Article
Energy & Fuels
Dehuan Yang, Yun Chen, Yuancheng Wu, Rongtao Yan, Changfu Wei
Summary: A series of phase equilibrium tests were conducted to investigate the impact of various experimental conditions on the phase equilibrium behavior of methane hydrate in different sediment types. The results show that the phase equilibrium condition of pore hydrate is significantly influenced by the experimental conditions and sediment types. A soil hydration characteristic curve (SHCC) is established to describe the relationship among temperature shift, unhydrated water, and dissolved salt. A new phase equilibrium model is introduced to interpret the experimental results, considering osmotic, capillary, and adsorptive effects.
Article
Engineering, Environmental
C. F. Zinola
Summary: An analytical solution of the water mass balance equation considering diffusion and electroosmotic drag fluxes was obtained. The experimental results showed that the operating conditions significantly affected the performance of the fuel cell, and continuous water recycling could preserve the performance stability of the fuel cell.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Chemistry, Physical
Nilda Chasvin, Petr Svenda, Estela Pronsato, Alejandra Diez, Maria Alicia Volpe, Viktor Johanek, Carolina Pistonesi
Summary: The study investigated the adsorption and dissociation of ethanol on Pt/beta-Mo2C for catalytic H-2 production. Results showed that Pt modifies the lattice parameters of beta-Mo2C, affecting the Mo-Mo distances and chemical state of molybdenum and carbon. The presence of Pt increased the catalytic activity of beta-Mo2C for ethanol decomposition, demonstrating a higher production of H-2 at temperatures above 530 K.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Pan Zhao, Zhen-Yi Jiang, Ji-Ming Zheng, Yan-Ming Lin, Aijun Du
Summary: Promoting carrier separation and migration is crucial for improving photocatalytic performance. This work proposes a novel heterostructure that enhances carrier activity and exhibits good photocatalytic performance. The results demonstrate the importance of the stacking configuration and the internal electric field in facilitating carrier separation and migration.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Engineering, Chemical
Moustafa S. Abusaif, Amira M. Hyba, Yousry A. Ammar, Mohamed A. Salem, Doaa M. Elsisi, Ahmed Ragab
Summary: This study synthesized two novel water-soluble quinoxaline-2,3-dione-6-sulfohydrazide derivatives and demonstrated their ability to successfully build a blocking layer and effectively protect metals from corrosion through experimental and theoretical research.
JOURNAL OF THE TAIWAN INSTITUTE OF CHEMICAL ENGINEERS
(2023)
Article
Chemistry, Analytical
Priyanka Chaudhary, Dheeraj Kumar Maurya, Sarita Yadav, Anwesh Pandey, Ravi Kant Tripathi, B. C. Yadav
Summary: This study reports a sustainable, cost-effective, and rapid synthesis method for carbon quantum dots (GCQD) used as a capacitive humidity sensor. Results show that GCQDs synthesized at different carbonization temperatures exhibit different crystallinity and optical properties, with C-2 showing higher sensitivity and shorter response times in sensing tests. Theoretical modeling was performed to investigate the interaction between GCQDs and water molecules, providing insights for the development of efficient humidity sensors.
SENSORS AND ACTUATORS B-CHEMICAL
(2021)
Article
Chemistry, Multidisciplinary
Kevin Artmann, Ru-Jin Li, Selina Juber, Elie Benchimol, Lars Schaefer, Guido H. Clever, Patrick Nuernberger
Summary: This study uses ultrafast spectroscopy to investigate the influence of different guest compounds on the photoswitching characteristics of a supramolecular cage. It is found that the guest can modify the photodynamics of the cage, which may be beneficial for adjusting the applicability of photoswitchable nanocontainers and desired guest compounds.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Environmental Sciences
Jennifer Menzies, Ashley Wilcox, Kenneth Casteel, Kathleen McDonough
Summary: This study evaluated the biodegradability of multiple PEG, PVOH, and CMC polymers. The results showed that all PEGs and PVOHs completely mineralized in the tests, while CMC degradation was influenced by its degree of substitution. In addition, higher inoculum to test chemical ratios resulted in increased rates of biodegradation. Variability was observed in the presence of competent degraders in river water samples, indicating the need for further research to develop a standardized test method.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Chemistry, Multidisciplinary
Nandagopal Bar, Pranesh Chowdhury, Debrupa Biswas, Arindam Ray, Gourab Kanti Das
Summary: The dye-containing Schiff base metal complex is a new member of the photochromic family that has several advantages and potential applications. Through theoretical analysis and experimental verification, the quick responsive characteristics of this system have been understood and utilized for the fabrication of simple devices such as photoprinting, photopatterning, and UV light sensing. The development of this system also opens up possibilities for designing molecular logic gates and keypad locks.
NEW JOURNAL OF CHEMISTRY
(2022)
Article
Materials Science, Ceramics
Rebaz Obaid Kareem, Omer Kaygili, Tankut Ates, Niyazi Bulut, Suleyman Koytepe, Ali Kurucay, Filiz Ercan, Ismail Ercan
Summary: This study revealed the significant impact of Ce content on lattice parameters, bandgap energy, and biocompatibility of Bi-based hydroxyapatites through experimental and theoretical analyses.
CERAMICS INTERNATIONAL
(2022)
Article
Nanoscience & Nanotechnology
Jose J. Perez-Grau, Patricio Ramirez, Vladimir Garcia-Morales, Javier Cervera, Saima Nasir, Mubarak Ali, Wolfgang Ensinger, Salvador Mafe
Summary: This study experimentally and theoretically describes the fluoride-induced negative differential resistance (NDR) phenomena observed in conical nanopores operating in aqueous electrolyte solutions. Different parameters were found to affect the NDR effect, leading to the proposal of a two-region conductance model.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Biochemistry & Molecular Biology
Shaya Y. Al-Raqa, Khaoula Khezami, Esra N. Kaya, Abdulkadir Kocak, Mahmut Durmus
Summary: The study focuses on synthesizing new photosensitizers for cancer treatment using photodynamic therapy technique. One new synthesized photosensitizer showed high singlet oxygen quantum yield in water solution, characterized and studied using comprehensive spectroscopic methods.
JOURNAL OF BIOLOGICAL INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Physical
Asli Sayar, Nurdil Eskin
Summary: This study experimentally and theoretically investigated a natural gas fuel processor, validating its performance criteria under ideal conditions and determining its efficiency growth trend.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Physical
Lala Ibrahimzade, Omer Kaygili, Serkan Dundar, Tankut Ates, Sergey V. Dorozhkin, Niyazi Bulut, Suleyman Koytepe, Filiz Ercan, Canbolat Gurses, Ala Hamd Hssain
Summary: This study provides a comprehensive investigation on the experimental and theoretical characterization of Ce-doped hydroxyapatite samples additionally doped with varying amounts of Pr. The theoretical modeling showed changes in bandgap energy, attenuation coefficient, and lattice parameters. Experimental results confirmed an increase in beta-tricalcium phosphate phase with the addition of Pr, along with a decrease in crystallinity and an impact on cell viability.
JOURNAL OF MOLECULAR STRUCTURE
(2021)
Article
Biochemical Research Methods
Sazia Iftekhar, Madeleine Rauhauser, Benjamin D. Hage, David S. Hage
Summary: Ultrafast affinity extraction (UAE) was used to investigate the conditions required for accurate measurement of equilibrium constants for solute-binding agent interactions. The results were compared to previous studies and binding experiments using drugs and transport proteins. Equations and trends related to solute dissociation and equilibrium free fraction were identified. The findings have important implications for future research on other solutes and binding agents.
JOURNAL OF CHROMATOGRAPHY A
(2023)
Article
Chemistry, Organic
Joshua L. Martin, Girish C. Sati, Tanmay Malakar, Jessica Hatt, Paul M. Zimmerman, John Montgomery
Summary: A novel mode of reactivity involving a dioxolenium ion as a key intermediate that promotes both glycosylation and glycosyl exchange pathways has been discovered through experimental and computational mechanistic studies. By modifying the catalyst structure, it is possible to selectively favor one pathway, leading to improved multicomponent iterative couplings and glycosyl exchange processes.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Duy-Khoi Dang, Leighton W. Wilson, Paul M. Zimmerman
Summary: This article introduces SlaterGPU, a GPU-accelerated library using OpenACC for numerically computing Slater-type orbital (STO) integrals. The electron repulsion integrals (ERI) are computed using the Coulomb potential of the Slater basis function under the RI approximation. By evaluating the Slater integrals in mixed-precision, the ERIs achieve speedups of over 80x, fully exploiting the performance capabilities of modern GPUs. Parallelization on multiple GPUs enables integral throughput of over 3 million integrals per second, making STO integral throughput comparable to single-threaded conventional Gaussian integration schemes. Benchmark tests on the fluorine exchange reaction barrier in fluoromethane and the singlet-triplet gap of cyclobutadiene demonstrate the library's ability to generate the necessary integrals for configuration interaction with up to 6h functions in the auxiliary basis.
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2022)
Article
Chemistry, Physical
Duy-Khoi Dang, Joshua A. Kammeraad, Paul M. Zimmerman
Summary: The heat-bath configuration interaction (HCI) method improves the computational efficiency for approaching the full CI limit. This study introduces computational improvements to the HCI algorithm, targeting speed, parallel efficiency, and memory requirements. The new implementation utilizes a hash function and MPI and OpenMP for parallelism, allowing for the study of a large active space and achieving high parallel efficiency. The accuracy of the new HCI implementation is benchmarked and applied to a challenging complex.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Multidisciplinary
Uvinduni I. Premadasa, Vera Bocharova, Audrey R. Miles, Diana Stamberga, Stella Belony, Vyacheslav S. Bryantsev, Adnan Elgattar, Yi Liao, Joshua T. Damron, Michelle K. Kidder, Benjamin Doughty, Radu Custelcean, Ying-Zhong Ma
Summary: One of the challenges in current DAC technologies is the high energy cost for sorbent regeneration and CO2 release, making large-scale deployment economically unfeasible. In this study, a photochemically-driven approach using a unique photoacid was developed for CO2 release in DAC systems. The results showed that under light irradiation, a significant conversion of total inorganic carbon to CO2 was achieved, confirming the feasibility of energy-efficient CO2 release using light instead of heat.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Medicinal
Eunjae Shim, Ambuj Tewari, Tim Cernak, Paul M. Zimmerman
Summary: Machine learning models are increasingly used to predict the outcomes of organic chemical reactions. These models rely on a large amount of reaction data, which contrasts with the way expert chemists discover new reactions using a small number of relevant transformations. Transfer learning and active learning can address this gap and promote the application of machine learning in real-world challenges of organic synthesis. This Perspective introduces active and transfer learning and explores potential opportunities for further research, particularly in the prospective development of chemical transformations.
JOURNAL OF CHEMICAL INFORMATION AND MODELING
(2023)
Article
Chemistry, Multidisciplinary
James L. Douthwaite, Ruheng Zhao, Eunjae Shim, Babak Mahjour, Paul M. Zimmerman, Tim Cernak
Summary: We developed a new reaction method for the cross-coupling of alkyl amines and aryl carboxylic acids, by preactivating the amine-acid building blocks. This reaction forms C-(sp(3))-C-(sp(2)) bonds and shows good yields for various substrates, including pharmaceutical compounds. High-throughput experimentation led to the discovery of performance-enhancing additives such as phthalimide, RuCl3, and GaCl3.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Roseanne J. Sension, Taylor P. McClain, Ryan M. Lamb, Roberto Alonso-Mori, Frederico Alves Lima, Fernando Ardana-Lamas, Mykola Biednov, Matthieu Chollet, Taewon Chung, Aniruddha Deb, Paul A. Dewan Jr, Leland B. Gee, Joel Huang Ze En, Yifeng Jiang, Dmitry Khakhulin, Jianhao Li, Lindsay B. Michocki, Nicholas A. Miller, Florian Otte, Yohei Uemura, Tim B. van Driel, James E. Penner-Hahn
Summary: Femtosecond time-resolved X-ray absorption, X-ray emission, and broadband UV-vis transient absorption were used to investigate the atomic and electronic dynamics of two vitamin B-12 compounds after photoexcitation. Sequential structural evolution and coherent bond elongation were observed, followed by recoil to a relaxed excited state structure. The formation of a metal-centered excited state with a lifetime of 2-5 ps was suggested by time-resolved X-ray emission and optical transient absorption.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Sophi R. Todtz, Cory W. Schneider, Tanmay Malakar, Clare Anderson, Heather Koska, Paul M. Zimmerman, James J. Devery
Summary: Lewis acid-catalyzed carbonyl-olefin metathesis has revealed new behaviors of Lewis acids, particularly the solution behaviors of FeCl3. Adding TMSCl to FeCl3-catalyzed carbonyl-olefin metathesis leads to significant deviations from normal reactivity, mitigating byproduct inhibition and increasing the reaction rate. Quantum chemical simulations suggest the formation of a silylium catalyst that binds to carbonyl groups, with potential utility in carbonyl-based transformations.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Soumi Tribedi, Duy-Khoi Dang, Bikash Kanungo, Vikram Gavini, Paul M. Zimmerman
Summary: The Ryabinkin-Kohut-Staroverov (RKS) theory connects wave function theory with density functional theory, providing accurate exchange-correlation potentials. In this study, the RKS method is developed and tested with Slater atomic orbital basis functions for the first time. By using full configuration interaction computations with Slater orbital basis, the SlaterRKS approach is shown to efficiently produce exchange-correlation potentials without unphysical artifacts. The enforcement of nuclear cusp conditions is crucial for the success of the Slater-basis RKS method. Examples of weakly and strongly correlated molecular systems demonstrate the main features of SlaterRKS.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Bikash Kanungo, Jeffrey Hatch, Paul M. Zimmerman, Vikram Gavini
Summary: The conventional approaches to the inverse density functional theory problem assume nondegeneracy of the Kohn-Sham eigenvalues, limiting their use in open-shell systems. This study presents a generalized approach that allows for degenerate KS eigenvalues and fractional occupancy of the orbitals, enabling the handling of noninteracting ensemble-v-representable densities. Comparison of exact and model exchange-correlation potentials shows substantial relative errors in the model potentials.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Mo Chen, Austin M. Ventura, Soumik Das, Ammar F. Ibrahim, Paul M. Zimmerman, John Montgomery
Summary: Current methodologies for metal-catalyzed cross-couplings require the installation of reactive functional groups on both reaction partners in advance. In contrast, C-H functionalization approaches show potential in simplifying the substrates required; however, challenges such as low reactivity and similar reactivity of different C-H bonds add complexity. This study describes an oxidative cross dehydrogenative coupling of α-amino C(sp(3))-H bonds and aldehydes to produce ketone derivatives using an unusual reaction medium that simultaneously utilizes di-tert-butyl peroxide as an oxidant and zinc metal as a reductant. The method has a broad substrate scope and offers an attractive approach for accessing α-amino ketones through the formal acylation of C-H bonds adjacent to nitrogen in N-heterocycles. Experimental investigation and computational modeling provide evidence for a mechanistic pathway involving cross-selective nickel-mediated cross-coupling of α-amino radicals and acyl radicals.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Bibek Prajapati, Madan D. Ambhore, Duy-Khoi Dang, Piotr J. Chmielewski, Tadeusz Lis, Carlos J. Gomez-Garcia, Paul M. Zimmerman, Marcin Stepien
Summary: Electronic and steric effects play a crucial role in determining the structure and reactivity of organic compounds. However, tetrafluorenofulvalene (TFF), a twisted alkene, defies conventional rules as its central alkene bond becomes stronger in specific redox states.
Article
Biochemistry & Molecular Biology
Osamah Alghazwat, Adnan Elgattar, Yi Liao
Summary: Carbon dioxide (CO2), the main greenhouse gas causing global warming, can be captured and released repeatedly using a photoacid mixed with a well-studied amine. The photoacid's structural design allows for the tuning of its photoactivity, acidity, and solubility, resulting in efficient CO2 release under moderate visible light irradiation.
PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES
(2023)
Article
Chemistry, Physical
Ya-Nan Yuan, Gao-Jie Yan, Zi-Xuan Wang, Yao-Yao Song, Zhao-Yang Wang, Qing-Lun Wang, Chun Yang, Yi Liao
Summary: This study demonstrates that inclusion complexes of the photoacid MCH1 with cyclodextrins can enhance acidity and chemical stability. The addition of cyclodextrins also slows the thermal relaxation of the photoacid and increases its half-life in aqueous solution.
Article
Chemistry, Physical
Kevin C. Skinner, Josh A. Kammeraad, Troy Wymore, Alison R. H. Narayan, Paul M. Zimmerman
Summary: This study introduces a combined constrained density functional theory and molecular mechanics tool for studying the mechanisms of radical-polar crossover reactions involving organic electron donors. Surprising findings were made, and the importance of considering solvent dynamics in accurately quantifying SET kinetics and thermodynamics was emphasized. This new method proves to be useful for studying reactions in the condensed phase.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
