A5035726301- Spectroscopy and Quantum Chemical Studies
- Spectroscopy Techniques in Biomedical and Chemical Research
- Ionic liquids properties and applications
- Machine Learning in Materials Science
- Chemical Synthesis and Analysis
- Phase Equilibria and Thermodynamics
- Carbon Dioxide Capture Technologies
- Mineral Processing and Grinding
- Microbial Natural Products and Biosynthesis
- Protein Structure and Dynamics
- Photochemistry and Electron Transfer Studies
- Lipid Membrane Structure and Behavior
- Computational Drug Discovery Methods
- Electrochemical Analysis and Applications
- Soil Geostatistics and Mapping
- Advanced Photocatalysis Techniques
- 3D Modeling in Geospatial Applications
- Nonlinear Optical Materials Research
- Force Microscopy Techniques and Applications
- Mining Techniques and Economics
- Organoselenium and organotellurium chemistry
- Gold and Silver Nanoparticles Synthesis and Applications
- Problem and Project Based Learning
- Genomics and Phylogenetic Studies
- Synthetic Organic Chemistry Methods
Haverford College
2021-2025
Johns Hopkins University
2020-2024
University of Notre Dame
2016-2019
Gordon College
2015
Textbooks describe excess protons in liquid water as hydronium (H3O+) ions, although their true structure remains lively debated. To address this question, we have combined Raman and infrared (IR) multivariate curve resolution spectroscopy with ab initio molecular dynamics anharmonic vibrational spectroscopic calculations. Our results are used to resolve, for the first time, spectra of hydrated counterions reveal that there is little ion-pairing below 2 M. Moreover, find isolated strongly IR...
Prediction of organismal viability upon exposure to a nanoparticle in varying environments─as fully specified at the molecular scale─has emerged as useful figure merit design engineered nanoparticles. We build on our earlier finding that bag artificial neural networks (ANNs) can provide such prediction when machines are trained with relatively small data set (with ca. 200 examples). Therein, viabilities were predicted by consensus using weighted means predictions from bags. Here, we confirm...
The terminal alkyne C≡C stretch has a large Raman scattering cross section in the “silent” region for biomolecules. Experimental work taking advantage of this property provide an impetus development theoretical tools addressing vibration. In prior work, we have developed localized normal mode method computing vibrational frequencies using discrete variable representation potential energy surface. Using and molecular dynamics simulations, interpret unusually broad spectrum alkynes solvated...
Multi-point geostatistics is an algorithm which complements the traditional variogram driven cell-based and object modelling approaches to facies modelling. It situated somewhere between two, being a approach, but because it uses estimates of multi-variate distribution instead simple bi-variate distributions that are available variogramdriven algorithms, capable capturing geometries more similar those with This paper introduces reviews merits weaknesses this new method, particularly regard...
This work elucidates the molecular binding mechanism of CO2 in [C4C1IM][PF6] ionic liquid (IL) and its interplay with asymmetric stretch frequency ν3, establishes computational protocols for reliable construction spectroscopic maps simulating ultrafast 2D-IR data solvated ILs. While charge transfer drives static shift between different liquids (J. Chem. Phys. 2015, 142, 212425), we find here that electrostatic Pauli repulsion effects dominate dynamical geometries sampled from...
The primary challenge for connecting molecular dynamics (MD) simulations to linear and two-dimensional infrared measurements is the calculation of vibrational frequency chromophore interest. Computing at each time step simulation with a quantum mechanical method like density functional theory (DFT) generally prohibitively expensive. One approach circumnavigate this problem use spectroscopic maps. Spectroscopic maps are empirical relationships that correlate interest properties surrounding...
The anomalously high mobility of hydroxide and hydronium ions in aqueous solutions is related to proton transfer structural diffusion. role counterions these solutions, however, often considered be negligible. Herein, we explore the impact alkali metal counter cations on solvation mobility. Impedance measurements demonstrate that attenuated by lithium relative sodium potassium. These results are explained ab initio molecular dynamics simulations experimental vibrational hydration shell...
Machines consisting of bags artificial neural networks (ANNs) have been constructed to connect nanoparticle features the viability a broad class organisms upon exposure. The optimization these machines is based on relatively small data set. However, through consensus across bag ANNs, predict at level confidence comparable experiment and perform better than chance. mining machine feature space allows for discovery design rules nanoparticles with increased viability. As such, we demonstrate...
Molecular dynamics (MD) simulations validated against two-dimensional infrared (2D-IR) measurements of CO2 in an imidazolium-based ionic liquid have revealed new insights into the mechanism solvation. The first solvation shell around has a distinctly quadrupolar structure, with strong negative charge density carbon atom and positive near oxygen atoms. When is modeled without atomic charges (thus removing its quadrupole moment), weakens changes significantly structure that similar to N2 same...
In recent years, interest in carbon capture and sequestration has led to numerous investigations of the ability ionic liquids act as recyclable CO2-sorbent materials. Herein, we investigate structure dynamics a model physisorbing liquid, 1-butyl-3-methylimidazolium hexafluorophosphate ([C4C1Im][PF6]), from perspective CO2 using two-dimensional (2D) IR spectroscopy molecular simulations. A direct comparison experimentally measured calculated 2D line shapes confirms validity simulations...
Natural products have diverse chemical structures and biological activities which often serve as sources of new therapeutic agents. Those containing a carboxy-2H-azirine moiety are an exciting target for investigation due in part to the broad-spectrum antimicrobial activity these compounds significant space novel development offered by this unique scaffold. The moiety, including those appended well-characterized scaffolds, is understudied, creates challenge understanding potential modes...
The composition, orientation, and conformation of proteins in biomolecular coronas acquired by nanoparticles biological media contribute to how they are identified a cell. While numerous studies have investigated protein composition coronas, relatively little detail is known about the nanoparticle surface influences orientation associated with them. We previously showed that peripheral membrane cytochrome c adopts preferred poses relative negatively charged 3-mercaptopropionic acid...
In previous papers in the series, vibrational spectroscopy of CO2 ionic liquids (ILs) was investigated at ambient conditions. Here, we extend these studies to understand temperature dependence structure, dynamics, and thermodynamics 1-butyl-3-methylimidazolium hexafluorophosphate, [bmim][PF6], IL. Using spectroscopic mapping techniques, infrared absorption spectrum asymmetric stretch mode is simulated a number temperatures, results are found be consistent with similar experimental studies....
The prediction of organismal viability in response to exposure different nanoparticles and conditions characterized at the molecular scale is challenging because several orders magnitude must be bridged. A so-called bag artificial neural networks has recently been shown provide such a connection when trained through use relatively small databases. In present work, we found that individual do not always converge under training. bags weighted means for consensus predictions provides mechanism...
Multiple point geostatistics (MPS) is rapidly growing to become an established tool offering geologists and engineers a rich capacity construct geological models with quite complex geometries while conditioning potentially large amounts of well seismic data. Nonetheless, it still relatively new topic which, despite long gestation period in academic research, only now finding its way into commercial software. As such we can expect advances the science for several years come as becomes used...
The strategic redesign of microbial biosynthetic pathways is a compelling route to access molecules diverse structure and function in potentially environmentally sustainable fashion. promise this approach hinges on an improved understanding acyl carrier proteins (ACPs), which serve as central hubs pathways. These small, flexible mediate the transport molecular building blocks intermediates enzymatic partners that extend tailor growing natural products. Past combinatorial biosynthesis efforts...
The terminal alkyne C≡C stretch has a large Raman scattering cross section in the "silent" region for biomolecules. This led to many tag and probe studies using this moiety study biomolecular systems. A computational investigation of these systems is vital aid interpretation results. In work, we develop method computing vibrational frequencies isotropic transition polarizabilities that can easily accurately be applied any molecule. We apply discrete variable representation localized version...
Natural products containing the carboxy-2
The terminal alkyne C≡C stretch has a large Raman scattering cross section in the “silent” region for biomolecules. This led to many tag and probe studies using molecules with this moiety. Computational investigation of these systems is vital aid interpretation results. In work, we develop localized normal mode discrete variable representation (DVR) method computing vibrational frequencies transition isotropic polarizabilities which can easily accurately be applied any molecule. errors...
The terminal alkyne C≡C stretch has a large Raman scattering cross section in the “silent” region for biomolecules. This led to many tag and probe studies using molecules with this moiety. Computational investigation of these systems is vital aid interpretation results. In work, we develop localized normal mode discrete variable representation (DVR) method computing vibrational frequencies transition isotropic polarizabilities which can easily accurately be applied any molecule. errors...
Modeling of reservoirs has become more mathematically sophisticated over the last twenty years. In particular stochastic models have norm in very many, if not most reservoir studies. The reasons for this are threefold 1) advance modeling as a science exposed shortcomings implicit older deterministic models, namely underestimation role heterogeneity. 2) Stochastic methods provide best mechanism to incorporate various data types into model. 3) They allow some understanding and uncertainty...