Creating a diverse array of structurally distinct, triazine-containing, macrocycles remain the focus of the Simanek group. Until now, this goal has been accomplished through a straightforward 3 step synthetic route with variation of amino acid incorporation and acetal length. Currently two new approaches to macrocycle synthesis are being pursued. The first approach relies on two like monomers coming together: by changing the relative position of groups in the macrocycle, the persistence of shape can be probed. The second approach relies on two different monomers coming together. Using a similar synthetic route, this strategy, if successful, will allow much finer control over design and engineering these molecules for specific purposes. These libraries of structurally diverse macrocycles are important for the long-term goals of establishing rules that can guide pharmaceutical drug design in these under-explored types of molecules.

EUK-134 is a manganese-salen complex widely used in anti-aging skincare formulations due to its potent antioxidant activity resulting from catalytic decomposition of reactive oxygen species. Despite its popularity, the fundamental kinetic properties that govern its efficacy and recyclability are not well understood, limiting its optimization in skincare products. As a result, the study presented here investigates the efficiency, sustained activity, and selectivity of EUK-134 in comparison to the Green lab ligand library by evaluating its turnover number (TON), turnover frequency (TOF), and reaction rate. Results indicate that while EUK-134 demonstrates high catalase-type activity and selectivity, the activity decreases with continuous exposure to H₂O₂, suggesting a need for re-application in real-world scenarios to achieve long-term protection. Additionally, selectivity studies show that peroxidase activity was observed, which may impact the stability of sensitive ingredients in formulations. These findings provide essential kinetic benchmarks to compare future small molecules and optimize EUK-134’s use in antioxidant skincare products. Without a clear understanding of these fundamental properties, we lack benchmarks to compare future small molecules that compete with EUK-134.

Metal-halide perovskites are crystalline materials that work as a semiconductor in both Light Emitting Diodes (LEDs) and solar cells. In general, perovskites possess the formula ABX3. For this project, the A site is an organic molecule such as Methylammonium (MA), the B site is Lead, and the X site is Bromide. While perovskites are easily fabricated, their crystal size and number of defects present are challenging to control. Defects cause LEDs to be less stable and/or less photoluminescent (bright) and cause solar cells to be less efficient at converting light to energy. One approach to reduce the number of defects is to use ionic liquids during perovskite formation. Ionic liquids are compounds made of ions in the liquid state due to a low melting temperature. They can be added to the perovskite precursor solution to slow down the crystallization process so that fewer defects are created. The goal of this project is to create new metal halide perovskites in the presence of selected ionic liquids, evaluate their structure and photophysical properties, with the long-term goal of creating new LEDs that are both stable and efficient.

In this project, cetyl-ionic liquids (cetyl meaning 16 carbon chains) were investigated for their effects on perovskite structure and light emission. The three ionic liquids were investigated: [C16-mim]Br (referred to as "IL1"), [C16-py]Br ("IL2"), [C16-C1pyrr]Br ("IL3"), and CTAB (“IL4”). Variations in the deposition method of the perovskite films were studied as well. It was hypothesized that the inclusion of cetyl-ionic liquids will protect the perovskite films from the environment (increasing stability) by providing a hydrophobic layer on the surface and will improve the electronic properties by filling in pinholes that cause defects. It is found that perovskite films with IL1 produced through a two-step spin coat deposition method are more photoluminescent than the perovskite films formed with IL2, IL3, IL4 or no IL (control). These results, along with detailed structural characterization of a given perovskite film, will be discussed in this presentation.

Hinges are pervasive in the world today. Most common is a simple mortise door hinge  - defined by the flush stacking of leaves and fully revolute motion. Chemists have long sought to reproduce such structures on the molecular scale. Here, the hinge behavior of large, cyclic molecules is described.  Moreover, hinge motion can be controlled by "gumming up" the parts responsible for motion. While dirt and debris work in the macroscopic world, additional atoms are used in these molecular mimics. Specifically, by increasing the size of groups in the hinge domain, the rate of hinging decreases. Hinge motion is visualized by variable temperature NMR spectroscopy where in, at low temperatures the hinging both faces of the leaves (inside and outside) can be observed. At high temperatures, the hinging speeds up and the inside and outside exchange too quickly to be observed. Unlike hinges of everyday use that require human assembly, the molecular hinges described here assemble themselves. As a result, hinges with identical leaves as well as hinges with mismatched leaves can be prepared. Surprisingly, the results of this assembly process are biased: a statistical distribution of hinges is not observed.  Further studies to understanding this steric (gumming) sorting are ongoing.

Platinum nanocrystals on Silicon nanotubes (PtNCs-pSiNT) exhibit significant anticancer activity via an apoptotic mechanism. To enhance the specificity of this material, we attach folic acid (FA) to the nanotube surface to target folate receptors (FARs) overexpressed in cancer cells. This conjugation is successfully demonstrated through X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FT IR). Cell viability assays show an enhanced cytotoxicity toward HeLa cells relative to its non-FA containing analog.

Platinum-based therapeutics, exemplified by the FDA-approved anti-cancer drug cisplatin, are a mainstay in treatment of a range of different cancer types.3 Although this drug can form an adduct with DNA and induce apoptosis, many studies have confirmed that cancer cells can develop resistance to this treatment. Alternatively, small Pt nanocrystals (Pt NCs) have demonstrated arrested growth and apoptosis in cancer cells as a consequence of DNA platination and enhanced strand-breaks initiated by leaching Pt(II) ions from the NC surface in the acidic intracellular environment. Small Pt nanocrystals whose size is less than 3 nm demonstrate a higher reduction in cell viability than those with larger size, presumably owing to a relatively greater exposed surface area for dissolution. This observation, coupled with the identification of downregulation of multiple genes critical for cancer cell proliferation after treatment with Pt NCs, has led to an observed reduction in addressing drug resistance. Such nanocrystals tend to aggregate extensively in an aqueous environment, however, and we have developed well-defined Silicon nanotubes (pSiNTs) as a scaffold for effective nanocarrier for drug delivery of such PtNCs, taking advantage of nanotube high surface area, biocompatibility, and biodegradability. Functionalization with 3-(aminopropyl)triethoxysilane (APTES), followed by incubation with dilute K2PtCl4 solution results in the formation of PtNCs-pSiNTs well dispersed on the pSiNTs to avoid aggregation and release the platinum as the pSiNTs are resorbed over time, which results in significant cancer cell cytotoxicity-ty. To enhance the specificity of this material we conjugate Folic Acid (FA) to the Pt surface using as a Glutathione (GSH) linker, with the goal of enhanced targeting of overexpressed FARs and more selective cancer cell uptake.