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1. Analytical chemistry students’ explanatory statements in the context of their corresponding lecture

   https://doi.org/10.1039/d0rp00063a  

   Wang, Ying; Lewis, Scott E. (September 2020, Chemistry Education Research and Practice)

   null (Ed.)

   Conceptually understanding chemistry requires the ability to transition among representational levels to use an understanding of submicroscopic entities and properties to explain macroscopic phenomena. Past literature describes student struggles with these transitions but provides limited information about upper-level post-secondary chemistry students’ abilities to transition among levels. This group is of particular interest as they are engaging in potentially their final training before entering a career as professional chemists, thus if students are likely to develop this skill during their formal education it should be manifest among this group. This study characterized analytical chemistry students’ responses to open-ended assessments on acid–base titrations and thin-layer chromatography for the use of sub-microscopic entities or properties to explain these macroscopic phenomena. Further, to understand whether explanatory statements were an expectation inherent in the instructional context of the setting, the analytical chemistry instructor's lectures on acid–base titrations and thin-layer chromatography were analyzed with the same framework. The analysis found that students seldom invoked explanatory statements within their responses and that congruence between lectures and responses to assessment was primarily limited to the use of macroscopic, descriptive terms. Despite the fact that the lecture in class regularly invoked explanatory statements in one context, this did not translate to student use of explanatory statements. To further test the hypothesis that analytical chemistry students struggle with explanatory statements, a follow-on study was also conducted among a second cohort of students reviewing their responses when specifically prompted to use sub-microscopic entities to explain a macroscopic phenomenon. The results suggest that fewer than half of the students showed proficiency on generating explanatory statements when explicitly prompted to do so. Instructional implications to promote explanatory statements are proposed in the discussion. 

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2. Cavity frequency-dependent theory for vibrational polariton chemistry

   https://doi.org/10.1038/s41467-021-21610-9  

   Li, Xinyang; Mandal, Arkajit; Huo, Pengfei (February 2021, Nature Communications)

   Abstract Recent experiments demonstrate the control of chemical reactivities by coupling molecules inside an optical microcavity. In contrast, transition state theory predicts no change of the reaction barrier height during this process. Here, we present a theoretical explanation of the cavity modification of the ground state reactivity in the vibrational strong coupling (VSC) regime in polariton chemistry. Our theoretical results suggest that the VSC kinetics modification is originated from the non-Markovian dynamics of the cavity radiation mode that couples to the molecule, leading to the dynamical caging effect of the reaction coordinate and the suppression of reaction rate constant for a specific range of photon frequency close to the barrier frequency. We use a simple analytical non-Markovian rate theory to describe a single molecular system coupled to a cavity mode. We demonstrate the accuracy of the rate theory by performing direct numerical calculations of the transmission coefficients with the same model of the molecule-cavity hybrid system. Our simulations and analytical theory provide a plausible explanation of the photon frequency dependent modification of the chemical reactivities in the VSC polariton chemistry. 

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3. Secret messaging with endogenous chemistry

   https://doi.org/10.1038/s41598-021-92987-2  

   Kennedy, Eamonn; Geiser, Joseph; Arcadia, Christopher E.; Weber, Peter M.; Rose, Christopher; Rubenstein, Brenda M.; Rosenstein, Jacob K. (December 2021, Scientific Reports)

   null (Ed.)

   Abstract Data encoded in molecules offers opportunities for secret messaging and extreme information density. Here, we explore how the same chemical and physical dimensions used to encode molecular information can expose molecular messages to detection and manipulation. To address these vulnerabilities, we write data using an object’s pre-existing surface chemistry in ways that are indistinguishable from the original substrate. While it is simple to embed chemical information onto common objects (covers) using routine steganographic permutation, chemically embedded covers are found to be resistant to detection by sophisticated analytical tools. Using Turbo codes for efficient digital error correction, we demonstrate recovery of secret keys hidden in the pre-existing chemistry of American one dollar bills. These demonstrations highlight ways to improve security in other molecular domains, and show how the chemical fingerprints of common objects can be harnessed for data storage and communication. 

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4. Integrating Machine Learning and Color Chemistry: Developing a High-School Curriculum toward Real-World Problem-Solving

   https://doi.org/10.1021/acs.jchemed.3c00589  

   Jiang, Shiyan; McClure, Jeanne; Mao, Hongjing; Chen, Jiahui; Liu, Yunshu; Zhang, Yang (December 2023, Journal of Chemical Education)

   Artificial intelligence (AI) is rapidly transforming our world, making it imperative to educate the next generation about both the potential benefits and the challenges associated with AI. This study presents a cross-disciplinary curriculum that connects AI and chemistry disciplines in the high school classroom. Particularly, we leverage machine learning (ML), an important and simple application of AI to instruct students to build an ML-based virtual pH meter for high-precision pH read-outs. We used a “codeless” and free ML neural network building software, Orange, along with a simple chemical topic of pH to show the connection between AI and chemistry for high-schoolers who might have rudimentary backgrounds in both disciplines. The goal of this curriculum is to promote student interest and drive in the analytical chemistry domain and offer insights into how the interconnection between chemistry and ML can benefit high-school students in science learning. The activity involves students using pH strips to measure the pH of various solutions with local relevancy and then building an ML neural network model to predict the pH value based on the color changes of pH strips. The integrated curriculum increased student interest in chemistry and ML and demonstrated the relevance of science to students’ daily lives and global issues. This approach is transformative in developing a broad spectrum of integration topics between chemistry and ML and understanding their global impacts. 

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5. Speaking to Learn and Learning to Speak: Service-Learning Involving Communication in the Chemistry Curriculum

   https://doi.org/10.1021/acs.jchemed.2c00985  

   Bowe, Kathleen A.; Green, Alexa R.; Gorske, Yi Jin; Lesher, Emily; Bauer, Christopher F. (August 2023, Journal of Chemical Education)

   Community-based learning (CBL), also known as service learning (SL), provides students with an active and meaningful learning environment and has been studied in STEM courses for several decades. Chemistry for the Community is a novel chemistry curriculum that weaves service-learning projects throughout multiple courses, including gateway courses, and allows students to build self-efficacy and transferable skills. Over a three-year period, students experienced multiple projects while enrolled in two-semester general and organic chemistry courses, and one-semester organic survey, environmental, and analytical chemistry courses. Student experiences, gathered by surveys, reflections, and interviews were compared to those of students conducting equivalent non-SL projects, as well as projects conducted virtually due to the COVID-19 pandemic. Public communication and community partner interaction emerged as major themes from the data and were explored through the lens of self-determination theory. Results indicate that students were anxious about their role, but were motivated by community partner interaction. Project completion corresponded to an increase in self-efficacy regarding similar future tasks, with students perceiving benefits of multiple experiences. 

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