Chemistry Commons^™

Push-Pull Molecules: Models And Polymer Building Blocks For Organic Photovoltaic Applications, Raymond Devaughn

Masters Theses 1911 - February 2014

Several fluorenone alkynyl based oligo conjugated molecules were synthesized and characterized. Most compounds exhibited UV-Vis absorption onset at ca. 500 nm and a PL emission onset of ~329-370 nm, with excimer emission suspected from most systems near ~530-560 nm. Experimentally determined E_HOMO and E_LUMO energies range from -6.02 to -5.73 eV and -3.47 and 3.55 eV, respectively, with the lowest experimental E_g lying at -2.26 eV for 2-(trimethoxyphenylacetylene)-fluorenone. Cyclic voltammetry indicates quasi-reversible reduction for all systems, with 2,7-bis(nitrophenylacetylene)fluorenone exhibiting a high reduction potential of -1.25 eV. Only 2,7-bis(trimethoxyphenylacetylene)fluorenone exhibited a quasi-reversible oxidation, due to electron rich methoxy …

Resin Volatiles Of Eastern Hemlock Induced By Its Non-Native Herbivores, Joshua D. Pezet

Masters Theses 1911 - February 2014

Eastern hemlock (Tsuga canadensis) is in decline because of infestation by the invasive hemlock woolly adelgid (Adelges tsugae; ‘HWA’) and, to a lesser extent, the elongate hemlock scale (Fiorinia externa; ‘EHS’). Many conifers respond to insect herbivory by inducing oleoresin-based defenses, however it is unknown whether eastern hemlock is capable of this inducible response. We conducted a plantation setting study of artificially infested saplings to determine if feeding by HWA or EHS induces changes in the tree’s volatile chemistry. The induced changes in volatiles we found were unlike the terpenoid-based defenses of related conifers. Only HWA feeding …

Synthesis Of Monomers For New Conjugated Polymers, Kedar Girish Jadhav

Masters Theses 1911 - February 2014

ABSTRACT

SYNTHESIS OF MONOMERS FOR NEW CONJUGATED POLYMERS

This dissertation addresses the problem of synthesis of different monomers for donor and acceptor polymers in photovoltaic applications. In general, functionalization of conjugated polymers and understanding of molecular packing of electron donors and electron acceptors are very important to produce efficient solar cells. As a result, it is important to design and synthesize novel monomers which will require making new π-conjugated donors and acceptors polymers and understand the influence of these new polymers in bulk heterojunction to design polymer solar cells. In this study, two different monomers were synthesized. The first monomer …

A Paleoclimate Modeling Experiment To Calculate The Soil Carbon Respiration Flux For The Paleocene-Eocene Thermal Maximum, David M. Tracy

Masters Theses 1911 - February 2014

The Paleocene-Eocene Thermal Maximum (PETM) (55 million years ago) stands as the largest in a series of extreme warming (hyperthermal) climatic events, which are analogous to the modern day increase in greenhouse gas concentrations. Orbitally triggered (Lourens et al., 2005, Galeotti et al., 2010), the PETM is marked by a large (-3‰) carbon isotope excursion (CIE). Hypothesized to be methane driven, Zeebe et al., (2009) noted that a methane based release would only account for 3.5°C of warming. An isotopically heavier carbon, such as that of soil and C3 plants, has the potential to account for the …

Electronic And Vibrational Spectroscopy Of Ni+(H2o), Jennifer S. Daluz

Masters Theses 1911 - February 2014

The electronic and vibrational spectra of Ni⁺(H₂O) were measured using photofragment spectroscopy. In the electronic spectrum, photodissociation is observed at photon energies above 16875 cm^-1. The only fragment observed is Ni⁺. The electronic spectrum consists of well-resolved peaks spaced by ~340 cm^-1, due to a vibrational progression in the excited electronic state. These peaks have complex sub-structure, consisting of a triplet, spaced by ~30 cm^-1. The sub-structure is due to rotational structure in a perpendicular transition of a prolate top molecule. In addition to this major progression, there …

Pharmacological Chaperoning In Fabry Disease, Jerome Rogich

Masters Theses 1911 - February 2014

Fabry Disease is an X-­‐linked lysosomal storage disorder characterized by a variety of symptoms including hypohydrosis, seizures, cardiac abnormalities, skin lesions, and chronic pain. These symptoms stem from a lack of functional endogenous α-­‐ Galactosidase A (α-­GAL), which leads to an accrual of its natural substrate. The severity of the disease symptoms can be directly correlated with the amount of residual enzyme activity. It has been shown that an imino sugar, 1-deoxygalactonojirimycin (DGJ), can increase enzymatic activity and clear excess substrate. This pH-­‐dependent chaperoning phenomenon is believed to arise from the presence of aspartic acid 170 in the active site. …

Attenuation Of Acid Mine Drainage Enhanced By Organic Carbon And Limestone Addition: A Process Characterization, Anna M. Gillmor

Masters Theses 1911 - February 2014

Surface and groundwaters in contact with mining-exposed pyritic materials have the capacity to generate acid mine drainage (AMD), an acidic, sulfate-rich, metals-laden effluent. The Davis Mine located in northwestern Massachusetts offers a model site to study the processes of natural attenuation of acid mine drainage. These include physico-chemical processes such as dilution and sorption, geochemical processes such as aluminosilicate weathering and biological processes such as transformation and cycling of sulfate, iron and acidity by bacterial metabolism. A focus of recent research undertaken at the site has been characterizing the presence and activity of these bacteria with an aim to stimulate …

Sorption Of Bovine Serum Albumin On Nano And Bulk Oxide Particles, Lei Song

Masters Theses 1911 - February 2014

Manufactured oxide nanoparticles (NPs) have large production and widespread applications, which will inevitably enter the environment. NPs can interact with proteins in living beings due to the fact that NPs can transport into blood or across cell membranes into cells. Conformational change of protein molecules after sorption on oxide NPs has been reported. Therefore, it is important to understand the adsorption mechanism of protein onto oxide NPs surfaces. Although few works have reported protein adsorption behaviors, a general systematic comparison of the effects of particle size and surface groups on protein adsorption by widely studied NPs still needs to be …

Nitrogen Dioxide In The Urban Forest: Exposure And Uptake, Tanner B. Harris

Masters Theses 1911 - February 2014

Nitrogen dioxide (NO2) levels were measured inside and adjacent to canopies of urban trees in Springfield, MA, over two growing seasons. Nitrogen dioxide levels were consistently and significantly higher inside tree canopies compared to levels outside. During the second growing season, ozone (O3), temperature, and relative humidity (RH) were also measured using samplers co-located with the NO2 samplers. Ozone levels were significantly lower inside the canopy whereas temperatures were higher inside the canopy, and RH was not different between inner and outer canopy locations. The results corroborate theoretical models predicting elevated NO2 and depressed O3 levels inside tree canopies based …