Traditional photovoltaic (PV) substrates are primarily based on crystals of inorganic compounds (e.g., silicon). The inorganic PV substrates have proven to be reliable and efficient and are used in a wide variety of applications from providing power to street signs to powering the International Space Station. Traditional, inorganic based solar cells, however, are relatively expensive to manufacture (although costs are declining) and have limitations in terms of their flexibility, i.e., they are rigid. Solar cells manufactured using OPV compounds are less expensive to produce and can be made on a flexible plastic sheet. They have not yet been found to be as efficient and robust as inorganic PVs, but these differences are being reduced every year. The efficiency of a solar cell becomes less important when one considers the cost of manufacturing and the versatility of having a flexible solar cell. The goal of this project is to use computational chemistry to identify new possible OPV substrates. DFT calculations will be carried out using Spartan and Gaussian computational packages locally and at the San Diego Supercomputer Center. The calculated HOMO-LUMO gaps will reveal which compounds are best suited to pursue for actual synthesis.

Ring-Opening Metathesis Polymerization (ROMP) is a fast reaction that frequently uses ruthenium-based catalysts to produce polymers from cyclic olefins. Ring strain relief is the reaction's driving force, so it performs best when monomer ring strain energy is high. Under living ROMP conditions, polymer chains grow at relatively the same rate with no termination or transfer. As a result, living ROMP typically yields narrow molecular weight distributions. One of its limitations, however, is the common use of norbornene, a high strain cyclic olefin. Norbornene works well with ROMP due to its structure, but reliance on norbornene-derived polymers limit the range of properties. For example, it is time consuming to make these polymers water soluble, therefore limiting their biological applications. From an environmental standpoint, their inability to degrade is also a cause for concern due to the plastic waste crisis that continues to have adverse effects on humans and Earth’s ecosystems. Here we synthesize anti- and syn-benzoldioxids as alternative monomers to norbornene. Due to their high strain energy, these monomers are promising candidates for living ROMP, and the polymers they form have the potential to be water soluble and readily depolymerized. Our experimental design focuses on the synthesis of syn-benzoldioxid from the starting material 1,4-cyclohexadiene, polymerization with Grubbs Third Generation Catalyst, modification, and lastly, depolymerization.

With antibiotic-resistant bacteria on the rise, it is crucial that new types of antibiotics become readily available and intensively studied; from both mechanistically and structurally. NIS synthetases are a family of proteins found in numerous pathogenic bacteria that are proving themselves to be valuable drug candidates through small-molecule inhibition. This protein class is linked to the bacterial virulence because NIS synthetases, in this case DesD from Streptomyces coelicolor, are enzymes that synthesize polyhyrdoxamate siderophores, which are dimeric or trimeric metabolites used by the bacterium to acquire iron from the environment then transport it into the cell as a vital nutrient. Our long term goal, using synthetic chemistry and enzymology, is to fully characterize the DesD active site so that small molecules can be designed to disrupt the absorption of iron they need for survival. We have two target substrates, ​​N1-hydroxy-N1-succinyl cadaverine (HSC) and succinyl cadaverine(SC). HSC has been prepared on the milligram scale via modification of a seven step literature synthesis involving three protecting groups; kinetic studies on DesD using isothermal titration calorimetry (ITC) were recently reported through a collaborative effort at CLU. A focus of the present work is multi-milligram synthesis of SC from N1-Boc cadaverine, N2-succinylation, and final deprotection of the N1 -Boc protecting group. Access to SC will allow for further knowledge of DesD macrolation bond formation in the absence of the N-Hydroxy functional group. In future studies, our synthetic route will be to prepare desferrioxamine D, (DfoD) to isolate the trimerization and macrocyclization.