Browsing by Author "Bromfield-Lee, Deborah C."
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ItemEngaging organic students in the message and limitation of models(ACS Publications, 2021) Bromfield-Lee, Deborah C.Chemistry courses are filled with models. Organic chemistry utilizes a wide variety of models from tangible model kits, to mechanisms, to computational analysis and spectral information. Often students are presented with these models without any discussion on their limitations or how various models allow us to derive information. Students can use molecular model kits to visualize stereoisomers and derive R/S, but a demonstration of doing this by the instructor can be very helpful. Aromaticity is displayed in many texts as a set of rules for students to memorize. While there are some models that help explain the rules and other models can display aromaticity, some of both types of these models have limitations. However, some of those models have limitations. Reactivity of carbonyls is also often relegated to a pattern or rules. Reactivity that is not explicitly discussed in lecture or the texts then may not be immediately obvious to students. Computational data, mechanisms, and model kits can help students understand the trends, but it is important for students to know how to use these, what the models indicate, and where they are derived. This chapter discusses how students are engaged in lecture with a few of these models to encourage critical thinking evaluating the models. This chapter includes examples of these classroom activities and reports both instructor and student evaluation of the usefulness and limitations of the models. ItemAn esterification kinetics experiment that relies on the sense of smell(Division of Chemical Education of the American Chemical Society, 2009-01) Bromfield-Lee, Deborah C.; Oliver-Hoyo, Maria T.This experiment involves an esterification synthesis to study reaction kinetics where students explore these topics utilizing the sense of smell rather than the traditional approach of using spectroscopic methods. Students study the effects of various factors including the concentration of the carboxylic acid and the amounts of the catalyst or alcohols added. The kinetics in relation to the molecular structure is studied by changing the chain lengths and branching of alcohols or the carboxylic acids and inferring the effects on rates of the reaction from the rates of ester detection. Since many esters have naturally occurring aromas that are pleasant and easily recognized, this experiment studies esterification kinetics using the sense of smell to detect the emergence of the ester aroma formed during the reaction. Feedback from students strongly suggests their interest in the experiment as they discovered that their sense of smell could be used as an analytical tool. ItemEvaluation of the Greener Synthesis of a Series of Electronically Modified Stilbene Analogues as Novel Anticancer Agents(Florida Southern College, 2021-05) Metcalfe, Candace Jessica; Bromfield-Lee, Deborah C.Cancer is the uncontrolled proliferation of abnormal cells that affects millions of people. Due to the important role microtubules play in cell division, drugs-targeting microtubules can initiate apoptosis, preventing further proliferation of cancer cells, and thus, are often used in chemotherapy. While extensive research has been done to develop anti-cancer drugs targeting taxanes and vinca alkaloid binding sites of microtubules, there are currently no Food and Drug Administration approved colchicine-binding site inhibitors (CBSIs) that have been approved for cancer treatment. Due to the preliminary promising results of CBSIs, a series of electronically varied stilbene analogues targeting the colchicine-binding site of microtubules was synthesized using green chemistry principles. The characterizations of the products via GC-MS and NMR indicated there was a disproportionately large amount of byproduct relative to the desired target compounds. Due to COVID-19 restrictions, solely computational docking studies were used to compare the effectiveness of the molecule with various electron donating and withdrawing groups (EDGs and EWGs) added to the stilbene scaffold at different positions and in different combinations. The docking poses suggest stilbene analogues may not bind to the colchicine domain, and the docking scores reflected more EWGs than EDGs had equivalent or higher binding affinities compared to past intended CBSIs, but were not statistically significant. Further studies need to be conducted to assess actual binding and cytotoxicity. ItemImplementation and student perceptions on Google Docs as an electronic laboratory notebook in organic chemistry(American Chemical Society, 2018-05-30) Bromfield-Lee, Deborah C.Electronic laboratory notebooks are gaining in popularity in industry and academia. Various types of electronic laboratory notebooks exist, and a variety of tools can be used for these forms of notebooks. Some tools are commercial products dedicated to being electronic notebooks, while individual organizations can develop ones for their own needs with tools such a OneNote and Google Docs. Google Docs was used as an electronic notebook in organic chemistry, and student perceptions were evaluated using surveys. These tools are used to reduce students’ time preparing for lab and writing reports. The implementation of the notebooks and the findings of students’ perceptions on the implementation are discussed. ItemA qualitative organic analysis that exploits the senses of smell, touch, and sound(Division of Chemical Education of the American Chemical Society, 2007-12) Bromfield-Lee, Deborah C.; Oliver-Hoyo, Maria T.This laboratory experiment utilizes the characteristic aromas of some functional groups to exploit the sense of smell as a discriminating tool in an organic qualitative analysis scheme. Students differentiate a variety of compounds by their aromas and based on their olfactory classification identify an unknown functional group. Students then perform chemical tests that rely on the senses of touch, smell, and sound to confirm the functional group present. The use of a light probe enables students to qualitatively analyze many visual changes as an auditory response. Students "hear" significant changes in color, solution viscosity, and the presence of a precipitate. Students group compounds by their functional group characteristic smells, decide on necessary confirmatory tests based on their own classification, and utilize effectively the senses of touch, sound, and smell to identify their unknowns. Student feedback strongly stated they enjoyed the experiment particularly discovering the characteristics of each functional group physically and chemically. Based on the write-ups and performance of the students in the laboratory, it is evident that this sensorial laboratory can add richness to traditional organic laboratories. ItemRe-casting traditional organic experiments into green guided-inquiry based experiments: student perceptions(Taylor and Francis, 2019-06) Bromfield-Lee, Deborah C.Green Chemistry principles can be used to re-cast traditional Organic chemistry experiments into more guided-inquiry based experiments. Inquiry questions related to green chemistry principles and metrics have been incorporated into our laboratory for the development of more guided-inquiry based experiments. Re-casting traditional experiments provides time for guided-inquiry by allowing students to evaluate reaction conditions and wastefulness of reactions. This includes evaluating solvent choices, heating methods, use of renewal materials, and contemplating reactants and products impacts on human health and environment. Students examine the changes as it pertains to green chemistry, the success of the reaction and the potential impacts on the mechanism. Involving students in these discoveries rooted in a guiding question made the Organic experiments guided-inquiry. Students were surveyed about their exposure to green chemistry and guided-inquiry based labs. Examples of some of the re-casted experiments, excerpts from student reports, and student impressions of the theme are presented. ItemTactile models for the visualization, conceptualization, and review of intermolecular forces in the college chemistry classroom(American Chemical Society and Division of Chemical Education, 2021-04) Bromfield-Lee, Deborah C.; Beggs, Grace A.The authors describe the construction and use of tactile models for demonstrating intermolecular forces. These models are composed of inexpensive materials and can be used in college chemistry classrooms of varying levels including general and organic chemistry. The models were designed to be paired with an accompanying activity to encourage students to compare and contrast the three types of intermolecular forces (hydrogen bonding, dipole-dipole forces, and London dispersion forces) as well as determine the relationship between intermolecular forces and the physical properties of specific molecules. More importantly, the handheld models allow for visualization of molecular interactions to promote multisensory learning. In this work, the authors discuss the development, implementation, and survey results of a modeling activity for conceptualization and review of intermolecular forces in introductory, general, and organic chemistry classrooms. ItemUsing laboratory chemicals to imitate illicit drugs in a forensic chemistry activity(Division of Chemical Education of the American Chemical Society, 2008-06) Hasan, Shawn; Bromfield-Lee, Deborah C.; Oliver-Hoyo, Maria T.; Cintron-Moldonado, Jose A.This forensic chemistry activity utilizes presumptive forensic testing procedures and laboratory chemicals that produce screening results similar to controlled substances. For obvious reasons, obtaining heavily regulated controlled substances to create an undergraduate student activity is not practical for most educational institutions. We were able to identify over-the-counter and laboratory chemicals that mimic actual street drugs in terms of physical properties and color response. Using these selected chemicals, the screening aspect of drug testing provides students with the opportunity to understand what obstacles a forensic chemist faces when analyzing a sample of unknown identity. Chemical spot tests (CSTs) and thin-layer chromatography (TLC) were chosen owing to their simplicity, versatility, common use by forensic chemists, availability, and cost of the reagents and equipment needed. Students are expected to explain how simple color reactions can screen for illicit drugs, to describe how TLC can be used to separate and tentatively identify drugs, to predict how polarity changes affect TLC results, and to explain why CSTs and TLC serve for screening purposes only.