Coastal forests in the southeastern and mid-Atlantic regions of the United States experience salinization and hydrologic alterations, leading to inland marsh migration and expanding ghost forests. Despite widespread tree mortality due to salinity intrusion, the processes driving tree decline and death in these systems are not fully known. Recent studies have indicated that salt exposure is associated with reduced wood density in loblolly pine (P. taeda), but the cause of this has not yet been found. We hypothesize that reduced lignin content, a compound that provides protection and rigidity, could be the source of wood density differences. To test this hypothesis, we compared lignin content from trees in the high-elevation forest (greater than 1m, with minimal salt exposure) and low-elevation forest (less than 0.7m, with high salt exposure) at three locations on the Delmarva Peninsula. We hypothesized that salt-exposed trees at Milford Neck, DE, Monie Bay, MD, and Brownsville Forest, VA have lower lignin content than their less-exposed upland counterparts due to reduced photosynthetic rates associated with salt stress, explaining the lower wood density found in these trees. Samples were collected by coring trees with an increment borer, and a modified acetyl bromide method was used to determine wood lignin content. Samples were restricted to trees with known wood density and cell morphology. Results from Monie Bay suggest lower lignin content in salt-exposed forest when compared to trees with lower salt exposure. Results from the Delaware and Virginia locations are pending.

While precious transition metals like palladium, rhodium, and iridium are highly successful in organic synthesis, their rarity, toxicity, and high cost call for greener alternatives. Earth-abundant first-row transition metals, particularly iron (Fe), have emerged as sustainable alternatives capable of vital transformations like cross-coupling and hydrosilylation. To match the performance of precious metals, iron requires significant steric stabilization, which can be achieved using bis(imino)acenaphthene (BIAN) ligand backbones. Asymmetrical Ar-BIAN ligands allow for better and more selective catalysts when considering iron catalysis. This work focuses on the creation and synthesis of Ar-BIANs and monoimine intermediates. Symmetric precursors were initially prepared by reacting acenaphthenequinone with the corresponding substituted anilines in the presence of ZnCl2​ in hot acetic acid. The resulting Ar-BIAN complexes were washed with diethyl ether, and recrystallized with dichloromethane to yield crystals. To date, the 3,5-(CF3)2C6H3-BIAN, 4-CF3-C6H4-BIAN, 3,5-Cl2-C6H3-BIAN, and 2,4-NO2-C6H3-BIAN have been successfully created and purified via recrystallization. Structural identities were confirmed via 1H, 13C, DEPT-90, DEPT-135, and 1H-13C HSQC NMR and further determined using melting points. Ongoing work includes assessing purity by melting point and elemental analysis of the crystals and ongoing work will also focus on the stepwise synthesis of the target asymmetric ligands by reacting acenaphthenequinone with one equivalent of a tert-butyl aniline to isolate the mono-imine intermediate, followed by condensation with the previously mentioned anilines. In the future, both the symmetric and non-symmetrical ligands will be bound to iron to evaluate their efficiency in catalytic transformations.

Conjugated Polymers (CPs) are semiconducting materials with the potential to be used in optoelectronic devices and bioelectronic interfaces due to their tunable electronic structure and mixed ionic-electronic transport properties. Since they are completely organic compounds, CPs offer many advantages over their inorganic (i.e. silicon) counterparts, such as biocompatibility and degradability. Donor-acceptor (D-A) architectures have been studied extensively as high performers for a variety of applications (i.e. bioimaging agents, solar cells, sensors etc.) due to their synthetically tunability. As a result of CPs having potential within biomedical devices, it is vital to elucidate their lifecycle from beginning to end-of-life. In this work, various analogues of scalable, high-performing D-A CPs were synthesized, controlling for the acceptor unit while varying the donor. Purification was standardized using sequential Soxhlet extraction to remove low molecular weight fractions and residual catalyst species. Molecular weight and dispersity were determined by gel permeation chromatography (GPC), optical properties were evaluated by UV-Vis and fluorescence spectroscopy, and electrochemical behavior was analyzed by cyclic voltammetry (CV). After each CP batch was fully characterized, they were each subjected to oxidative conditions similar to those found in biological conditions (i.e. H2O2). After complete degradation, a kinetic profile was determined for the suite of analogues, and chain scission was confirmed via post-degradation NMR spectroscopy and GPC.

The increased risk of exposure to waterborne illnesses through surface water systems remains a relevant public health issue in the United States. Aging water system infrastructure, fluctuating climate variation, agriculture, and recreational water usage have led to the persistence of infectious pathogens in rural and urban water sources. This study’s overall aim is to investigate microbial contamination of water sources in Minnesota. A first objective is to summarize the research evidence highlighting microbial contamination of water in Minnesota in the context of the entire United States. I am applying systematic literature review methods to search the OVID Medline database using specific keyword queries. A total of 1,830 results were retrieved for screening, which identified 213 articles meeting the inclusion and exclusion criteria. A standardized data extraction process that will describe study types, water sources investigated, and microbial contamination markers. For a second objective, I am using preexisting watershed microbial contamination data from Minnesota and land cover data to identify a correlation between surrounding land use and microbial contamination. The study will provide an update on the status of water quality research in Minnesota and provide a description of the correlation with external factors. Results can be used for further research on water contamination catalysts, help improve and monitor water quality strategies, and promote safer drinking and recreational water sources in Minnesota.