Organic Chemistry Laboratory Course Research Articles

Reaction Optimization Experiment for Undergraduate Capstone Organic Chemistry Laboratory Course

Reaction Optimization Experiment for Undergraduate Capstone Organic Chemistry Laboratory Course

Virtual Reality in an Eco-Niche Undergraduate Organic Chemistry Laboratory Course: New Practice in Chemistry Lab Teaching

Virtual Reality in an Eco-Niche Undergraduate Organic Chemistry Laboratory Course: New Practice in Chemistry Lab Teaching

Leveraging undergraduate learning assistants when implementing new laboratory curricula

At University of California, Irvine, a large-enrollment research university, undergraduate chemistry courses for non-chemistry majors were delivered remotely during the 2020–2021 academic year, with a return to in-person instruction planned for January 2022. Because this return to in-person instruction coincided with the transition of second-year students from general chemistry to organic chemistry laboratory courses, the instructional staff recognized a need for remedial laboratory curricula for students with no prior in-person laboratory experience. Simultaneously, we desired to implement undergraduate Learning Assistants (LAs) in non-chemistry major organic chemistry laboratories for the first time at our university. In this paper, we describe our approach for leveraging undergraduate LAs to (1) test new laboratory curricula and (2) address feelings of comfort and safety for students with no prior in-person laboratory experience. Benefits of our LA program perceived by students include increased laboratory efficiency and improved student learning from near-peer instructors; benefits perceived by LAs include the development of professional skills and teamwork with graduate student teaching assistants. We provide an outline of resources and strategies to enable instructors to simultaneously implement undergraduate LAs and new laboratory curricula.

The evolution of an assignment: how a Writing-to-Learn assignment's design shapes organic chemistry students’ elaborations on reaction mechanisms

Asking students to explain why phenomena occur at a molecular level is vital to increasing their understanding of chemistry concepts. One way to elicit students’ mechanistic reasoning and guide construction of knowledge is through Writing-to-Learn (WTL), which is a promising approach for students in organic chemistry courses. In the design of WTL assignments, rhetorical aspects provide an authentic context by designating a role, genre, and audience for students. This context can support students’ learning, but, if the rhetorical aspects misalign with the learning objectives of the assignment, they can hinder students’ ability to achieve these objectives. In this project, we designed a WTL assignment about a base-free Wittig reaction, which we implemented in an organic chemistry laboratory course. Here, we explore how changes in the rhetorical aspects of this assignment can influence the way students explain two different comparisons of reaction mechanisms. We consider how students use explicit and implicit properties and how the use of these features compares within the context of the reaction. Results indicate that, when the rhetorical aspects align with the learning objectives of the assignment, students provide more productive elaborations that use both explicit and implicit properties. This is supported by both the analysis of students’ writing and students’ feedback about the assignments.

A Comprehensive Inquiry-Based Comparative Experiment for an Undergraduate Organic Chemistry Laboratory Course: Elucidating the Formation Process of N-Phenylbenzamide

A Comprehensive Inquiry-Based Comparative Experiment for an Undergraduate Organic Chemistry Laboratory Course: Elucidating the Formation Process of <i>N</i>-Phenylbenzamide

Copper(I)-Catalyzed Kinugasa Reactions in an Undergraduate Organic Chemistry Laboratory

A β-lactam, the core structure unit of clinically important antibiotics such as penicillin and cephalosporin, is one of the most commonly encountered four-membered heterocycles in organic chemistry and is widely used in medicine and biochemistry. The Kinugasa reaction, a copper(I)-catalyzed cycloaddition of a terminal alkyne with a nitrone, is a straightforward and atom economic approach to 2,3-disubstituted β-lactams. This paper describes a comprehensive chemistry experiment involving the Kinugasa reaction in an advanced undergraduate organic chemistry laboratory course. Undergraduate students perform the Kinugasa reaction on the benchtop and isolate and characterize the β-lactam product. An understanding of this named reaction and the connection of organic chemistry with medicinal chemistry are specially emphasized in the class. Several modern chemistry concepts that are missing from traditional organic courses such as β-lactam chemistry, [3 + 2] cycloaddition, atom economy, and the important role of transition metal catalysis in organic reactions are introduced to students in this course.

Show Me You Can Do It: Practical Examinations for Senior Organic Chemistry Laboratory Courses

Written examinations for laboratory courses fall short in testing students’ technical skills, problem-solving abilities, and execution of experimental design. This has led to practical examinations growing in popularity, but examples for senior-level students remain scarce. Senior organic chemistry students are gearing toward independence to design and execute their own experimental procedures. Thus, an examination reflective of key aspects of an experimental procedure is suitable for such students. The key stages identified in most organic reaction processes are as follows: the design and assembly of the experiment, the execution of the reaction, the workup, the purification, and data analysis of the isolated product(s). Time constraints in an examination make implementing all these stages generally unfeasible. Herein are presented two different practical examinations for third and fourth year level students in an organic chemistry laboratory. To ensure students had adequate time to complete the exam, some stages of the organic reaction process were removed (e.g., the reaction execution), or partially removed, with a focus on the key learning outcomes of the lab course. In addition, a comparison of the course and exam averages is included to illustrate alignment between students understanding throughout the term as compared to the final exam. Finally, a summary of student perceptions of the exams via survey data collected from students is also incorporated. Student’s perceptions are compared to observations made by the instructor and teaching assistants.

Calculating the Enthalpy of Vaporization of Ethanol, n-Heptane, Isooctane, and a Binary Mixture of Isooctane + n-Heptane from Their Vapor Pressure Data

ConspectusA key physical property of volatile liquids is vapor pressure (VP). Volatile organic compounds (VOCs) are a classification of compounds directly associated with low boiling points, high rates of evaporation, and high flammability. The majority of chemists and chemical engineers were directly exposed to the odor of simple ethers, acetone, and toluene in the air while taking an organic chemistry laboratory course as an undergraduate student. These are just a few examples of the numerous VOCs produced by the chemical industry. When toluene is poured into a beaker from its reagent bottle, its vapors readily evaporate at ambient temperature from this open container. When the cap is securely placed back on the reagent bottle of toluene, a dynamic equilibrium develops and exists in this closed environment. This chemical concept is known as a vapor-liquid phase equilibrium. A crucial physical property of spark-ignition (SI) fuels is high volatility. In the United States, most of the vehicles traveling on the road today have SI engines. Gasoline is the fuel used to power these engines. It is a major product manufactured by the petroleum industry. This fuel is petroleum based since it is a refined product of crude oil consisting of a mixture of hydrocarbons, additives, and blending agents. Thus, gasoline is homogeneous solution of VOCs.The VP as a function of temperature of a pure VOC can readily be measured using an ebulliometer. The VP is also known in the literature as the "bubble point pressure". In this investigation, the VP as a function of temperature was acquired for the VOCs ethanol, isooctane (2,2,4-trimethylpentane), and n-heptane. The latter two VOCs are primary reference fuels components found in 87, 89, and 92 grade gasoline. Ethanol is an oxygenate additive of gasoline. The VP of a homogeneous binary mixture of isooctane and n-heptane was also acquired using the same ebulliometer and methodology. In our work, an enhanced ebulliometer was used to collect the VP data in our work. It is known as the vapor pressure acquisition system. The devices that comprise the system automatically acquire the VP data and log it into an excel spreadsheet. The data are readily transformed into information to compute the heat of vaporization (ΔHvap). The results described in this Account compare quite favorably to the literature values. This validates our system for performing fast and reliable VP measurements.

A Thin Layer Chromatography Prelaboratory Activity Using a 3D-Printed Model to Address Student Misconceptions about Polarity and Intermolecular Forces

Normal phase thin layer chromatography is a widely taught technique in undergraduate organic chemistry laboratory courses. To understand how the technique works, students must have a strong conceptual understanding of polarity and intermolecular forces. Unfortunately, many students have misconceptions regarding how polarity and intermolecular forces affect the separation of compounds via thin layer chromatography. This work aimed to address these misconceptions by designing and implementing a prelaboratory activity using a 3D-printed model of a TLC plate. Data from pre- and postactivity surveys suggest the activity has a positive impact on student understanding, and student perceptions of the activity are overwhelmingly positive.

Do-It-Yourself 5-Color 3D Printing of Molecular Orbitals and Electron Density Surfaces

This report outlines an approach for preparing 5-color 3D printed plastic models of molecular orbitals and electron density surfaces using a hobby-grade 3D printer. Instructions are provided for preparing 3D orbital and electron density surface (EDS) models using solid or mesh representations in ground state and transition state structures. We show that the information content of 3D orbital and surface models can be enhanced with text annotation, bisection, strut and dashed bond placement, and composite orbital-EDS model constructions. Example prints illustrate orbital concepts in organic and inorganic chemistry, such as the ethyl cation (σ–p hyperconjugation), methane (hybridization and C–H bonding), ethane (σ–σ* hyperconjugation in the staggered and eclipsed conformations), 2-hydroxytetrahydropyran (the anomeric effect/n−σ* hyperconjugation), the water dimer (hydrogen bonding/n−σ* overlap), ethylene, 1,3-butadiene, and benzene (π molecular orbitals), Re2Cl82–, and U2(COT)2 (metal–metal quadruple bonds). Transition state models illustrate orbital interactions in the SN2 reaction of cyanide with methyl, ethyl, and isopropyl chloride and in a hydroboration reaction of BH3 with propene. Composite EDS models of methyl and isopropyl chloride (for exploring their relative reactivities as SN2 electrophiles) and methylcyclohexane (visualizing 1,3-diaxial interactions) are described. Student perceptions of a multicolor 3D orbital print used in an introductory organic chemistry laboratory course are reported.

Exploration and Practice on Improving the Teaching Quality of Organic Chemistry Laboratory Course

Exploration and Practice on Improving the Teaching Quality of Organic Chemistry Laboratory Course

Inter-Twine-d: Combining Organic Chemistry Laboratory and Choose-Your-Own-Adventure Games

Remote delivery approaches to laboratory courses in the response to the COVID-19 pandemic have included a spectrum spanning passive options such as providing students with prerecorded videos of experiments to replacing in-person laboratory experiences with immersive virtual reality environments. While interactive activities that require students to make choices about experimental design or procedure, mimicking levels of inquiry present in in-person laboratory experiments, are preferred, creating custom activities of this type often require expensive equipment, a media production team, and knowledge of multiple programming languages. The open source, nonlinear storytelling platform, Twine, provides a free alternative that allows instructors to create custom interactive choose-your-own-adventure activities based on their existing laboratory curriculum and inclusive of text, images, and video clips. We used Twine to create a choose-your-own-adventure laboratory activity as the final experiment in a remote delivery format organic chemistry laboratory course that allowed students to obtain customized data based on their experimental choices. We expanded this work to create an entire course of Twine choose-your-own-adventure laboratory activities for a third term organic chemistry laboratory course.

Cultivating Student Research Interests in Undergraduate Organic Chemistry Lab Course through Class Activity

Undergraduate organic chemistry laboratory courses act as a baseline for introductory scientific experimentation. These courses provide students with the knowledge and skills for their future careers. The traditional lab is conducted by providing a structured protocol of the experiment for the students to follow and reproduce the assigned task while collecting data and making observations when prompted. Though this confirmation-style approach is effective at imparting skills, it fails to demonstrate the true nature of scientific experimentation, which is discovery and problem-solving. To this end, we have redesigned the organic chemistry laboratory courses by using a “research-esque” discovery-style learning, in which certain experiments are treated as a research project. During the lab, reaction parameters within the experiment were varied by the students to compare their results with their peers, so as to create an opportunity to increase the understanding of the experiment at hand, pique the students’ interests in the subject, and create an environment that is similar to scientific research by redesigning the lab protocols. Some case studies are provided herein as samples of our pedagogical improvement.

Embedding equity, diversity, and inclusivity while teaching organic chemistry lab: An instructor’s perspective

Despite the increasing importance and recognition of equity, diversity, and inclusivity (EDI) within the academic and chemical industries, EDI is rarely implemented while designing some courses, especially during chemistry practical. Based on the instructor’s reflections and experiences, steps taken to include EDI as part of the organic chemistry laboratory course are discussed. Finally, suggestions for increasing equity and access to course materials while teaching remotely are presented. Despite the increasing importance and recognition of equity, diversity, and inclusivity (EDI) within the academic and chemical industries, EDI is rarely implemented while designing some courses, especially during chemistry practical. Based on the instructor’s reflections and experiences, steps taken to include EDI as part of the organic chemistry laboratory course are discussed. Finally, suggestions for increasing equity and access to course materials while teaching remotely are presented.

Critical Thinking through Literature Review in Organic Chemistry Laboratory Course

Critical Thinking through Literature Review in Organic Chemistry Laboratory Course

Considering alternative reaction mechanisms: students’ use of multiple representations to reason about mechanisms for a writing-to-learn assignment

Organic reaction mechanisms are often represented by the electron-pushing formalism and reaction coordinate diagrams. These representations pose a challenge to students because valuable information is encoded within each representation, and students must know how to reason about mechanisms using both. Hence, it is important to understand whether and how students consider these two representations when reasoning about reaction mechanisms. We have collected responses to a writing-to-learn assignment administered in a second-semester organic chemistry laboratory course to investigate students’ reasoning. The assignment was designed to elicit students’ reasoning about the most likely of two mechanisms for a catalyzed intramolecular aldol reaction when given the electron-pushing scheme and reaction coordinate diagram for both mechanisms. As part of the assignment, students submitted initial drafts, participated in content-focused peer review, and submitted revised drafts. We analyzed each component using a mixed methods approach to identify students’ reasoning about the most likely reaction pathway and how their reasoning changed after peer review and revision. In this article, we present a quantitative overview of changes students made about their decisions for the most likely reaction pathway and how these changes are related to providing and receiving feedback. Additionally, we present our analysis of the features of representations students used to reason about the likelihood of alternative reaction mechanisms. This study demonstrates how existing research about students’ reasoning with representations was operationalized for classroom practice using writing-to-learn. Furthermore, the analysis illustrates how writing-to-learn to can be used to develop students’ reasoning and offers implications for teaching students to reason about reaction mechanisms using multiple representations.

The Effects of Online Organic Chemistry Laboratory Videos on Students’ Perceptions and Intrinsic Motivation

The purpose of this exploratory study is to investigate students’ use and perceptions of online videos and intrinsic motivation toward the online videos in an organic chemistry laboratory course, which used online videos to assist students’ preparation and learning in the lab. Students’ responses to an anonymous survey showed that they watched the online videos one or more times based on their available time. Descriptive statistics showed that students had positive perceptions about the effect of online videos in terms of their preparation of labs, understanding the concepts, doing hands-on activities, and other aspects in the lab, which were consistent with their written comments. 44% of students showed positive intrinsic motivation toward the online videos according to items based on self-determination theory. Correlation results showed that the effect subscales were strongly related to each other, and students’ intrinsic motivation was significantly and positively related to students’ perceived effect of the online videos on their understanding and preparation with medium to large effect sizes. Inferential tests showed that students who had a positive perception of intrinsic motivation scored significantly higher on the understanding subscale with a medium to large effect size. The findings in this study suggest the online organic chemistry laboratory videos have significant potential to improve students learning and it is important to stimulate student intrinsic motivation toward the online videos which will help students benefits more from the effects of the online videos.

Proof of Concept for a Thin-Layer Chromatography Digital Badge Assignment Within a Laboratory Practical Exam for a Nonchemistry Majors’ Organic Chemistry Lab

Digital badges are credentials earned via a digital presentation to demonstrate the mastery of a technique. They have been utilized in General Chemistry laboratory courses as an assessment tool and to document students’ development of a skill. A digital badge assignment was developed for thin layer chromatography (TLC) and integrated into a laboratory practical exam in a large-enrollment Organic Chemistry laboratory course for science majors. The students filmed themselves carrying out the TLC technique while explaining why specific steps were taken. After completing the filming, they applied the TLC technique off-camera to identify an unknown. Detailed directions, filming prompts, and rubrics are provided for this digital badge. The assignment was updated on the basis of the results from quantitative and qualitative data collected from around 800 students and a dozen GTAs. This data was also analyzed to explore the affordances and challenges of implementing a badge within a laboratory practical. Data included students’ pre- and post-perceptions of their knowledge, experience, and confidence, scores on the laboratory practical and written final exam, and student and GTA responses to short-answer survey questions. The most helpful resources for the badge were the directions, filming prompts, and rubrics, while the challenges included filming oneself, time limits, and uploading videos to the learning management system (LMS). Overall, we believe the challenges students faced with the digital badge assignment were outweighed by the positive cognitive, psychomotor, and affective learning outcomes resulting from coupling a digital badge assignment with the identification of an unknown as complementary components of a required laboratory practical.

Nitrophenol Violet as a New Tool for Studying of Kinetics of Reactions in Solutions

This experimental lab set is for students taking college chemistry courses. It includes four laboratory works and completely illustrates the important parts of chemical kinetics, namely the determination of the rate constant and the determination of the factors influencing its value. They can be used in a laboratory set for a physical chemistry laboratory course, or separately, using only one or two of the four laboratory exercises for general, colloid, and organic chemistry laboratory courses, as well as biological and industrial catalysis. The experiment forms an understanding of the possibilities of controlling the reaction rate and an understanding of intermolecular interactions in solutions. The classical effects of the rate constant are considered, such as the effects of salt and solvent, as well as micellar catalysis. The main focus is on the following factors: increasing polarity of the medium or ionic strength decelerates the reactions between Dyez+ and HO– and accelerates that of Dyez– with HO–; solubilization of reagents by micelles of cationic, nonionic, and zwitterionic surfactants accelerates the reactions between Dyez+ and HO– and decelerates the reaction of Dyez– with HO–; anionic micelles decelerate both of them. Interest in micellar effects is due to both theoretical application in the study of reaction mechanisms, structure and dynamics of nanosized aggregates in solution, and practical application, for example, in organic synthesis, in industry. Quantitative data processing was carried out according to the Bronsted–Bjerrum and Scatchard equations, as well as linear dependences of solvation energies. The experiment also provides students with practical experience in using the spectrophotometer, as well as graphical and numerical analysis of the data obtained. A new anionic triphenylmethine dye 3,3′-dinitrophenolsulfonephthalein (nitrophenol violet, NPV) was proposed for the study of chemical kinetics. NPV reacts with alkali faster than anionic dyes such as bromophenol blue and phenolphthalein. This property of NPV reduces laboratory practice time.

Fragment-Based Ligand Discovery Using Protein-Observed 19F NMR: A Second Semester Organic Chemistry CURE Project.

Curriculum-based undergraduate research experiences (CUREs) have been shown to increase student retention in STEM fields and are starting to become more widely adopted in chemistry curricula. Here we describe a 10-week CURE that is suitable for a second-semester organic chemistry laboratory course. Students synthesize small molecules and use protein-observed 19F (PrOF) NMR to assess the small molecule's binding affinity to a target protein. The research project introduced students to multistep organic synthesis, structure-activity relationship studies, quantitative biophysical measurements (measuring Kd from PrOF NMR experiments), and scientific literacy. Docking experiments could be added to help students understand how changes in a ligand structure may affect binding to a protein. Assessment using the CURE survey indicates self-perceived skill gains from the course that exceed gains measured in a traditional and an inquiry-based laboratory experience. Given the speed of the binding experiment and the alignment of the synthetic methods with a second-semester organic chemistry laboratory course, a PrOF NMR fragment-based ligand discovery lab can be readily implemented in the undergraduate chemistry curriculum.