Physical Chemistry Commons^™

Exploring The Geometric And Electronic Properties Of Palladium Doped Silicon Clusters, Madison Winkeler, Ciara N. Richardson

Scholars Week

Transition metal-doped silicon clusters have unique properties and have been studied as building blocks for nanomaterials and microelectronics. Here, the structure and properties of candidate palladium doped silicon clusters (SinPd2: n=1-17) were determined using global optimization techniques on a high performance computing cluster at the San Diego Supercomputing Center. Then geometric structures were further optimized utilizing the B3LYP method with 6-311+G(d) basis sets for silicon and lanl2dz pseudopotential for palladium, followed by the larger DSDPBEP86 method with 6-311+G(2d) basis sets for silicon and SDD pseudopotential for palladium, as implemented in the Gaussian 16 program package. The energetics for each cluster …

Investigating The Proton Transfer Dynamics And Vibrational Spectrum Of Hydrogen Oxalate Using Driven Molecular Dynamics Simulations, Martina Kaledin, Dominick Pierre-Jacques, Olivia Cochran, Dayana Salazar, Dalton Boutwell, Martina Kaledin

Symposium of Student Scholars

In this computational chemistry work, we describe ab initio calculations and assignment of infrared (IR) spectra of an intramolecular H-bonding system hydrogen oxalate, C₂O₄H^–. The mechanism and dynamics of proton transfer are of fundamental importance in chemistry and biology. In C₂O₄H^–, proton transfer occurs along the non-linear path. Previous experimental studies are signaling very strong coupling between OH stretch mode and low frequency motions. We calculated IR spectra at 300 K using the direct molecular dynamics (MD) method at the MP2/ aug-cc-pVDZ level of theory and assigned the …

Molecular Vibrations Of Symmetric Molecules: Raman Scattering Driven Molecular Dynamics Method, Martina Kaledin, Dominick Pierre-Jacques, Ciara Tyler, Jason Dyke

Symposium of Student Scholars

This project focuses on developing a novel computational technique to study molecular vibrations through infrared (IR) and Raman scattering Driven Molecular Dynamics (DMD) method. While the main criterion for IR absorption is a net change in the dipole moment in a molecule as it vibrates, presently we wish to predict and analyze vibrational spectra to study symmetric vibrational modes that are IR inactive or weakly active while strongly Raman active. A newly developed method was tested on CO₂, H₂O, CH₄, and C₂₀ molecules. Students optimized the molecular structures, obtained vibrational frequencies, and IR …

Probing Structure And Energetics Of Proton-Bound Complexes N2…Hco+ And N2h+…Oc Using Computational Chemistry Methods, Antonio Barrios, Dalton Boutwell, Onyi Okere, Monique Olocha, Oluwaseun Omodemi, Alexander Toledo, Antonio Barrios

Symposium of Student Scholars

N₂…HCO⁺ and N₂H⁺…OC are predicted to exist in interstellar clouds. These complexes involve HCO⁺ and N₂H⁺ fragments that are bound to N₂ and CO, respectively using hydrogen-bonded interaction. The reason these molecules are important is that the existence of nitrogen can be measured indirectly through ion-molecular complexes studied in this work. The measured vibrational spectra of molecules is an excellent way to characterize and detect molecules. We used B3LYP, MP2, and CCSD(T) computational methods to predict the structure and vibrational frequencies of N₂…HCO⁺ and N …

Theoretical Study On The Isomerization And Detection Of N2h+…Oc Complex In Interstellar Clouds, Dalton Boutwell, Martina Kaledin

Symposium of Student Scholars

In this study, we characterize N₂H⁺…OC linear complex using Driven Molecular Dynamics (DMD) and Vibrational Self-Consistent Field Theory (VSCF) methods due to its relevance in astrochemistry. A central challenge is the detection of the molecular complex in interstellar media (ISM). Computational chemistry approaches can predict vibrational spectra, hence facilitate prediction of its existence and stability in the ISM. N₂H⁺…OC involves the proton transfer process via hydrogen bonding interaction. Proton motion is highly anharmonic, therefore facing a significant challenge to characterize it accurately. Quantum mechanical variational methods are popular among many theoretical chemists …

Elucidation Of The Combination Bands And Anharmonic Features In The Vibrational Spectra Of C2o4h- And C2o4d- With Driven Classical Trajectories, Dalton Boutwell, Martina Kaledin

Symposium of Student Scholars

Hydrogen bonds are strong electrostatic interactions characterized by the anharmonic shift of vibrational modes of atoms involved with this intramolecular force. The low energy barrier of the H⁺ transfer in hydrogen oxalate (C₂O₄H^-), predicted to be ~2.98 kcal/mol at the MP2/aVDZ level of theory, allows for rapid proton exchange in the system and confounds the experimental vibrational spectrum of the molecule with broad spectral features in the O-H stretching region. The molecule is planar and exhibits several torsional motions among some of its lower frequency fundamental vibrational transitions. Because H-bonding and torsional motions …

Model Calculations Of H/D Isotope Substitution In Hydrogen Oxalate Anion Using The Normal Mode Analysis, Dominick Pierre-Jacques, Olivia Cochran, Dayana Salazar, Martina Kaledin

Symposium of Student Scholars

In this computational chemistry work, we describe ab initio calculations and assignment of infrared (IR) spectra of an intramolecular H-bonding system hydrogen oxalate, C₂O₄H^–. The study of H/D isotope effects can provide useful information on a proton’s location inside a non-linear pathway. In C₂O₄H^–, a normal mode analysis was performed at the MP2/aug-cc-pVDZ and B3LYP/aug-cc-pVDZ levels of theory. Previous experimental studies suggest a frequency shift ~1000 cm^-1 for the OH stretch mode upon the H/D isotopic substitution. Isotope calculations resulted in a shift of 842 cm^{-1 …}

Transmission Ir Of Phosphorus In Water-Ice, Kerrigan Greene

Symposium of Student Scholars

The possibility of life on other planets has prompted philosophical debate and scientific research for years. As more of space is explored, and more is discovered about the origin of life, various planets and moons have come under speculation for the possibility of life. The icy moons of Saturn and Jupiter are prime examples. This is because of the presence of water-ice on their surfaces. However, there are many other important chemicals and elements necessary for life to develop and thrive. One such element is phosphorus. In order to analyze the ice on the surface of these moons and other …

The Reactivity Of Metal Phosphites: Oxidative Rate Analysis, Jamie Kitchens

Symposium of Student Scholars

Phosphorous compounds are involved in many of the biomolecular processes deemed fundamental for life. DNA, ATP, and phospholipids are a few of the molecules where phosphates can be found in the body. Phosphates are geochemically characterized by their low solubility and poor reactivity. This has led to the investigation of reaction mechanisms that could lead to the formation of the phosphorous compounds found in organisms. The oxidation of phosphite into phosphate could be how phosphates were introduced to life, due to phosphites being more soluble and more reactive than phosphates. We will present the synthesis and oxidation reactivity of four …

Energy Requirements For Abiotic Production Of Phosphorous Compounds At The Ice-Schreibersite Interface, Lindsay M. Hicks

Symposium of Student Scholars

Energy Requirements for Abiotic Production of Phosphorous Compounds at the

Ice-Schreibersite Interface

The Abbott-Lyon Lab is investigating the chemistry at the interface of simple ices and a meteoritic mineral analogue. Phosphorous is a key component of numerous biomolecules necessary for life. Lack of an abundance of biologically accessible mineral sources of phosphates on Earth, termed “The Phosphorous Problem,” has led some origin-of-life scientists to look to extraterrestrial sources like meteoritic metal phosphides as possible sources of available phosphates. Schreibersite (Fe₂NiP) is a common mineral in iron meteorites and a plausible source of biologically accessible phosphorous. This study will …

Investigation Of Chemistry At Ice-Mineral Interfaces Of Phosphorus-Containing Meteorites Analogues, Kimberly Meyberg

Symposium of Student Scholars

The search for life outside of Earth has raised questions about how life began have intrigued origin-of-life researchers, such as the incorporation of phosphorus into biomolecules. Phosphorus exists on Earth mostly as phosphate, PO₄^3-, which is insoluble and unreactive in the geochemical conditions of the early Earth. The challenge of incorporating phosphorus into biomolecules is known as the “phosphorus problem,” prompting investigations of reactive phosphorus species delivered to the prebiotic Earth. Phosphorus-laden meteorites delivered schreibersite (Fe,Ni)₃P, a possible mineral source of phosphorus recognized for its redox chemistry potential and observed reactivity with aqueous …

062— Nano-Size Dependence In Aggregation Process Of Beta 2 Microglobulin Coated Gold Colloids, Kaylee A. Hausrath

GREAT Day Posters

The formation of the aggregates of the beta 2 microglobulin (b2m) coated nano-gold colloids were investigated for various nanogold colloid sizes ranging between 10 nm and 100 nm. The aggregation process was considered to be initiated by the selfassembly of b2m by transforming the folded to the unfolded structure under highly acidic condition (pH < 4). The formation of the aggregates were monitored by a peak shift of surface plasmon resonance (SPR) band as a function of number of free b2m available. As for relatively smaller size of gold colloid diameter a gradual aggregation process was observed. The size of the aggregates was considered to increase monotonically as the b2m was added. On the other hand, as for relatively larger diameter of gold colloid, stepwise aggregation process was observed. So that the aggregates of a particular size was formed at a certain threshold of the concentration of available free b2m. The majority of the gold surface of the smaller gold size was easily covered and support the aggregation even at the lower concentration of b2m.

Acid Catalyzed Small Ring Alcohols And Alkenes: An Artistic Approach To Visualizing Relationships Between Features Produced By Uv-Visible Spectra, Madeleine Ware

Campus Research Day

Madeleine Ware

Research Description

Campus Research Day

My physical organic chemistry research was supervised by Dr. Mitch Menzmer who studies the formation of carbocation intermediates in acid-catalyzed reactions of alkylated and non-alkylated small ring alcohols. The goal of my work was to compile data and develop methods to search for relationships between the initial structures of molecules analyzed and the wavelengths of maximum absorbance for features observed within a given spectrum. In addition, my advisor from the School of Visual Art and Design, Associate Professor Marc Boyson, contributed to this process by providing insights about the way information could be …

Products Of An Acid-Catalyzed 1-Methylcyclopentene Reaction, Erin Burke

Campus Research Day

The poster presents research on the alternate products produced from 1-methylcyclopentene across different concentrations of sulfuric acid catalyst.