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General chemistry laboratories are a core requirement for nearly all STEM (Science, Technology, Engineering, and Mathematics) majors and have the greatest breadth in disciplines and audience of any STEM course at a university. A bioremediation Course-based Undergraduate Research Experience (CURE) for first-year undergraduate students was developed to capture and engage student interest for this diverse group. In this multiweek laboratory exercise, students joined an NSF-funded research project designed to enhance the bioremediation of chlorinated aliphatic hydrocarbons. Students explored various biocompatible polymer blends and cross-linkers for encapsulation to create protection for bioremediation microbes. In this “guided research” model, students constructed the measurement apparatus, made hydrogel blends, and then monitored the diffusion of acid via pH measurements using a custom instrument. Herein, we describe how CURE elements were implemented within the bioremediation research experience culminating in student teams presenting posters at our university’s undergraduate research symposium. An open-laboratory format facilitated an active research group experience and recitation “group meeting” provided flexibility and needed time for reflection and discussion. Student survey data and course evaluations indicated that students saw value in this genuine research experience and enjoyed the freedom and time to practice and hone skills as both a scientist and teammate in a laboratory setting.

Polyampholyte hydrogels are attractive materials for tissue engineering scaffolds as they offer a wide variety of features including nonfouling, selective protein delivery, and tunable physical characteristics. However, to improve the potential performance of these materials for in vivoapplications, there is a need for a higher diversity of zwitterionic cross-linker species to replace commonly used ethylene glycol (EG) based chemistries. Towards this end, the synthesis of a dipeptide based zwitterionic cross-linker, N-Ser–Ser-C dimethacrylate (S–S) from N-Boc-l-serine is presented. The strategy utilized a convergent coupling of methacrylated serine partners followed by careful global deprotection to yield the zwitterionic cross-linker with good overall yields. This novel cross-linker was incorporated into a polyampholyte hydrogel and its physical properties and biocompatibility were compared against a polyampholyte hydrogel synthesized with an EG-based cross-linker. The S–S cross-linked hydrogel demonstrated excellent nonfouling performance, while promoting enhanced cellular adhesion to fibrinogen delivered from the hydrogel. Therefore, the results suggest that the S–S cross-linker will demonstrate superior future performance for in vivoapplications.

Carbohydrates are an essential group of molecules to the organic chemistry classroom providing molecular relevance to a common ingredient in chemical biology. While the meticulous elucidation of the carbohydrate structures by Fischer and others is an engaging topic in the lecture, there are few laboratory experiments that can emulate carbohydrate complexity. Advanced and multidimensional NMR (2D NMR) techniques such as correlation spectroscopies (COrrelation SpectroscopY (COSY), 13C Distortionless Enhancement by Polarization Transfer (DEPT), and HETeronuclear CORrelation (HETCOR) or Heteronuclear Single Quantum Coherence (HSQC)) have become more routine as they require less time on today’s instruments and are taught more often in lecture. A laboratory experiment is described for second-year introductory undergraduate organic chemistry students that involves the transformation of nutraceutical N-acetyl-d-glucosamine to α-chloroglucosamine tetraacetate. After synthesis and simple workup, students collect four different NMR spectra from which they identify each 1H signal in the product. Students learn to identify each signal’s multiplicity and how multiple NMR experiments are used to characterize a product. Student confidence in NMR characterization was assessed on a small subset through postlab questions and pre- and postsurvey data.

Redox-active azothioformamide (ATF) ligands produce coordination complexes with Cu(I) salts. A series of monosubstituted ligands were used to synthesize Cu(I) complexes and investigated for the catalytic insertion of carbon dioxide into terminal alkynes. The optimal catalytic conditions were found using phenylacetylene with 4 mol % of a halogen-bridged (μ-I)-para-substituted [(p-MeOATF-Cu(I)I)]2dimer with 3 equiv of Cs2CO3as the base in dimethyl sulfoxide under 1 atm of CO2at 40 °C for 24 h, followed by treatment with HCl. A variety of aryl and alkyl substrates were evaluated giving yields from 47 to 99%. The reaction was computationally deconstructed, and a series of likely intermediates and associated energies are provided along with a proposed mechanism. Additionally, it was found that the conditions were suitable for one-pot esterification.

We present a facile microfluidic method for forming narrow chemical gradients in polymer brushes. Co-flow of an alkylating agent solution and a neat solvent in a microfluidic channel forms a diffusion-driven concentration gradient, and thus a gradient in reaction rate at the interface of the two flows, leading to a quaternization gradient in the underlying poly(2-(dimethylamino)ethyl methacrylate) polymer brush. The spatial distribution of the quaternized polymer brush is characterized by confocal Raman microscopy. The quaternization gradient length in the polymer brush can be varied with the injection flow rate and the distance from the co-flow junction. A chemical gradient in the polymer brush as narrow as 5 μm was created by controlling these parameters. The chemical gradient by laminar co-flow is compared with numerical calculations that include only one adjustable parameter: the reaction rate constant of the polymer brush quaternization. The calculated chemical gradient agrees with the experimental data, which validates the numerical procedures established in this study. Flow of multiple laminar streams of reactive agent solutions enables single-run fabrication of brush gradients with more than one chemical property. As one example, four laminar streamsneat solvent/benzyl bromide solution/propargyl bromide solution/neat solventgenerate multistep gradients of aromatic and alkyne groups. Because the alkyne functional group is a click-reaction available site, the alkyne gradient could allow small gradient formation with a wide variety of chemical properties in a polymer brush.

A required first-year laboratory course was overhauled into a semester-long biosciences course-based undergraduate research experience (BioCURE) with a goal of enhancing learning and improving retention. Student attributes and outcomes were continually monitored by the University’s Institutional Research office over a 5-year period and compared against the pre-BioCURE (traditional Biology lab course). Success in the BioCURE was found to be correlated with a passing grade (ABC) in prerequisite majors’ chemistry as opposed to nonmajors’ chemistry; concurrent enrollment in either majors’ or nonmajors’ chemistry was less effective than prerequisite majors’ chemistry. This unique metric, of assessing the value of a chemistry course as seen through the success in a subsequent bioscience course, provides the authors with convincing evidence to encourage educators to focus on a rigorous, early academic chemistry foundation as well as emphasize interconnections with other disciplines. Diving deeper, success in a more challenging chemistry course prior to taking a required biology course during biological science students’ first two collegiate years correlated with increases in student success in biological sciences degree plans, as evidenced by subsequent increases in retention into the third year and six year graduation rates. Students with ABC grades in any first-year chemistry course had a higher rate of graduating in an initially chosen bioscience discipline, but majors’ chemistry benefited at-risk students disproportionately more than high-GPA students showing that early chemistry success is critical for strengthening a diverse STEM workforce.

The open‐chain Fischer carbenes (II) are suitable substrates for the construction of various title compounds where the seven‐membered ring and one of the benzene rings are formed in a single step.