Reasoning about structure, reactivity, and chemical processes is a critical competency for organic chemistry students. Yet many students cannot fully interpret or explain the underlying chemical reasoning behind the many representations we use to depict chemical phenomena. We need to know more about how to scaffold students reasoning as they learn to translate and make meaning of the symbols and language of organic chemistry.

The first part of the talk describes experimental studies of molecular-weight growth pathways leading to PAH formation under combustion conditions, focusing on resonantly stabilized radicals, strained aromatic intermediates, and radical–radical chain-propagating (“well-skipping”) chemistry. Three complementary studies highlight the importance of five-membered-ring motifs in curved aromatic growth.

Atmospheric pollutants, ranging from traditional organic aerosols to emerging contaminants such as nanoplastics and per- and polyfluoroalkyl substances (PFAS), play critical roles in air quality, climate forcing, and environmental health. Yet their sources, atmospheric transformations, transport pathways, and impacts remain poorly constrained.

Cycloaddition reactions have been recognized as a robust method to construct carbocyclic or heterocyclic systems in a highly convergent manner through a concerted or stepwise mechanism since the original discovery of the Diels-Alder reaction. N-Heterocyclic compounds are considered “privileged structures” in pharmaceutical and medicinal chemistry for their core structure being present in many biologically active molecules and building blocks.

This talk will follow one major track through my research over the past half century. It starts with how soot forms in fuel rich flames and the resultant fractal morphology. This fractal nature is universal to all aggregating systems of solid particles and, as I will explain, can ultimately lead to gelation. Experiments to create aerosol gels in closed chambers led to the chance discovery of a viable method to make multi-layer graphene of commercial value.

Lipids are vital for cellular functions, acting as structural components, signaling molecules, and energy sources. Their metabolism, particularly through cytochrome P450s and other oxidizing enzymes, plays a key role in inflammation and disease. This study uses biochemical, analytical, and biophysical methods to examine the metabolism of endocannabinoids (a class of signaling lipids) and minor cannabinoids by membrane-bound cytochrome P450s, stabilized in nanoscale lipid bilayers (Nanodiscs).

Four graduate students from the Department of Chemistry were recently named as recipients of graduate fellowships for students who are specializing in cancer research. Jiayi Wang and Yi Tang of the Xie research group and Takbir Hossain of the Phillips research group were awarded the Grimes Family Distinguished Graduate Fellowship in Natural Sciences, which provides academic year support to a graduate student in Franklin College majoring in the Natural Sciences working on the area of cancer research.

The overarching theme of our research program concerns the development of new and general pericyclic strategies that enable efficient access to complex cyclic frameworks of biological importance. A hallmark of our approach is the design of atypical cycloaddition reaction partners that are at a high oxidation level (i.e., large degree of heteroatom incorporation and/or unsaturation) in order to confer unique reactivity, while also minimizing the need for redox manipulations post cycloaddition.