and X-ray photoemission electron microscopy. It was found that smaller CoNPs remained in the metallic state in the presence of CO, while larger NPs became partially oxidized. In contrast, in the presence of syngas, the oxide content decreased in larger NPs and increased in smaller NPs. Proximate oxygen vacancies were identified as key parameters influencing the redox behavior of CoNPs.
Article
Chemistry, Multidisciplinary
Muhammad Akram, Harrison LaBollita, Dibyendu Dey, Jesse Kapeghian, Onur Erten, Antia S. Botana
Summary: We present a comprehensive theory of magnetic phases in twisted bilayer chromium trihalides, showing that a wide range of noncollinear magnetic phases can be stabilized as a function of twist angle and interactions. Our results provide an interpretation for recent observations of noncollinear magnetic phases in twisted bilayer CrI3 and demonstrate the possibility of engineering further nontrivial magnetic ground states in twisted bilayer chromium trihalides.
Article
Chemistry, Physical
Hiroki Ubukata, Fumitaka Takeiri, Cedric Tassel, Shintaro Kobayashi, Shogo Kawaguchi, Takashi Saito, Takashi Kamiyama, Shunsuke Kobayashi, Genki Kobayashi, Hiroshi Kageyama
Summary: According to the Hume-Rothery rule, anions with a large difference in ionic radii cannot form solid solutions. However, this study demonstrates that Ba2H3X (X = CI, Br, or I) with a special structure can form trihalide solid solutions containing substantial amounts of each halogen. The analysis of synchrotron X-ray diffraction data reveals a significant deviation of the local structure from the average structural model for the solid solutions, which is mainly attributed to the different size variances of X- anions. Furthermore, the study shows that size-flexible H- anions play an important role in the formation of trihalide solid solutions.
CHEMISTRY OF MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Elena S. Osipova, Ekaterina S. Gulyaeva, Nikolay Kireev, Sergey A. Kovalenko, Christian Bijani, Yves Canac, Dmitry A. Valyaev, Oleg A. Filippov, Natalia Belkova, Elena S. Shubina
Summary: Low-temperature IR and NMR studies combined with DFT calculations revealed the mechanistic complexity of reactions between Mn(i) complex fac-[(dppm)Mn(CO)(3)H] and Lewis acids, involving the formation of mer-[(dppm)Mn(CO)(3)HMIDLINE HORIZONTAL ELLIPSISLA] and unusual dearomatization of the Ph3C+ cation upon hydride transfer.
CHEMICAL COMMUNICATIONS
(2022)
Article
Astronomy & Astrophysics
Laura Lenkic, Alberto. D. D. Bolatto, Deanne. B. B. Fisher, Roberto Abraham, Karl Glazebrook, Rodrigo Herrera-Camus, Rebecca. C. C. Levy, Danail Obreschkow, Carolyn. G. G. Volpert
Summary: Using ALMA observations, the line ratios of CO(3-2) and CO(4-3) were characterized in local analogues of main-sequence galaxies at z similar to 1-2. The study found that the CO(4-3)/CO(3-2) line ratio of these galaxies is higher than previous estimates and consistent with their resemblance to main-sequence galaxies at z similar to 1-2. The relation between star formation rate surface density and CO line ratios was investigated, showing deviations from model predictions at lower star formation rate surface densities.
ASTROPHYSICAL JOURNAL
(2023)
Article
Chemistry, Inorganic & Nuclear
Georgi Popov, Goran Bacic, Charlotte Van Dijck, Laura S. Junkers, Alexander Weiss, Miika Mattinen, Anton Vihervaara, Mykhailo Chundak, Pasi Jalkanen, Kenichiro Mizohata, Markku Leskela, Jason D. Masuda, Sean T. Barry, Mikko Ritala, Marianna Kemell
Summary: Atomic layer deposition (ALD) offers excellent film uniformity and conformality for the deposition of mixed-halide perovskite films. However, ALD is only capable of depositing iodine-based halide perovskites and lacks processes for other halides. In this study, six new low temperature ALD processes for PbCl2 and PbBr2 deposition are described, which are crucial steps for depositing mixed-halide perovskites with ALD.
DALTON TRANSACTIONS
(2022)
Article
Chemistry, Inorganic & Nuclear
Hussah Alawisi, Hadi D. Arman, Zachary J. Tonzetich
Summary: This study investigates the activity of cobalt complexes in catalyzing the hydrogenation of alkenes and semi-hydrogenation of alkynes, highlighting the importance of the shuttling between Co(I) and Co(III) states in the reaction mechanism. The generation of small quantities of Co(II) during catalytic turnover is found to be responsible for the observed isomerization in alkyne semi-hydrogenation.
Article
Optics
Xiaoyan Li, Xiangda Deng, Jinquan Hong, Jidong Lin, Jiangquan Lv, Muxin Yu, Xiangfeng Guan, Shaowu Du, Yunlong Yu, Daqin Chen
Summary: CsPbX3 perovskite quantum dots have great application potential in the field of photoelectronics, but their long-term stability is still limited. This study demonstrates the tunable emission wavelength of CsPbX3 quantum dots in a germanate glass matrix, with high photoluminescence quantum yield and exciton binding energies. The influence of thermal treatment temperature on the photoluminescence properties is also investigated, which is of significance for practical applications.
JOURNAL OF LUMINESCENCE
(2024)
Article
Crystallography
Edwin C. C. Constable, Catherine E. E. Housecroft
Summary: Packing motifs in structurally characterized cis-[M(bpy)(2)X-2] coordination compounds were investigated. The compounds can be divided into two classes: non-solvated cis-[M(bpy)(2)X-2] moieties and those with additional lattice molecules. A recurring packing motif involving intermolecular p-stacking of bpy ligands and CHbpy...X contacts was observed, but slippage of stacked bpy units reduced the effectiveness of face-to-face interaction, making CHbpy...X contacts the dominant crystal-packing interaction. The prevalence of dimeric units versus 1D chains in the solid state was described.
Article
Chemistry, Organic
Nyaya Prakash Pradhan, Kavthekar Rupesh Namdev, Aasheesh Srivastava
Summary: We designed bis(urea) functionalized molecular clips 1a-1e for efficient transmembrane co-transport of H+/Cl- ions. The most promising molecule 1a demonstrated a low nanomolar EC50 value (6.96 nM) for co-transporting H+/Cl- ions via a carrier-mediated pathway, and exhibited selective toxicity against cancerous HeLa cells.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Rathiga Senthooran, Owen J. Curnow, Deborah L. Crittenden
Summary: Experimental and computational studies were conducted on a discrete tetrachloride tetrahydrate cluster and a 1D polymer of chloride monohydrate. It was found that the tetrameric and polymeric structures were computationally unstable in the gas phase, highlighting the importance of an encapsulated environment for their isolation. DFT and DFTB calculations assisted in assigning vibrational modes, with solid-state DFTB calculations allowing for successful mode assignment. The results were consistent with discrete chloride hydrates.
Article
Chemistry, Physical
Linke Song, Xizhen Zhang, Yuxuan Fan, Mengqi Lin, Sai Xu, Jinsu Zhang, Yongze Cao, Yichao Wang, Danyang Wu, Baojiu Chen
Summary: In this study, we investigated the application of CsPbX3 (X = Cl/Br, Br, Br/I, I) quantum dots co-doped with various metal ions in a boro-germanate glass matrix as long wavelength pass filters. The results showed that only Cu2+ ions had a significant effect on the photoluminescence intensity and lifetime. Adding a small amount of Cu2+ achieved photoluminescence quenching while maintaining excellent transmittance and optical density. The quenching/enhancement effect differed for different CsPbX3 quantum dots glasses, depending on their anionic composition.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Multidisciplinary
Wenjie He, Xi Zhang, Dan Gong, Ya Nie, Gang Xiang
Summary: In this study, the structures and physical properties of Mn-X (X = F, Cl, Br, I) co-doped GeSe monolayers were investigated using first-principle calculations. The results showed that Mn-Cl and Mn-Br co-doped GeSe monolayers exhibited high stability, while Mn-F and Mn-I co-doped GeSe monolayers were unstable. The stable Mn-Cl and Mn-Br co-doped GeSe monolayers had complex bonding structures and could tune the magnetic and electronic properties, making them indirect band semiconductors with large carrier mobility and asymmetric spin-dependent band structures. Additionally, Mn-Cl and Mn-Br co-doped GeSe monolayers showed weakened in-plane optical absorption and reflection in the visible band. These findings are significant for electronic, spintronic, and optical applications based on Mn-X co-doped GeSe monolayers.
Article
Polymer Science
Gulzar A. Bhat, Marcetta Y. Darensbourg, Donald J. Darensbourg
Summary: The synthesis of poly(propylene carbonate) with 100% C-13-labeled carbonate carbons has been reported, where the nu(CO3) vibration is lowered by 45 cm(-1), allowing for the observation of nu(NO) stretching motions in incorporated dinitrosyl iron complexes.
Article
Chemistry, Multidisciplinary
Tian-Jun Yue, Bai-Hao Ren, Wen-Jian Zhang, Xiao-Bing Lu, Wei-Min Ren, Donald J. Darensbourg
Summary: A synthetic strategy was presented for enhancing the optical properties of CO2-based polycarbonates by modifying the polymer's topological structure, resulting in terpolymers with tunable carbonate linkages and improved optical properties. This approach offers a promising method for developing polymeric materials with enhanced optical properties while maintaining thermal stability.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Gulzar A. Bhat, Ahmed Z. Rashad, Xiaozhou Ji, Manuel Quiroz, Lei Fang, Donald J. Darensbourg
Summary: In this study, TEMPO-appended polymonothiocarbonates were synthesized through ring-opening copolymerization under ambient conditions. Both atactic and isotactic versions of the polymer were prepared, with the isotactic form showing significantly higher conductivity attributed to its well-defined stereochemistry and regulated charge transport pathway compared to the atactic counterpart.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Mani Sengoden, Gulzar A. Bhat, Donald J. Darensbourg
Summary: Polymers obtained from renewable monomers have attracted attention for their ability to address environmental issues and depletion of fossil fuels. In this study, a renewable eugenol-based epoxide was synthesized and its reactions with CO2, COS, and CS2 were examined. It was found that eugenol epoxide preferentially formed cyclic products with CO2 and CS2, while reacting with COS resulted in the regioselective formation of polymonothiocarbonate polymers at room temperature. The molecular structures of the renewable monomers and their cyclic products were determined using single crystal X-ray diffraction studies. Thermal gravimetric analysis and differential scanning calorimetry revealed that the polymonothiocarbonate polymers were stable up to 200 degrees C and had high glass transition temperatures.
Article
Chemistry, Inorganic & Nuclear
Zachary M. Martinez, Tucker M. Folsom, Yicheng Tong, Ashley K. Archambeau, Donald J. Darensbourg, Michael B. Hall, Cynthia B. Powell, Gregory L. Powell
Summary: The mechanism of CO substitution reaction involving diosmium carbonyl sawhorse complex was studied experimentally and theoretically, revealing a dissociative interchange mechanism. Kinetic measurements and stability studies were in agreement with each other, explaining the unexpected combination of kinetics and stability characteristics observed in the reaction.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Fang-Yu Ren, Kaihong Chen, Li-Qi Qiu, Jin-Mei Chen, Donald J. Darensbourg, Liang-Nian He
Summary: A triblock amphiphilic polymer derived from the copolymerization of CO2 and epoxides is able to efficiently catalyze the visible-light-driven reduction of CO2 to CO. The polymer forms spherical micelles in water, where the metal catalyst is sequestered. The amphiphilic polycarbonate micelle rhenium catalyst shows enhanced catalytic activity and selectivity compared to the corresponding molecular rhenium catalyst in organic solvent, while also suppressing the generation of H-2.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Peiran Wei, Gulzar A. Bhat, Ciera E. Cipriani, Hamza Mohammad, Krista Schoonover, Emily B. Pentzer, Donald J. Darensbourg
Summary: This study reports on the facile synthesis and 3D printing of triblock copolymers that can be covalently modified. Thixotropic inks suitable for direct ink write printing were formulated by dissolving the block copolymers in organic solvent and dispersing NaCl particles. Printed structures with surfaces that could be modified and objects with high solvent resistance and selective degradability were achieved.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Polymer Science
Mani Sengoden, Gulzar A. Bhat, Donald J. Darensbourg
Summary: In recent years, chemists worldwide have made significant progress in synthesizing sustainable polymers from natural product-based building blocks. This shift is driven by the environmental impact of non-biodegradable oil-based polymers and the need to utilize renewable feedstocks. This study presents the synthesis of novel terpolymer using a well-defined catalyst system and investigates the mechanistic details of the polymerization reactions. The resulting terpolymers show increased thermal stability with higher proportions of the renewable building block.
Review
Chemistry, Multidisciplinary
Peiran Wei, Gulzar A. Bhat, Donald J. Darensbourg
Summary: This paper presents a concise review of recent progress in processing techniques for aliphatic polycarbonates, including controlled self-assembly, electrospinning, additive manufacturing, and others. The aim is to provide researchers with an enriched toolbox for selecting the most suitable technique for their materials.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Medicinal
Rajesh K. Raju, Saurabh Sivakumar, Xiaoxiao Wang, Zachary W. Ulissi
Summary: Structural characterization of nanoclusters is a major challenge in nanocluster modeling. Machine learning potentials (MLP) and genetic algorithm (GA) can accelerate the search for global minima. Active learning (AL) strategies bypass the need for extensive training data.
JOURNAL OF CHEMICAL INFORMATION AND MODELING
(2023)
Article
Chemistry, Physical
Rajesh Kumar Raju, Paramaconi Rodriguez, Edward N. Brothers
Summary: Recycling CO2 back to fuels is an ideal solution for controlling anthropogenic global CO2 emissions and providing sustainable alternative energy resources. The use of size-selected nanoclusters in catalysis offers unique electronic and catalytic properties, which differ from larger nanoparticles and bulk catalysts. This study investigates the CO2 electroreduction ability of first-row transition metal nanoclusters and identifies potential nanocluster-based electrocatalysts for methane formation. The findings also reveal a linear scaling relationship between the adsorption free energies of various CO2RR adsorbates and the adsorption free energies of CO2*, O*, and C* adsorbates.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Mani Sengoden, Gulzar A. Bhat, Donald J. Darensbourg
Summary: Recent years have seen significant research efforts in the development of metal-free organocatalysts for coupling reactions of CO2 and epoxides. In this study, a series of boron-phosphonium organocatalysts were synthesized and characterized for catalyzing these reactions. The catalysts exhibited high selectivity and were found to be less hygroscopic compared to metal-based catalysts. They successfully facilitated the copolymerization of CO2 and epoxides to form polycarbonates.
Article
Chemistry, Physical
Panagiotis Krokidas, Stelios Karozis, Salvador Moncho, George Giannakopoulos, Edward N. Brothers, Michael E. Kainourgiakis, Ioannis G. Economou, Theodore A. Steriotis
Summary: This study uses machine learning to investigate the effect of pore structure on molecular diffusivity in metal organic frameworks (MOFs), providing new theoretical and methodological insights into molecular sieving.
JOURNAL OF MATERIALS CHEMISTRY A
(2022)
Review
Chemistry, Multidisciplinary
Gulzar A. Bhat, Donald J. Darensbourg
Summary: Sustainability requires the reuse of carbon sources from CO2 emissions, making carbon capture and utilization essential. Coupling of oxiranes (epoxides) with CO2 can generate cyclic carbonates and polymeric materials, providing a potential solution. It is important to use epoxides derived from renewable resources for a sustainable process.
Article
Polymer Science
David K. Tran, Ahmed Z. Rashad, Donald J. Darensbourg, Karen L. Wooley
Summary: The synthetic transformation of d-xylose into a four-membered cyclic ether enables reactions with carbon dioxide to produce linear polycarbonates through either one-step ring-opening copolymerisation (ROCOP) directly or sequential isolation of a preformed six-membered cyclic carbonate followed by ring-opening polymerisation (ROP).
