Article
Chemistry, Multidisciplinary
Stephen A. Miller
Summary: This study investigates the structure, stability, and cooperative bonding of alpha-quartz silica (SiO2) through computational molecular orbital analysis.The results show that despite the geminal oxygen-oxygen distances of 2.61-2.64 angstrom, silica model complexes exhibit anomalously large O-O bond orders that increase with increasing cluster size. The long covalent bond theory (LCBT) proposed in this study suggests that non-canonical O-O bonds play a subtle but crucial role in the structure and stability of Earth's most abundant material.
FRONTIERS IN CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Hanna He, Xiaolong Li, Dan Huang, Jinyi Luan, Sailin Liu, Wei Kong Pang, Dan Sun, Yougen Tang, Wenzheng Zhou, Lirong He, Chuhong Zhang, Haiyan Wang, Zaiping Guo
Summary: Through electron injection engineering, a reorganization of Mo 4d orbitals is triggered, resulting in a 100% phase transition of MoS2 from 2H to 1T. The composite of TiO-1T-MoS2 NFs demonstrates higher electronic conductivity, lower Na+ diffusion barrier, and more restricted S release compared to 2H-MoS2. The stable bonding of conductive TiO successfully improves the stability of the IT phase, leading to excellent rate capability and outstanding cyclability of the TiO-1T-MoS2 NFs electrodes in sodium ion batteries.
Article
Chemistry, Multidisciplinary
Pierre Funk, Ruben B. Richrath, Fabian Bohle, Stefan Grimme, Andreas Gansauer
Summary: A titanocene-catalyzed reaction for synthesizing acetals and hemiaminals from benzylic ethers and benzylic amines, respectively, using pendant epoxides is described. The reaction mechanism involves catalysis in single-electron steps, including oxidative addition, H-atom transfer to generate a benzylic radical, and organometallic oxygen rebound as reductive elimination. Stereoselectivity is controlled by hyperconjugative interactions and steric interactions between the titanocene catalyst and the aryl groups of the substrate, with an interesting aspect being the oxidation of the benzylic center under reducing conditions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Evgeniya A. Trifonova, Isaac F. Leach, Winfried B. de Haas, Remco W. A. Havenith, Moniek Tromp, Johannes E. M. N. Klein
Summary: This study investigates different valence states complexes of gold and focuses on the d-configuration and oxidation state of the metal center. It reveals that the bonding of gold(III) is similar to that of copper(III), and the genuine d(10) configuration is not achieved. The sigma bonds in Au(I) species have an increased electron-sharing nature compared to Ag(I) and Cu(I) due to the low-lying 6s orbital. These findings explain why Au(I) and Au(III) complexes often exhibit similar reactivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Jan Hempelmann, Peter C. Mueller, Christina Ertural, Richard Dronskowski
Summary: Layered phase-change materials in the Ge-Sb-Te system exhibit multicenter bonding, which leads to distinct long-range effects in the solid state and explains the metavalent properties as well as the origin of bond-breaking and phase change behavior.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Tobias Hilche, Tim Krebs, Hendrik Weissbarth, Fabian Lang, Gregor Schnakenburg, Andreas Gansaeuer
Summary: The synthesis of enantiomerically pure titanocenes is currently limited to cases with enantiomerically pure substituents at the cyclopentadienyl ligands and to ansa-titanocenes. Here, a new synthetic method is introduced using enantiomerically pure camphorsulfonate (CSA) ligands to control the absolute and relative configuration of titanocene complexes. The desired enantiomerically and diastereomerically pure complexes can be obtained in just two steps.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Helena Keil, Karsten Sonnenberg, Carsten Mueller, Regine Herbst-Irmer, Helmut Beckers, Sebastian Riedel, Dietmar Stalke
Summary: Several publications have discussed the bonding concepts in polyhalides theoretically, focusing on the symmetrical trichlorine monoanion. However, only asymmetric trichlorine anions have been reported so far, except in matrix-isolation studies. This study analyzes trichlorine monoanions in different compounds and provides insight into their structures through X-ray structures, charge density analyses, and quantum-chemical calculations.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Polymer Science
Samar Al-Saleh, Abdullah Alateeq, Abdulaziz H. Alshaya, Amal S. Al-Qahtani, Huda Tulbah, Mashael Binhasan, Sara Shabib, Imran Farooq, Fahim Vohra, Tariq Abduljabbar
Summary: In this study, an experimental adhesive was formulated and reinforced with titanium dioxide (TiO2) or zirconium oxide (ZrO2) nanoparticles to investigate their impact on various mechanical properties. Characterization of the nanoparticles, analysis of mechanical properties, and examination of the resin-dentin interface showed that reinforcement with TiO2 or ZrO2 led to increased shear-bond strength and affected the hybrid layer and resin tag formation. Further studies on the impact of different filler concentrations are recommended.
Article
Chemistry, Multidisciplinary
Kennedy A. Borchardt-Setter, Lian Yu
Summary: A racemic mixture of chiral molecules can crystallize either as a racemic compound or as a conglomerate of enantiopure crystals. Achiral molecules usually form achiral crystals, but occasionally exhibit chiral structures. The relative energies of chiral and achiral crystals are analyzed, revealing that chiral crystals generally have lower energy when chiral separation occurs on crystallization, while achiral crystals have lower energy when no chiral separation occurs. This analysis suggests that chiral and achiral molecules should be studied together to better understand chirality generation by crystallization.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Chemistry, Multidisciplinary
Olivier C. Gagne
Summary: The study of inorganic nitrides reveals structural and electronic effects similar to those found in oxide compounds, with potentially greater distortion magnitude. Promising functional units have been identified for exploring uncharted chemical spaces of inorganic nitrides, which can contribute to advancements in the development of new materials and sustainable energy sources.
Article
Chemistry, Physical
Neung-Kyung Yu, Jeong-Min Lee, Woo-Hee Kim, Bonggeun Shong
Summary: Ruthenium (Ru) has potential applications in microelectronics, but its susceptibility to oxidative etching poses challenges. This study investigated the mechanisms and conditions for Ru oxidative etching using density functional theory calculations. The findings suggest that etching reactions are more favored on a Ru surface than on RuO2. Experimental results support the computational predictions, providing insights for the development of effective Ru oxidative atomic layer etching techniques.
APPLIED SURFACE SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Guoqin Cao, Chaoyang Chen, Hongjie Xu, Jinjin Ban, Fanfan Liu, Gaihuan Yuan, Honghong Lei, Yujie Su, Junhua Hu
Summary: A mechanism based on oxidation induced bonding reconstruction (OBR) was proposed to optimize phase selection during oxidation of amorphous ZrxSi1-x (0.55 < x < 0.75). The formation of an amorphous bilayer structure and a Si-rich Zr-Si layer synergistically impeded oxygen permeation, leading to enhanced hydro chemical stability.
MATERIALS & DESIGN
(2023)
Article
Chemistry, Multidisciplinary
Yaoguo Wang, Genpei Shi, Kuo Wang, Weiwei Tang, Junbo Gong
Summary: The crystallization of chiral compounds is influenced by the interplay of chiral recognition and molecular self-assembly. In this study, we demonstrate that excessive enantiomer functioning as a native crystallization inhibitor selectively suppresses the crystallization of certain polymorphs of DL-methionine. Our results reveal a unique chiral self-positioning mechanism, where excess enantiomer solutes serve as native growth inhibitors, resulting in selective crystallization of only one polymorph of DL-methionine.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Chemistry, Inorganic & Nuclear
Maximilian Fritz, Serhiy Demeshko, Christian Wuertele, Markus Finger, Sven Schneider
Summary: The synthesis of a linearly N-2 bridged, dichromium complex is described. Experimental and computational data support a three-spin electronic structure model with high-spin Cr-II ions antiferromagnetically coupled to an N-2(2-) bridge due to spin-polarized backbonding. The selectivity of the carbonylation reaction is attributed to a spin transition after binding of the first CO ligand.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2023)
Review
Biochemistry & Molecular Biology
Albert Rimola, Nadia Balucani, Cecilia Ceccarelli, Piero Ugliengo
Summary: Researchers have conducted quantum chemical investigations on the importance of glycine in astrophysical chemistry and the origin of life, summarizing the experimental work on its synthesis and condensation to form peptides.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Chemistry, Multidisciplinary
Dongbao Luo, Xianji Qiao, Richard Dronskowski
Summary: The study predicts the mechanical stability of novel hydrogen-free guanidinates and ortho-nitrido carbonates at normal pressure, suggesting favorable exothermic reactions for potential synthesis. The decay of the novel compounds is deemed unlikely due to large kinetic activation barriers and significant Madelung energies stabilizing the highly charged complex anions. The newly discovered CN48- ion is shown to be more covalent compared to other related compounds.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Inorganic & Nuclear
Zili Ma, Kaixuan Chen, Aleksander Jaworski, Jianhong Chen, Anna Rokicinska, Piotr Kustrowski, Richard Dronskowski, Adam Slabon
Summary: The study investigated the diverse functionalities of mixed-anion inorganic compounds, focusing on quaternary metal oxynitrides as promising candidates for photoelectrochemical water splitting. The research found that multiple electrochemical methods are needed to activate the photocurrent characteristics of this metal oxynitride for photoanode fabrication.
INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Rajib Sahu, Dimitri Bogdanovski, Jan-Ole Achenbach, Jochen M. Schneider, Christina Scheu
Summary: The atomic scale characterization of various defects in a MoAlB phase thin film grown by DC sputtering at a synthesis temperature of 700 degrees C is reported. Aberration-corrected scanning transmission electron microscopy reveals the formation of an intergrown metastable Mo3Al2B4 phase accompanied by thermally stable 90 degrees twist boundaries within the pristine MoAlB matrix. The specific structural nature of these defects, as well as faceted grain boundaries and 3D MoB clusters, is observed.
Article
Crystallography
Damian Mroz, Ruimin Wang, Carsten Paulmann, Ulli Englert, Richard Dronskowski
Summary: In this study, anisotropic displacement parameters (ADPs) of an organopalladium complex were obtained from synchrotron diffraction data and compared with first-principles calculations. The results show that the harmonic approximation underestimates the amplitudes of atomic motion by approximately 20%. By calculating the ADPs at a temperature 20 K higher than the actual diffraction temperature, the systematic underestimation of the harmonic theory can be accounted for. The findings highlight the importance of using high-quality experimental benchmarks and provide insights for the application of quasi-harmonic approximation in larger systems.
Article
Chemistry, Physical
Lena Patterer, Pavel Ondracka, Dimitri Bogdanovski, Leonie Jende, Stephan Pruente, Stanislav Mraz, Soheil Karimi Aghda, Bastian Stelzer, Markus Momma, Jochen M. Schneider
Summary: The bond formation at polycarbonate (PC) | X interfaces (X = Ti, Al, TiAl) was investigated using X-ray photoelectron spectroscopy and density functional theory molecular dynamics simulations. Experimental and theoretical results showed that the PC | Ti interface exhibited higher reactivity and interfacial bond strength compared to the PC | Al and PC | TiAl interfaces, making Ti thin films the preferential choice as adhesion layers for PC.
APPLIED SURFACE SCIENCE
(2022)
Article
Materials Science, Multidisciplinary
Damian M. Holzapfel, Denis Music, Stanislav Mraz, Soheil Karimi Aghda, Martin Etter, Pavel Ondracka, Marcus Hans, Dimitri Bogdanovski, Simon Evertz, Lena Patterer, Paul Schmidt, Alexander Schokel, Anders O. Eriksson, Mirjam Arndt, Daniel Primetzhofer, Jochen M. Schneider
Summary: The influence of ion irradiation-induced changes on the structure and thermal stability of metastable (Ti,Al)N coatings deposited by cathodic arc evaporation is systematically investigated. The increase in ion flux and ion energy results in an expansion of the lattice parameter and enhances the thermal stability of the coatings.
Article
Crystallography
Jing Zhang, Alex J. Corkett, Jan van Leusen, Ulli Englert, Richard Dronskowski
Summary: The structures of two phase-pure cobalt(II) cyanoguanidine bromide coordination compounds were solved using X-ray single-crystal data. Diffuse reflectance spectra and IR analysis revealed optical and vibrational differences between these compounds. The magnetic susceptibility measurements indicated isolated Co2+ centers for compound 1 and potential weak antiferromagnetic exchange interactions for compound 2.
Article
Materials Science, Multidisciplinary
Soheil Karimi Aghda, Damian M. Holzapfel, Denis Music, Yeliz Unutulmazsoy, Stanislav Mraz, Dimitri Bogdanovski, Gonenc Fidanboy, Marcus Hans, Daniel Primetzhofer, Alba San Jose Mendez, Andre Anders, Jochen M. Schneider
Summary: The effects of ion irradiation on the structure, elastic properties, and thermal stability of metastable c-(Ti,Al)N thin films synthesized by high-power pulsed magnetron sputtering (HPPMS) and cathodic arc deposition (CAD) are systematically investigated using experiments and density functional theory (DFT) simulations. The results show that the orientation of the films changes with the ion kinetic energy, with CAD films exhibiting a (111) orientation at higher energies. The presence of Frenkel defects and the ion energy flux play a significant role in determining the elastic modulus of the films. Additionally, the increase in Frenkel pair concentration caused by ion irradiation delays the formation of the wurtzite phase in c-(Ti,Al)N.
Article
Materials Science, Multidisciplinary
Soheil Karimi Aghda, Dimitri Bogdanovski, Lukas Lo, Heng Han Sua, Lena Patterer, Damian M. Holzapfel, Arnaud le Febvrier, Marcus Hans, Daniel Primetzhofer, Jochen M. Schneider
Summary: The effect of N-vacancy concentration on the elastic properties of cubic transition metal nitride thin films is systematically studied by density functional theory calculations. Experimentally validated results show that the elastic behavior of the transition metal nitrides depends on both the N-vacancy concentration and the valence electron concentration of the transition metal.
Article
Materials Science, Ceramics
Matej Fekete, Clio Azina, Pavel Ondracka, Lukas Lofler, Dimitri Bogdanovski, Daniel Primetzhofer, Marcus Hans, Jochen M. Schneider
Summary: Thermal shock resistance is a crucial property for applications that require extreme temperature gradients. The thermal shock parameter RT is used to describe the resistance of a material. In this study, the thermo-mechanical properties of Ti3AlC2 and Cr2AlC MAX phases were predicted and compared using quantum-mechanical calculations and experiments. Coatings of these materials were synthesized using direct current magnetron sputtering and vacuum annealing. The results showed good agreement between the simulated and experimental RT values for both materials. Comparing the MAX phase coatings, it was found that Ti3AlC2 exhibited superior thermal shock behavior compared to Cr2AlC, primarily due to its larger coefficient of thermal expansion. This study highlights the potential of ab initio calculations for predicting the thermal shock behavior of ionically-covalently bonded materials.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2023)
Article
Polymer Science
Dustin N. N. Jordan, Patrick G. G. Strassburg, Dennis Woschko, Luca M. M. Carrella, Laure P. P. Cuignet, Katharina Eickmeier, Richard Dronskowski, Yann Garcia, Eva Rentschler, Christoph Janiak
Summary: Seven new coordination networks with different structures were synthesized and investigated. The interpenetration of the networks is guided by the coordinated and non-coordinated anions. The role of different anions in the formation of the networks was explored.
Article
Chemistry, Multidisciplinary
Rajib Sahu, Dimitri Bogdanovski, Jan-Ole Achenbach, Marcus Hans, Daniel Primetzhofer, Jochen M. Schneider, Christina Scheu
Summary: Various compositional defects coexist in a MoAlB MAB phase thin film grown by high-power pulsed magnetron sputtering at 800 degrees C. These defects are thermodynamically possible and their formation is observed at the atomic scale. The energy barrier for the formation of the metastable Mo3Al2B4 phase is relatively small.
Article
Chemistry, Inorganic & Nuclear
Sebastian Benz, Da Chen, Andreas Moeller, Michael Hofmann, David Schnieders, Richard Dronskowski
Summary: Carbonic acid, a key molecule in biochemistry, geochemistry, and extraterrestrial chemistry, has been studied for its crystal structure which shows strong hydrogen bonding, pi bonding, and influence of crystal field.
Article
Chemistry, Multidisciplinary
Dimitri Bogdanovski, Peter J. Poellmann, Jochen M. Schneider
Summary: This study reveals that the orthorhombic CrAlB MAB phase can be synthesized as a metastable phase with a low energy barrier. The electronic structures of MoAlB and CrAlB are similar, but MoAlB is more electronically stable. Both phases exhibit similar bonding characteristics, with the transition metal-metal bonds being the dominant interaction. It is possible to directly synthesize metastable CrAlB thin films, and the stability can be enhanced by alloying with Mo.
Article
Chemistry, Multidisciplinary
Can Lu, Andreas Drichel, Jianhong Chen, Florian Enders, Anna Rokicinska, Piotr Kustrowski, Richard Dronskowski, Klaus Boldt, Adam Slabon
Summary: This study investigated the performance of core/shell quantum dots paired with semiconductor photocathodes for water reduction, finding that the integration of quantum dots with NiO photocathodes can significantly enhance water reduction efficiency, with both different structure quantum dots showing similar effects in generating photocurrent enhancement. Exploring the carrier kinetics at the interface of these hybrid photocathodes is critical for the development of efficient PEC proton reduction.
