Article
Chemistry, Analytical
Yating Chen, Wei Chen, Yulan Tian, Ping Zhu, Shuge Liu, Liping Du, Chunsheng Wu
Summary: A fluorescent biosensor utilizing metal-organic frameworks (MOFs) functionalized with DNA and Rhodamine B (RhoB) was proposed for the sensitive detection of alcohols. The biosensor demonstrated high sensitivity towards methanol, ethanol, and isopropanol, with detection limits down to 0.05%, 0.005%, and 0.005% respectively. The selectivity and stability of the biosensor were also evaluated, showing great potential for portable alcohol detection devices.
MICROCHEMICAL JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Xinwei Liu, Liguo Wang, Lianjing Zhai, Cailing Wu, Huanjun Xu
Summary: A simple method using H2O2 as an oxidizing agent without any metal catalysts and under relatively mild conditions has been presented for the synthesis of benzanilides and phenols from aniline by oxidative cleavage of beta-O-4 lignin models. This method is essential for the transformation of lignin into aromatic compounds from biomass.
Article
Chemistry, Multidisciplinary
Jayeon Kim, Taesung Jung, Dong-Woo Cho, Chung-Yul Yoo
Summary: This study systematically investigated the selective adsorption of 1-octene/n-octane liquid binary mixture using different types and weights of zeolites. The results showed that 5A and 13X zeolites exhibited promising selective adsorption of 1-octene due to the preferential adsorption on cation sites in the micropore. On the other hand, 3A and 4A zeolites did not show significant preferential adsorption. The experimental analysis presented in this study provides a solid basis for the development of selective adsorbents for liquid-liquid separation.
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
(2022)
Article
Chemistry, Physical
Marie-Louise Saboungi, Oleg Borodin, David L. L. Price, Bela Farago, Miguel A. A. Gonzalez, Shinji Kohara, Lucile Mangin-Thro, Andrew Wildes, Osamu Yamamuro
Summary: A new class of electrolytes, hybridizing aqueous with non-aqueous solvents, has been reported. The structure of an electrolyte composed of a mixture of LiTFSI-water and LiTFSI-dimethyl carbonate was measured using high-energy X-ray diffraction and polarized neutron diffraction. The results were compared with molecular dynamics simulations, which showed good agreement except for the prediction of intense scattering in partially deuterated samples, indicating a partial segregation between the two solvents not observed in experimental measurements.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Xinyi Liu, Shao-Chun Lee, Soenke Seifert, Lilin He, Changwoo Do, Randall E. Winans, Gihan Kwon, Tao Li
Summary: The relation between solvation structures and transport properties of LiTFSI aqueous solutions was investigated using small-angle X-ray scattering, small-angle neutron scattering, X-ray pair distribution function measurements, and molecular dynamics simulations. It was found that solvation structures of TFSI- consist of solvent separated ion pairs and contact ion pairs, as well as cation-anion aggregates. The relaxation time associated with the anion network structure exhibited the same concentration dependence as the viscosity. This study provides insight into the correlation between solvation structures and transport properties of imide-based lithium-ion salt aqueous electrolytes.
CHEMISTRY OF MATERIALS
(2023)
Article
Mechanics
Luhao Liu, Muwei Yao, Ruoyu Dong, Lijuan Qian, Qingfei Fu
Summary: In this research, the temporal instability of a viscoelastic liquid sheet with unrelaxed tensile stresses in an oscillation gaseous flow field was analyzed using the Floquet method. The effects of oscillation amplitude and frequency of the incoming gaseous flow on instability features in different instability regions were systematically studied. The results indicate that unrelaxed tensile stress has a positive stabilizing effect on the liquid sheet, while higher oscillation amplitude promotes sheet breakup. Additionally, the existence of parametric instability regions is influenced by oscillation and elastic parameters.
Article
Chemistry, Organic
Jun Xu, Chao Peng, Bolin Yao, Hua-Jian Xu, Qiang Xie
Summary: This report describes a method for the deoxyfluorination of alcohols using KF as the fluorine source via in situ generation of highly active CF3SO2F. Diverse functionalities, including halogen, nitro, ketone, ester, alkene, and alkyne, are well tolerated. The mild conditions, short reaction time, and wide substrate scope make this method an excellent choice for constructing C-F bonds.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Xinyi Liu, Shao-Chun Lee, Soenke Seifert, Randall E. Winans, Y. Z, Tao Li
Summary: Water-in-salt (WIS) electrolytes have excellent safety and electrochemical performance, but they have high concentrations, relatively low diffusion coefficient, and high viscosity. Acetonitrile/water in salt (AWIS) electrolytes can overcome these disadvantages. Small-angle X-ray scattering and molecular dynamics simulation were used to investigate the relationship between solvation structures and transport properties. It was observed that AWIS exhibited two solvation behaviors: anions dissolved in acetonitrile forming small clusters, and additional water dissolving these clusters. The introduction of acetonitrile weakened the water-solute interaction and enhanced the cation-anion interaction, resulting in a slowed down dynamics at higher concentrations. This work provides a molecular-level understanding of the connection between two-stage solvation structures and transport properties for imide-based lithium salt solutions.
CHEMISTRY OF MATERIALS
(2023)
Article
Multidisciplinary Sciences
Javad Saien, Mansoureh Bahiraei, Farnaz Jafari
Summary: A novel hydrophobic deep eutectic solvent was evaluated for the extraction of phenol from aqueous solutions, showing excellent extraction capability with high solute distribution coefficients and separation factors. Thermodynamic models NRTL and UNIQUAC were employed to reproduce the experimental data, showing satisfactory agreement with low root mean square deviations.
SCIENTIFIC REPORTS
(2023)
Article
Chemistry, Multidisciplinary
Meng-Yao Li, Jiatong Li, Ao Gu, Xiao-Mei Nong, Shuyang Zhai, Zhu-Ying Yue, Chen-Guo Feng, Yingbin Liu, Guo-Qiang Lin
Summary: A convenient method for synthesizing aryl-containing trisubstituted alkenes through direct alkylation of alkenes was successfully achieved under solvent-free and catalyst-free conditions. The absence of solvents was found to be crucial in initiating this sequence. Moreover, this protocol stands out due to its minimal waste production and straightforward operation. The radical capture experiment provided evidence for an ionic reaction mechanism.
Article
Chemistry, Inorganic & Nuclear
Gabriel Hidalgo, Gabriella Barozzino-Consiglio, Koen Robeyns, Michel Devillers, Eric M. Gaigneaux
Summary: When the precatalyst (2,2'-Hbpy)(3)[PW12O40] reacts with H2O2 under catalytic conditions, it forms two oxidized species, an inactive byproduct (2,2'-bpyHO)(3)[PW12O40] and an activator [WO-(O-2)(2)(2,2'-bpy)]. The activator then activates H2O2 to form the active species for catalyzing the epoxidation reaction. H2O2 also serves as a conservative agent, essential for preventing irreversible deactivation of the catalyst.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Jose M. Otero-Mato, Hadrian Montes-Campos, Victor Gomez-Gonzalez, Martin Montoto, Oscar Cabeza, Svyatoslav Kondrat, Luis M. Varela
Summary: This study investigates the microscopic structure and transport properties of ions in mixtures of 1-butyl-3-methylimidazolium and 1-butyl-3-ethylimidazolium iodide with ethanol. The results reveal essential differences in ionic structure compared to the same ionic liquids in water. The conductivities of these systems are calculated and compared with experimental data, showing reasonable agreement. The pseudo-lattice random-alloy model accurately describes the conductivity data, providing a valuable tool for understanding the concentration dependence of ionic liquid-solvent mixtures.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Chemistry, Inorganic & Nuclear
Andres Alguacil, Franco Scalambra, Antonio Romerosa
Summary: In this study, a series of complexes were synthesized and characterized, and their crystal structures, including a previously published complex, were reported. The behavior of two ligands, PTA and dmoPTA, in terms of protonation and coordination, was discussed based on 15N nuclear magnetic resonance data. The construction of a library of 15N chemical shifts shed light on important features regarding the coordination of PTA and its derivatives.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Wangbing Li, Zhichao Lu, Gerald B. Hammond, Bo Xu
Summary: The use of an unbalanced ion pair promoter accelerates nucleophilic fluorinations, and conversion of ion exchange resin to a polymer-supported ion pair promoter allows for reuse in continuous flow conditions with good water tolerance.
Article
Chemistry, Organic
Zhi-Yun Liu, Silas P. Cook
Summary: This study presents a light-driven, copper-mediated trifluoromethylation of O-alkyl thiocarbonates, which exhibits broad functional group tolerance and offers an alternative method for trifluoromethylation. A radical organometallic mechanism is proposed in this work.
Article
Chemistry, Physical
Susi Lehtola, Miguel A. L. Marques
Summary: The homogeneous electron gas (HEG) is a crucial element in constructing exchange-correlation functionals in density-functional theory. By generalizing the local density approximation (LDA) through a geometric averaging of electron and kinetic energy densities, a new family of functionals, meta-local density approximations (meta-LDAs), is introduced. This new ladder of functionals, based on properties of the HEG, offers improved numerical stability and accuracy in exchange energies compared to traditional approximations.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2021)
Article
Chemistry, Physical
Susi Lehtola, Maria Dimitrova, Heike Fliegl, Dage Sundholm
Summary: This study assessed the accuracy of 51 density functional approximations for predicting magnetic properties, with BHandHLYP functional proving to be the most accurate. Some older functionals such as CAM-B3LYP and newer Berkeley and Florida functionals also yielded accurate results, while Minnesota functionals showed unsatisfactory performance. Additionally, a new numerical integration approach for calculating magnetizabilities was introduced in the study.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2021)
Article
Chemistry, Physical
Muhammad F. Kasim, Susi Lehtola, Sam M. Vinko
Summary: Automatic differentiation is a paradigm shift in scientific programming that simplifies calculations and reduces development time. It has fuelled the growth of machine learning techniques and is also proving valuable in quantum chemistry simulations.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Susi Lehtola
Summary: Density fitting or resolution of the identity (DF/RI) is a widely used technique in quantum chemical calculations to speed up various types of calculations. In this work, a stable automated scheme is proposed for forming auxiliary basis sets with the help of a pivoted Cholesky decomposition. The results show promising performance in HF and MP2 calculations with orbital basis sets of at least polarized triple-zeta quality.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2021)
Article
Chemistry, Multidisciplinary
Susi Lehtola, Antti J. Karttunen
Summary: After years of waiting, computational chemistry has finally become more accessible to the masses. This article reviews the availability of free and open source software packages that offer a wide range of functionality, allowing students to perform reasonable modeling on their own devices. The use of FOSS software simplifies the installation and updating process, and also supports comprehensive teaching strategies.
WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE
(2022)
Article
Chemistry, Physical
Vili-Taneli Salo, Rashid Valiev, Susi Lehtola, Theo Kurten
Summary: Recombination of peroxyl radicals is a pathway for the formation of peroxides in the atmosphere, which play a significant role in the formation of submicron aerosol particles. This study investigates the formation and decomposition of tetroxide intermediates, providing mechanistic insights for understanding the process of tetroxide formation. The results suggest that this mechanism can plausibly explain the formation of aerosol-relevant larger peroxides in the atmosphere.
JOURNAL OF PHYSICAL CHEMISTRY A
(2022)
Article
Chemistry, Physical
Sebastian Schwalbe, Kai Trepte, Susi Lehtola
Summary: The study shows that current state-of-the-art density functional approximations exhibit large errors for excited states, with local density approximation (LDA) functionals showing the most systematic accuracy for 2p and 3d excited states. The best performance overall is observed with the global hybrid GGA functional, while the performance of DM21 is inconsistent.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Susi Lehtola, Miguel A. L. Marques
Summary: Density functional theory is widely used in computational studies in chemistry and materials science. However, there is a need to improve the numerical behavior of density functional approximations to ensure accurate and efficient calculations.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Shivesh Pathak, Ignacio Ema Lopez, Alex J. Lee, William P. Bricker, Rafael Lopez Fernandez, Susi Lehtola, Joshua A. Rackers
Summary: The HF theorem allows efficient force calculations for large systems using ML models for the electron density. However, the well-known Pulay force has hindered the general acceptance of the HF approach for atom-centered basis sets due to its significant error. This work demonstrates that by using an augmented Gaussian basis set for density functional calculations, the Pulay force can be suppressed and HF forces can be computed as accurately as analytical forces, enabling reliable geometry optimization and molecular dynamics simulations. These results provide a clear path for accurate and efficient simulation of large systems using ML densities and the HF theorem.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Susi Lehtola
Summary: Density functional calculations on atoms are used to determine accurate initial guesses and generate various types of pseudopotential approximations and efficient atomic-orbital basis sets. This study describes the implementation of the spherical symmetric densities for density functional approximations (DFAs) and discusses the importance of density thresholding. The results show that all the functionals studied in this work yield total energies converged to 0.1 mu Eh when densities smaller than 10-11a0-3 are screened out.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Chemistry, Physical
Giovanni Li Manni, Ignacio Fdez. Galvan, Ali Alavi, Flavia Aleotti, Francesco Aquilante, Jochen Autschbach, Davide Avagliano, Alberto Baiardi, Jie J. Bao, Stefano Battaglia, Letitia Birnoschi, Alejandro Blanco-Gonzalez, Sergey I. Bokarev, Ria Broer, Roberto Cacciari, Paul B. Calio, Rebecca K. Carlson, Rafael Carvalho Couto, Luis Cerdan, Liviu F. Chibotaru, Nicholas F. Chilton, Jonathan Richard Church, Irene Conti, Sonia Coriani, Juliana Cuellar-Zuquin, Razan E. Daoud, Nike Dattani, Piero Decleva, Coen de Graaf, Mickael G. Delcey, Luca De Vico, Werner Dobrautz, Sijia S. Dong, Rulin Feng, Nicolas Ferre, Michael Filatov (Gulak), Laura Gagliardi, Marco Garavelli, Leticia Gonzalez, Yafu Guan, Meiyuan Guo, Matthew R. Hennefarth, Matthew R. Hermes, Chad E. Hoyer, Miquel Huix-Rotllant, Vishal Kumar Jaiswal, Andy Kaiser, Danil S. Kaliakin, Marjan Khamesian, Daniel S. King, Vladislav Kochetov, Marek Krosnicki, Arpit Arun Kumaar, Ernst D. Larsson, Susi Lehtola, Marie-Bernadette Lepetit, Hans Lischka, Pablo Lopez Rios, Marcus Lundberg, Dongxia Ma, Sebastian Mai, Philipp Marquetand, Isabella C. D. Merritt, Francesco Montorsi, Maximilian Morchen, Artur Nenov, Vu Ha Anh Nguyen, Yoshio Nishimoto, Meagan S. Oakley, Massimo Olivucci, Markus Oppel, Daniele Padula, Riddhish Pandharkar, Quan Manh Phung, Felix Plasser, Gerardo Raggi, Elisa Rebolini, Markus Reiher, Ivan Rivalta, Daniel Roca-Sanjuan, Thies Romig, Arta Anushirwan Safari, Aitor Sanchez-Mansilla, Andrew M. Sand, Igor Schapiro, Thais R. Scott, Javier Segarra-Marti, Francesco Segatta, Dumitru-Claudiu Sergentu, Prachi Sharma, Ron Shepard, Yinan Shu, Jakob K. Staab, Tjerk P. Straatsma, Lasse Kragh Sorensen, Bruno Nunes Cabral Tenorio, Donald G. Truhlar, Liviu Ungur, Morgane Vacher, Valera Veryazov, Torben Arne Voss, Oskar Weser, Dihua Wu, Xuchun Yang, David Yarkony, Chen Zhou, J. Patrick Zobel, Roland Lindh
Summary: This article describes the developments of the open-source OpenMolcas chemistry software environment since spring 2020, focusing on the novel functionalities in the stable branch and interfaces with other packages. These developments cover a wide range of topics in computational chemistry and provide an overview of the chemical phenomena and processes that OpenMolcas can address.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Chemistry, Physical
Susi Lehtola
Summary: This study re-examines the determination of the regularized nuclear potential and finds errors in the original tabulations. Using a simple radial quadrature scheme, higher accuracy and normalization condition satisfaction can be achieved. Furthermore, the study shows that the regularized potential can accurately reproduce orbital energies and shapes even with small parameter values and can converge to sub-meV precision in specific cases.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Chemistry, Physical
Susi Lehtola
Summary: This article describes the implementation of atomic electronic structure calculations using numerical radial basis functions within the finite element method. The stability of the calculation method at small r is discussed, as well as the choice of shape functions. The performance of different shape functions is compared, and it is found that first-order Hermite interpolating polynomials perform well even with large numbers of nodes and nonuniform element grids. The implications of Hermite interpolating polynomials on calculations with meta-GGA functionals are also discussed, and issues with Minnesota functionals are identified.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Physical
Susi Lehtola, Miguel A. L. Marques
Summary: Density functional theory is a fundamental method in chemistry and materials science. However, the lack of reliable reference data has resulted in verification problems for novel density functional approximations (DFAs). This work aims to ensure the reproducibility of DFAs and proposes a common framework for verification and testing.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Thomas Bondo Pedersen, Susi Lehtola, Ignacio Fdez Galvan, Roland Lindh
Summary: This review provides an overview of the RI/DF and CD methods in electronic structure calculations, highlighting the close relationship between these two approaches. It traces the evolution and current state of the CD method, which offers not only a numerical procedure for handling ERIs, but also highly accurate approaches for generating auxiliary basis sets for the RI/DF approximation.
WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE
(2023)
