Article
Chemistry, Physical
T. V. Pavlova, V. M. Shevlyuga, B. V. Andryushechkin, K. N. Eltsov
Summary: This study reports the removal of individual halogen atoms from Si(100)-2x1-Cl and -Br surfaces in STM. The charge states of DBs formed on the Si surface can be manipulated, allowing for tuning the reactivity of the Cl- and Br-terminated surfaces.
APPLIED SURFACE SCIENCE
(2022)
Review
Chemistry, Multidisciplinary
Benjamin D. Bergstrom, Leslie A. Nickerson, Jared T. Shaw, Lucas W. Souza
Summary: Donor/donor and donor carbenes, although relatively new in carbene chemistry, have shown exquisite chemo- and stereo-selectivity in various insertion reactions. Recent studies have demonstrated high levels of diastereo- and enantioselectivity with different transition metal catalysts. Methods involving diazo-based carbene precursors and diazo-free metal carbenes have both been successful, providing context for future developments in this emerging field.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Stefan F. Clewing, J. Philipp Wagner
Summary: Ground state singlet carbenes typically have sigma(2)pi(0) orbital occupations and exhibit concerted sigma-bond insertion and cycloaddition reactions. However, when the electron configuration switches to sigma(0)pi(2), the reaction pathway changes and becomes significantly easier, with negligible or no barriers in a sigma-fashion.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Nanoscience & Nanotechnology
Chenxi Li, Eliezer F. Oliveira, Abhijit Biswas, Anand B. Puthirath, Xiang Zhang, Atin Pramanik, Elias J. Garratt, Mahesh R. Neupane, Bradford B. Pate, Anthony Glen Birdwell, Tony G. Ivanov, Tanguy Terlier, Robert Vajtai, Pulickel M. Ajayan
Summary: Diamond surface functionalization has attracted significant research interest, particularly H-termination due to its ability to enhance surface conductivity. This study focused on exploring the attachment of different functional groups, such as nitrogen and sulfur heteroatoms, on the diamond surface and their impact on electronic structure. The functionalized diamond surfaces were found to possess higher conductivity than H-terminated diamonds and showed a downshift in the conduction band minimum and valence band maximum, indicating a reduced bandgap. These findings suggest the potential of heteroatom functionalizations on diamond surfaces for various electronic applications.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Physical
Lukas Meier, Wolf Gero Schmidt
Summary: The adsorption of cyclic (alkyl) (amino) carbenes on the Si(001) surface was studied using density-functional theory. Two adsorption mechanisms, carbene insertion in Si-H bonds and binding to a surface defect, were investigated. The stability of these configurations depended on the hydrogen chemical potential and the molecular side groups. Molecular diffusion was also influenced by the side groups. Adsorption configurations resulted in electronic states within the silicon band gap and a reduction in the work function.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Materials Science, Coatings & Films
Jan-Willem J. Clerix, Golnaz Dianat, Annelies Delabie, Gregory N. Parsons
Summary: This study investigates the adsorption of DMATMS on SiO2 and the subsequent reactions during TiCl4/H2O ALD. It is found that DMATMS selectively reacts with -OH groups on SiO2 and inhibits the reaction with TiCl4. Additionally, DMATMS can also react with residual -OH groups and reduce nucleation. The effectiveness of DMATMS passivation on SiO2 and H-terminated Si is quantified using Rutherford backscattering spectrometry.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2023)
Article
Chemistry, Physical
Lukas Meier, Wolf Gero Schmidt
Summary: The adsorption behavior of cyclic (alkyl) (amino) carbenes on the monohydride Si(001) surface is investigated using density functional theory. Two different adsorption mechanisms, carbene insertion in Si-H bonds and binding to a surface defect with missing hydrogen, are studied. The stability of these configurations depends on the hydrogen chemical potential and the molecular side groups. The molecular diffusion is also influenced by the side groups. Some adsorption configurations result in electronic states within the silicon bulk band gap. The work function is significantly reduced upon molecular adsorption.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Quantum Science & Technology
Tanvi P. Gujarati, Mario Motta, Triet Nguyen Friedhoff, Julia E. Rice, Nam Nguyen, Panagiotis Kl. Barkoutsos, Richard J. Thompson, Tyler Smith, Marna Kagele, Mark Brei, Barbara A. Jones, Kristen Williams
Summary: Modeling electronic systems is an important application for quantum computers. In this work, the authors propose a workflow to model chemical reactions on surfaces using quantum computing algorithms. They develop and compare two local embedding methods to determine active spaces and introduce a technique for circuit simplification to reduce the quantum resources required.
NPJ QUANTUM INFORMATION
(2023)
Article
Energy & Fuels
Jose Coutinho, Diana Gomes, Vitor J. B. Torres, Tarek O. Abdul Fattah, Vladimir P. Markevich, Anthony R. Peaker
Summary: This article presents a theoretical model of hydrogen-related reactions with impurities in n- and p-type solar-grade silicon. It addresses reactions with dopants and carbon that are relevant to the degradation of silicon solar cells, particularly in light- and elevated temperature-induced degradation. The article highlights the comparative study of hydrogen molecule dissociation in B- and Ga-doped material, the subsequent formation of acceptor-hydrogen pairs, the proposed mechanisms explaining the kinetics of photo-/carrier-induced dissociation of PH and CH pairs in n-type Si, the analysis of reactions involving interactions between molecules with P and C, and the identification of electron and hole traps using atomistic- and wavefunction-resolved models. The thermodynamics of several reactions involving hydrogen with group-III acceptors in silicon is also investigated. Overall, the results provide a first-principles-level understanding of thermally and carrier-activated processes relevant to degradation of Si-based solar cells.
Article
Nanoscience & Nanotechnology
Gabriela Moreira Lana, Xuan Zhang, Christian Mueller, Rene Hensel, Eduard Arzt
Summary: The study investigated the superior adhesion of film-terminated fibrillar microstructures in contact with surfaces of skin-like roughness, showing potential applications in wearable electronics and wound dressing.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Physical
K. N. Brinda, Zhoveta Yhobu, Jan Grzegorz Malecki, Rangappa S. Keri, R. Geetha Balakrishna, D. H. Nagaraju, Srinivasa Budagumpi
Summary: An organized strategy is revealed to control steric and electronic parameters of N-heterocyclic carbene (NHC) Ag (5-10), Au (11/12), and Ni (13/14) complexes as molecular electrocatalysts for the hydrogen evolution reaction (HER) from water. The films of complexes 10, 13, and 14 exhibited improved activity with low overpotential and high current density. The durability test showed a lower decay rate for complexes 10 and 14 after 200 cycles.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Chemistry, Physical
Deb Kumar Bhowmick, Adrian Joe Urban, Manfred Bartsch, Bjoern Braunschweig, Helmut Zacharias
Summary: Efficient control of interface chemistry enables better tunability of electronic properties, and a novel near-UV-initiated direct modification method has been demonstrated to form stable organic monolayers on silicon surfaces with high hydrolytic stability.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Review
Chemistry, Multidisciplinary
Sripati Jana, Yujing Guo, Rene M. Koenigs
Summary: Sigmatropic rearrangements, known for over a century, have recently been increasingly utilized in organic synthesis through carbene transfer reactions. These processes involve sigma-bond cleavage, formation of a new bond between pi-bond and negatively charged atom, and redistribution of pi-electrons. Recent advances in this research area have led to the development of metal-catalyzed enantioselective sigmatropic rearrangements, metal-free photochemical rearrangements, and novel reaction pathways utilizing ylide intermediates.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Yuzhong Wang, Phuong M. Tran, Yaoming Xie, Pingrong Wei, John N. Glushka, Henry F. Schaefer, Gregory H. Robinson
Summary: The study investigated reactions between Lewis bases and an imidazole-based dithione dimer, revealing that both cyclic(alkyl)(amino)carbene and N-heterocyclic carbene can cleave the sulfur-sulfur bonds in the dimer, producing carbene-stabilized dithiolene zwitterions and a spirocyclic silicon-dithiolene compound. The bonding nature of the products was examined using experimental and theoretical methods.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Tahereh Mohammadi Hafshejani, Jonas Wohlgemuth, Peter Thissen
Summary: Strain affects the surface reactivity of H-Si(111) by weakening Si-H bonds and causing intensity fluctuations in bending modes, leading to the formation of a new peak associated with the diffusion of hydrogen atoms. The findings suggest that both back bonds and up bonds are easily oxidized under strain, with the direct formation of Si-OH without an energy barrier. Different oxidation pathways predominate when strain is present.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Physical
Weize Yuan, Harikrishnan Vijayamohanan, Shao-Xiong Lennon Luo, Keith Husted, Jeremiah A. Johnson, Timothy M. Swager
Summary: In this study, oil-in-water colloidal particles of conducting polymer were fabricated via in situ interfacial polymerization. These particles exhibited a unique core-shell structure and could change their shapes and configurations by altering the charge state of the polymer at the interface. The expansion mechanism of the particles relied on the repulsion caused by the positively charged polymer and the insertion of reduced negatively charged oxidant species. The particles could expand up to 400% of their initial dimensions and retain their structure, and could also shrink back to their original size.
CHEMISTRY OF MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Christopher M. Brown, David J. Lundberg, Jessica R. Lamb, Ilia Kevlishvili, Denise Kleinschmidt, Yasmeen S. Alfaraj, Heather J. Kulik, Maria Francesca Ottaviani, Nathan J. Oldenhuis, Jeremiah A. Johnson
Summary: This study introduces a modular heterogeneous catalysis platform that immobilizes catalysts onto supports to improve recyclability and efficiency. The approach utilizes self-assembled metal-organic cages/polyhedra to create well-defined catalyst-functionalized junctions, resulting in nanoconfined catalyst domains.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Multidisciplinary Sciences
Tian Xie, Arthur France-Lanord, Yanming Wang, Jeffrey Lopez, Michael A. Stolberg, Megan Hill, Graham Michael Leverick, Rafael Gomez-Bombarelli, Jeremiah A. Johnson, Yang Shao-Horn, Jeffrey C. Grossman
Summary: This paper presents a method to accelerate the screening of polymer electrolytes using a multi-task graph neural network. It achieves accurate predictions of multiple properties and explores a larger space while providing an open dataset.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Teruhiko Saito, Megan R. Hill, Shao-Xiong Lennon Luo, Hong-Zhou Ye, Troy Van Voorhis, Jeremiah A. Johnson
Summary: A catalytic method for converting common unsaturated polymers into poly(acetylene)-based multiblock copolymers suitable for electronics applications is presented. This method can also be applied to the conversion of polyethylene into PA-containing multiblock materials.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Runze Liu, Zehao Sun, Hejin Huang, Jeremiah A. Johnson, Alfredo Alexander-Katz, Caroline A. Ross
Summary: Diblock Janus-type A-branch-B bottlebrush copolymers (di-JBBCPs) consist of a backbone with alternating A and B side chains, allowing for microphase separation perpendicular to the backbone. The self-assembly of di-JBBCPs was theoretically investigated using a reparametrized dissipative particle dynamics (DPD) model, and the results were compared with experimental data. The model showed good correspondence with the experimentally observed cylinder, gyroid, and lamellar morphologies, and predicted additional spherical phases, indicating the diversity of morphologies achievable with complex BCP molecular architectures.
Article
Chemistry, Multidisciplinary
Keith E. L. Husted, Abraham Herzog-Arbeitman, Denise Kleinschmidt, Wenxu Zhang, Zehao Sun, Alyssa J. Fielitz, An N. Le, Mingjiang Zhong, Jeremiah A. Johnson
Summary: Graft copolymers provide a versatile platform for designing self-assembling materials, but controlling their thermomechanical and morphological properties has been challenging. In this study, a strategy for controlling these properties by varying pendant groups was discovered. This strategy allows for the design of a wide range of materials with different properties. The study also simplifies graft copolymer synthesis and provides access to a diverse family of silicone-based materials.
ACS CENTRAL SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Gabriel Bradford, Jeffrey Lopez, Jurgis Ruza, Michael A. Stolberg, Richard Osterude, Jeremiah A. Johnson, Rafael Gomez-Bombarelli, Yang Shao-Horn
Summary: Solid polymer electrolytes (SPEs) have the potential to improve lithium-ion batteries by enhancing safety and enabling higher energy densities. A chemistry-informed machine learning model was developed to predict ionic conductivity of SPEs, using data from hundreds of experimental publications. The model encodes the Arrhenius equation into the readout layer of a neural network and has improved accuracy in predicting ionic conductivity.
ACS CENTRAL SCIENCE
(2023)
Article
Chemistry, Physical
Matthew A. Pearson, Sachin Bhagchandani, Mircea Dinca, Jeremiah A. Johnson
Summary: A strategy of mixing multivalent polymer ligands with MOF-forming linkers and free linkers is investigated to alter the degree of polymer incorporation in polyMOFs and tune their properties, resulting in polyMOFs with superior N-2 and CO2 uptake. The mixed ligand approach is further extended to create multivariate (MTV)-polyMOFs without the addition of small molecule components.
MOLECULAR SYSTEMS DESIGN & ENGINEERING
(2023)
Article
Chemistry, Multidisciplinary
Herbert Wakefield, Ilia Kevlishvili, Kelsie E. Wentz, Yunxin Yao, Tatiana B. Kouznetsova, Sophia J. Melvin, Em G. Ambrosius, Abraham Herzog-Arbeitman, Maxime A. Siegler, Jeremiah A. Johnson, Stephen L. Craig, Heather J. Kulik, Rebekka S. Klausen
Summary: The cis- and trans-isomers of a silacycloheptene were selectively synthesized using a silyl dianion, providing a novel method for studying strained cycloalkenes. Quantum chemical calculations and crystallographic signatures confirmed that the trans-isomer is more strained than the cis isomer. The trans-isomer also exhibited unique reactivity in ring-opening metathesis polymerization (ROMP) and showed increased molecular compliance compared to carbon-based analogues.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Polymer Science
Haley K. Beech, Jeremiah A. Johnson, Bradley D. Olsen
Summary: Small angle neutron scattering was used to measure the single chain radii of gyration of end-linked polymer gels before and after cross-linking. The prestrain, which is the ratio of the average chain size in a cross-linked network to that of a free chain in solution, increased as gel synthesis concentration decreased near the overlap concentration. Dilute gels with higher loop fractions were found to be spatially homogeneous. The results provide a reference for network theories that rely on prestrain for the calculation of mechanical properties.
Article
Chemistry, Multidisciplinary
Alayna M. Johnson, Jeremiah A. Johnson
Summary: Bifunctional silyl ether (BSE)-containing high-density polyethylene (HDPE)-like materials have been synthesized under mild polymerization and hydrogenation conditions. Both the concentration of BSEs in the polymer chain and the silicon steric bulk can be tuned to yield materials with HDPE-like thermomechanical properties. The materials undergo two distinct deconstruction pathways and can be recycled without compromising their mechanical strength.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Michael A. Stolberg, Benjamin A. Paren, Pablo A. Leon, Christopher M. Brown, Gavin Winter, Kiarash Gordiz, Alberto Concellon, Rafael Gomez-Bombarelli, Yang Shao-Horn, Jeremiah A. Johnson
Summary: Solid polymer electrolytes have the potential to enable safer and more energy-dense batteries. This study investigates the impact of anion dissociation energy on ion conduction in solid polymer electrolytes. The researchers developed ionenes with various cations and found that the addition of a cation-coordinating solvent greatly enhanced ionic conductivity without disrupting the lamellar structure. This work demonstrates that molecular design can facilitate significant improvements in ion conduction in solid polymer electrolytes.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Polymer Science
Tetsu Ouchi, Wencong Wang, Brooke E. E. Silverstein, Jeremiah A. A. Johnson, Stephen L. L. Craig
Summary: The influence of strand length on deformation and tension in a polymer network was studied using mechanophore force probes. It was found that the critical strain at which measurable mechanochromism is observed is correlated with the strain hardening of the matrix, but independent of the molecular length of the probes. The rate of decoloration during relaxation of the network was found to depend on the relaxing strain, indicating the effect of residual tension on the reversion reaction.
Article
Chemistry, Multidisciplinary
Keith E. L. Husted, Abraham Herzog-Arbeitman, Denise Kleinschmidt, Wenxu Zhang, Zehao Sun, Alyssa J. Fielitz, An N. Le, Mingjiang Zhong, Jeremiah A. Johnson
Summary: Based on experimental results from a library of 92 polynorbornene-graft-polydimethylsiloxane (PDMS) copolymers, a versatile backbone-pendant sequence-control strategy is discovered, which provides a simple method for precisely controlling the thermomechanical and morphological properties of graft copolymers. Small structural variations of pendant groups in small-molecule comonomers have significant impacts on various properties of silicone-based graft copolymers, resulting in a wide range of designable materials properties. This study reveals a new pendant-group-mediated self-assembly strategy that simplifies graft copolymer synthesis and enables the development of a diverse family of silicone-based materials with tailored performance specifications.
ACS CENTRAL SCIENCE
(2023)
Article
Chemistry, Organic
Landon J. Kilgallon, Yang Shao-Horn, Jeremiah A. Johnson
Summary: A simple and scalable method for synthesizing DMTMSA and other trifluoromethanesulfonamide solvents is described. No specialized glassware is needed, and water is used as the solvent with an ice bath for cooling. The optimized process is highly efficient and reduces waste.
JOURNAL OF ORGANIC CHEMISTRY
(2023)