Chemistry Commons^™

3d Pictorial Representations Of O2- And Ho2 Compared To Dft Results, Tzu-Hsiang Huang, Joseph D. Alia

Chemistry Publications

The Linnett Double Quartet (LDQ) (1) and Bohr Orbit Bonding (BOB) (2) methods were used to accurately represent the spin density distribution for superoxide (O2 -) and hydroperoxyl radical (HO2). These structural pictures were superimposed on the spin density plot produced by DFT. The Valency Interaction Formula (VIF) method (3) was also applied to these molecules and it matched the NBOs from NBO analysis of DFT results. The interaction between O2 - and H2O were analyzed and the stronger basicity of the beta-spin electrons of superoxide was identified by looking at the LDQ structure and confirmed with NBO analysis. The …

Two-Electron Density Of Three Electrons In A 1d Box: A Model System For Visualizing Spin Correlation Due To Antisymmetry Of Electrons, Joseph D. Alia

Chemistry Publications

Visual models for understanding electron density distribution in molecules are useful for chemical reasoning. The Lewis structure for example compares well to one-electron density when all electrons are paired. Linnett Double Quartet structures compare well to some kinds of free radical species. These approaches do not show the behavior of the total electron wavefunction when two electrons near each other. This behavior is a two- electron property and can be visualized with the model of three electrons in a one- dimensional box. The two-electron density of the three electron wavefunction described as a slater determinent of 1D particle-in-a-box spin- orbitals …

Synthesis Of Benzophenone-O-Glycosides Under Basic Conditions, Samuel Burns

Undergraduate Research Symposium 2022

Type 2 diabetes is a growing health concern worldwide characterized by high blood sugar. Anti-diabetic therapy aims at correcting this sugar imbalance by inhibiting the enzyme α-glucosidase which is responsible for cleaving carbohydrates and starch into glucose. Benzophenone glycosides are a class of biomolecules with α-glucosidase inhibitory properties that have garnered some attention. It can be found and isolated from some traditional medicinal plants which was not done for this project. Once isolated, new derivatives can be synthesized by manipulating protecting groups of the starting material to get the benzophenone. The benzophenone can then undergo glycosylation with the protected sugar …

Co2 Capturing Materials, Isaac Sanchez

Undergraduate Research Symposium 2021

Greenhouse gas emissions are one of, if not the major cause of global warming. With CO₂ emissions rising annually, it is paramount to selectively capture and remove CO₂ from flue gas. One method of capturing CO₂ gas is via porous materials. Covalent organic frameworks (COFs) are porous materials which have been explored throughout this research. Two important features of COFs are the base unit linkage types (BULTs) and the functional groups attached to the organic linkers (OLs). The BULT used in this research was a covalent triazine framework (CTF) and the main functional group used in the …

Synthesis Of Transfer Hydrogenation Catalysts Containing Unsymmetrical Bisphosphines, Nora Fritz

Undergraduate Research Symposium 2021

Asymmetric catalysis, where a metal catalyst is used to transform a substrate into a single enantiomer of product, has become a popular synthetic technique in both academic and industrial settings. An enantiomer is a single molecule with a unique three-dimensional shape with a mirror image not superimposable on the original. The chirality, or right or left-handedness, of compounds lead to applications important in the pharmaceutical and agrochemical industries. Commonly, a metal complex’s ability to create a product of a certain enantiomer relies on a chiral group being attached to the metal. However, having the chirality of a metal complex depend …

Anion Removal By Partially Positive Adsorbents, Breanna Dragseth, Matt Desmith, Emily Robinson, Abi Bartlett

Undergraduate Research Symposium 2021

Nitrates and phosphates exist naturally but are present in elevated concentrations in many areas primarily due to agriculture; these elevated concentrations are concerning for human and environmental health. The project considered the ability of four different materials used for adsorption (adsorbents) to adsorb nitrate and phosphate. All adsorbents had a silica base with an amine (NH2) group and were further functionalized with different ligands consisting of an aromatic ring functionalized with electron withdrawing groups, creating a partial positive environment to help attract the anions of interest. We also synthesized control materials to determine how effective our engineered materials are. The …

Unspecified Verticality Of Franck-Condon Transitions, Absorption And Emission Spectra Of Cyanine Dyes, And A Classically Inspired Approximation, Joseph D. Alia, Joseph A. Flack

Chemistry Publications

The computed vertical energy, Ev,a/f, from the equilibrium geometry of the initial electronic state is frequently considered as representative of the experimental excitation/emission energy, Eabs/fl = hc/λmax. Application of the quantum mechanical version of the Franck–Condon principle does not involve precise specification of nuclear positions before, after, or during an electronic transition. Moreover, the duration of an electronic transition is not experimentally accessible in spectra with resolved vibrational structure. It is shown that computed vibronic spectra based on TDDFT methods and application of quantum mechanical FC analysis predict Eabs = hc/λmax …

Direct Arylation Polymerization Of Indophenine-Based Monomers, Sarah Severson

Student Research, Papers, and Creative Works

Indophenine, a deep blue dye and a quinoidal compound, has shown potential as a monomer in donor-acceptor copolymer formation for use in energy and device applications. Despite the barrier of low solubility, we previously polymerized an indophenine-based monomer IQ to form PolyIQ-co-thiophene (PIQ) in a 95% yield using Stille coupling. Although PIQ has desirable electronic properties, Stille coupling is a particularly unsustainable method. In contrast, direct arylation polymerization (DArP) is a more sustainable polymerization method that reduces synthetic steps and toxic byproducts. Therefore, we now report the DArP of IQ to form PolyIQ-co-ProDOT (ProPIQ) in a 96% yield. ProPIQ boasts …

Quantum Chemical Lipophilicities Of Antimalarial Drugs In Relation To Terminal Half-Life, Joseph D. Alia, Sheila Karl, Tyler D. Kelly

Chemistry Publications

According to the WHO, artemisinin-based combination therapies (ACTs) have been integral to the recent reduction in deaths due to Plasmodium falciparum malaria. ACT-resistant strains are an emerging problem and have evolved altered developmental stages, reducing exposure of the most susceptible stages to artemisinin drugs in popular ACTs. Lipophilicity, log K_ow, is a guide in understanding and predicting pharmacokinetic properties such as terminal half-life which alters drug exposure. Consistent log K_ow values are not necessarily available for artemisinin derivatives designed to extend terminal half-life, increase bioavailability, and reduce neurotoxicity. For other drugs used in ACTs, an assortment of …

Synthesis Of Unsymmetrical Bidentate Ligands From Secondary Phosphine Oxides, Malachy J. Brink, Ryan Anderson

Student Research, Papers, and Creative Works

Stereochemistry is a key component in the field of asymmetric catalysis. The properties of a molecule can be drastically changed with the change of one stereocenter. Typically, chirality is imparted to a metal by the ligand. "Chiral-at-metal" compounds are unique because the metal complex is chiral, but the ligands are not. Phosphine ligands are notoriously difficult to work with (pyrophoric, toxic, prone to oxidation). The goal of this research was to prepare unsymmetrical bidentate ligands using secondary phosphine oxides, which are air-stable and easy to handle on the benchtop.

Synthesis Of Unsymmetrical Bis(Phosphine) Oxides And Their Phosphines Via Secondary Phosphine Oxide Precursors, James R. Pedroarena, Bryan P. Nell, Lev N. Zakharov, David R. Tyler

Chemistry Publications

The unsymmetrical bidentate phosphine ligands (Me)₂PCH₂CH₂CH₂P(Et)₂ (14), (Me)₂PCH₂CH₂CH₂P(iPr)₂ (15), (Me)₂PCH₂CH₂CH₂P(Cy)₂ (16), and (Me)₂PCH₂CH₂CH₂P(Ph)₂ (17) were synthesized using air–stable phosphine oxide intermediates. In the first step, sodium phosphinites formed by deprotonation of (Me)₂P(O)H, (Et)₂P(O)H, and (iPr)₂P(O)H were alkylated by 1-bromo-3-chloropropane. The different substitution rates of the chloride and bromide groups allowed the isolation of the intermediates (Me)₂P(O)CH …

Acid-Mediated N-Iodosuccinimide-Based Thioglycoside Activation For The Automated Solution-Phase Synthesis Of Α-1,2-Linked-Rhamnopyranosides, Victoria R. Kohout, Alyssa L. Pirinelli, Nicola L.B. Pohl

Chemistry Publications

Carbohydrate structures are often complex. Unfortunately, synthesis of the range of sugar combinations precludes the use of a single coupling protocol or set of reagents. Adapting known, reliable bench-chemistry reactions to work via automation will help forward the goal of synthesizing a broad range of glycans. Herein, the preparation of di- and tri-saccharides of alpha 1→2 rhamnan fragments is demonstrated using thioglycoside donors with the development for a solution-phase-based automation platform of commonly used activation conditions using N-iodosuccinimide (NIS) with trimethylsilyl triflate. Byproducts of the glycosylation reaction are shown to be compatible with hydrazine-based deprotection conditions, lending broader functionality …

Organic Chemistry With A Biographical Emphasis: Solutions To In-Chapter Exercises, Timothy Soderberg

Chemistry Publications

The solutions to the in-chapter exercises of Organic Chemistry with a Biological Emphasis volume 1 and 2.

Organic Chemistry With A Biological Emphasis: Solutions To Selected End-Of-Chapter Problems, Timothy Soderberg

Chemistry Publications

The solutions to the in-chapter exercises of Organic Chemistry with a Biological Emphasis volume 1 and 2.

Organic Chemistry With A Biological Emphasis Volume Ii, Timothy Soderberg

Chemistry Publications

The traditional approach to teaching Organic Chemistry, taken by most of the textbooks that are currently available, is to focus primarily on the reactions of laboratory synthesis, with much less discussion - in the central chapters, at least - of biological molecules and reactions. This is despite the fact that, in many classrooms, a majority of students are majoring in Biology or Health Sciences rather than in Chemistry, and are presumably taking the course in order to learn about the chemistry that takes place in living things.

In an effort to address this disconnect, I have developed a textbook for …

Organic Chemistry With A Biological Emphasis Volume I, Timothy Soderberg

Chemistry Publications

The traditional approach to teaching Organic Chemistry, taken by most of the textbooks that are currently available, is to focus primarily on the reactions of laboratory synthesis, with much less discussion - in the central chapters, at least - of biological molecules and reactions. This is despite the fact that, in many classrooms, a majority of students are majoring in Biology or Health Sciences rather than in Chemistry, and are presumably taking the course in order to learn about the chemistry that takes place in living things.

In an effort to address this disconnect, I have developed a textbook for …

Intermolecular-Trapping Of 1,3-Dialkyl Diaziridines With Hdda-Derived Benzynes, Ramitha Rupasinghe

Undergraduate Research Symposium 2018

The extent to which benzynes react with various trapping agents is an important question in synthetic chemistry due to its versatility to produce products that can be used as pharmaceuticals, dyes and other complex molecules. The hexadehydro-Diels-Alder (HDDA) reaction allows the generation of benzynes in situ which then can be efficiently trapped to synthesize complex products in one step with high yields. Reactions of HDDA - derived benzynes with trapping agents such as thioamides, alcohols, pyrroles, silyl ethers and multifunctional natural products have been studied in previous research. In this research, the reactions of HDDA-derived benzynes with diaziridines is explored …

Investigation Of Hkust-1 And Related Composites With Protein Adsorption, Ramitha Rupasinghe

Undergraduate Research Symposium 2017

Metal Organic Frameworks (MOFs) possess well-ordered porous structures that have been shown to adsorb proteins. MOFs can be enhanced by combining them with suitable materials to make composites. Enhancements include, but are not limited to, changing pore sizes, adding functional groups, improving selectivity of adsorption, and increasing stability. Previous research has shown high adsorption of proteins by the MOF, HKUST-1 but no research has been done to investigate the adsorption by its related composites, such as HKUST-1/GO, HKUST-1/ magnetite and HKUST-1/magnetite/GO. In this research, HKUST-1 and composites based on graphene oxide (GO) and magnetite were synthesized, characterized by FTIR, XRD …

Optimization Of Mangosteen Dye-Sensitized Solar Cells, Hannah Goemann

Undergraduate Research Symposium 2016

Garcinia mangostana, commonly known as mangosteen, is often referred to as the “queen of fruits” for its delicious flavor and numerous health benefits. Mangosteen has also attracted attention in recent dye-sensitized solar cells (DSSC) studies as the dye extracted from the fruit’s purple-red pericarp has exceeded many natural dyes in DSSC efficiency. In short, this dye is promising for the development of a natural products-based, sustainable DSSC, as it is a highly effective transporter of photoexcited electrons into the solar cell to be converted into electricity. The purpose of this study was to optimize the dye extraction from the mangosteen …

Synthetic Methods Of Cts And Czts Nanocrystals, Rachel R. Bohling, Michael M. Davis, Blake J. Gerold, Ted M. Pappenfus

Undergraduate Research Symposium 2015

The synthesis of various morphologies of copper zinc tin sulfide (Cu2ZnSnS4) and copper tin sulfide (Cu2SnS3) nanocrystals were explored to find a more energy efficient synthesis. Reactions were all carried out at 220°C under either inert atmospheres or normal conditions. Variations in synthetic methods included reaction time and solvents used. Products were analyzed with powder X-Ray diffraction and compared to simulated powder patterns of zincblende and wurtzite nanocrystals. The synthesis of CTS nanocrystals required the reaction to be heated to 220°C overnight under an inert atmosphere. The reaction used for the synthesis of CZTS nanocrystals required less energy and only …

Modification Of Mof-5 Hydrostability For Peptide Absorption Studies, Margareta E. Nivision, Zachary L. Mensinger

Undergraduate Research Symposium 2015

Metal-organic frameworks (MOFs) are an intriguing class of hybrid materials that consist of infinite crystalline lattices formed by metal ions bridged by organic linkers. Their porous interiors have highly variable properties, depending on the metal ions and linkers used. To date, MOFs have primarily been examined for uses such as gas separation and storage and catalysis, but recently researchers have described the adsorption of proteins and peptides, such as cytochrome C and a trypsin digest of bovine serum albumin, in MOF pores. The MOF pore provides a stable, ordered environment in which to isolate and characterize peptides. Our research thus …

Computational Study Of The Visible Spectrum Of Curcumin's Protonation States, Peter Braegelmann, Joseph D. Alia

Chemistry Publications

Curcumin, the main dye in the important Indian spice turmeric, has received much attention recently for its potential anti-cancer and anti-Alzheimer properties.1 Our study computes the thermodynamics and spectroscopic properties of curcumin’s various protonation states using several methods and compares the results to experiment. M06/3-21G* gave the best thermodynamic results, while M06 with 3-21G* and 6-31G* gave good spectroscopic results for the neutral and dianionic forms of curcumin. However, applying diffuse functions appears to be necessary for the trianionic form. Interestingly, M06 and B3LYP with 6-31+G* gave good spectroscopic results for the singly anionic form.

Study Of The Protonation States Of The Curcumin Molecule And Their Visible Absorption Spectra In Aqueous Solution Using M06, Smd, And Tddft And Compared To Experiment, Joseph D. Alia, Peter Braegelmann, Timothy Roettgen, Hannah Goemann

Chemistry Publications

Curcumin, the primary natural dye from the spice turmeric, has been of recent interest due to its possible health benefits as an antioxidant and possible anti cancer and anti Alzheimer's properties. Limited solubility and instability in water are of primary importance when considering curcumin's possible uses as a pharmaceutical. DFT computations were carried out using B3LYP and MO6 density functionals and the SMD solvent model for water. TDDFT computations were carried out on geometries optimized in water as described by the SMD solvent model. It is found that M06 with the 3-21G* basis set and SMD solvent model gives accurate …

Comparison Of Two Methods Of Monitoring Corn Mash At Corn Plus Ethanol Plant, Lanay Walker

Undergraduate Research Symposium 2013

In the ethanol industry, several variables affect the amount and grade of ethanol that is produced which affects a plant’s ability to make a profit. This research is focused on one of those variables, ‘corn mash solid content’, which must be closely monitored before the fermentation step. If the mash out of the mix tank is the wrong consistency, the alpha-amylase and gluco-amylase enzymes will not efficiently break the starch into simple sugars that yeast can consume which will decrease the amount of ethanol produced. The mash solid and moisture content is measured daily in order to ensure that the …

Chemical Reasoning Based On An Invariance Property: Bond And Lone Pair Pictures In Quantum Structural Formulas, Joseph D. Alia

Chemistry Publications

Chemists use one set of orbitals when comparing to a structural formula, hybridized AOs or NBOs for example, and another for reasoning in terms of frontier orbitals, MOs usually. Chemical arguments can frequently be made in terms of energy and/or electron density without the consideration of orbitals at all. All orbital representations, orthogonal or not, within a given function space are related by linear transformation. Chemical arguments based on orbitals are really energy or electron density arguments; orbitals are linked to these observables through the use of operators. The Valency Interaction Formula, VIF, offers a system of chemical reasoning based …

Pictorial Quantum Chemistry, Theory And Application Of Valency Interaction Formulas, Vif, Joseph D. Alia

Chemistry Publications

No abstract provided.

Borate Rods As An On-Site Remedial Treatment For Control Of Decay In Wood Decks, Mark G. Dietz, Elmer L. Schmidt

Journal of the Minnesota Academy of Science

A conventional wood recreational deck constructed with spruce-pine-fir lumber was sampled for active growth of wood decay fungi before and 10 months after remedial preservation treatment with fused disodium octaborate rods (IMPEL®) at boric acid levels from 1.5-10 kg/m3. Extent of boron distribution was observed with a color indicator dye (curcumin) after 10 months exposure. Remedial treatment with the boron rods. was nearly 100% effective. Active decay cultures from treated material were found only in samples obtained from boards treated at the inhibition dosage level (1.5kg/m3) of boric acid. Suggested lethal dosages (>3kg/m3) were effective in all cases as …

Here Is Where We Are, M. H. Baker

Journal of the Minnesota Academy of Science

Industrial chemistry in the Upper Midwest consists principally of compounding, formulating and specialty manufacturing rather than the production of basic chemicals. The economic position of industrial chemistry is, nevertheless, significant because many of the region's major corporations are employers of technically-trained personnel and are substantial chemical users. This paper provides a non-quantitative overview of chemical technology applications and developments in some of the area's key industries as a record of the past, a measure of current activity, and as a possible indicator for the future. The paper also notes that the large investment demands, complexity of regulations and distance from …

A Pycnometer Of Improved Design, Richard Moore

Journal of the Minnesota Academy of Science

The density of a solution must be known to laboratory medicine , biochemistry, and physical chemistry. Knowledge of the density may permit calculation of solution concentration, solute molecular weight, solute partial, or specific volume , for example. Therefore, the determination of the density of a solution is a measurement which must be made with precision, accuracy, and sensitivity. This report describes a pycnometer which permits making such measurements.

An Investigation Of Amino Acid Decomposition, Jack H. Frost, E. Winston Grundmeier

Journal of the Minnesota Academy of Science

Amino acid decarboxylation studies generally show that extraneous reactions accompany CO, formation, especially at high temperature and when metal ion catalysts are used. In the present study some of these reactions are investigated in the reaction system, a- or ,a-amino acid and CuSO, at 130-155° C. Histidine, a- and .B -alanine, glycerine and norvaline were each studied for determination of products. The extent of formation of the products, NH,, CO,, aliphatic amines and Cu metal, was determined quantitatively. A near l: l correspondence in NH,:CO2 exists for the amino acids studied. No correspondence could be detected between Cu metal product …