Constructing a Neural Scaffold for Teaching 1H NMR Spectroscopy to

Chapter 5

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Constructing a Neural Scaffold for Teaching 1H NMR Spectroscopy to Undergraduate Organic Chemistry Students Connie Gabel* and Rosemarie Walker Department of Chemistry, Metropolitan State University of Denver, Denver, Colorado 80217, United States *E-mail: [email protected]

Nuclear magnetic resonance (NMR) spectroscopy is a topic in the organic chemistry curriculum that is difficult for students to understand and to gain proficiency. Assessment of student knowledge indicated that students lacked a fundamental understanding of hydrogen environments, impact of functional groups, and interpretation of spectra. The Supplemental Instruction (SI) program at MSU Denver helps students to grasp the basic theory, usage, and analysis of 1H NMR spectroscopy. Previous research on the topic indicated that the methods used in the SI program needed to have more intensive scaffolding and a more consistent systematic approach to helping students learn 1H NMR spectroscopy. New methods that included more scaffolding in the curriculum, the Socratic Method, conceptual development, and group work were implemented across SI sessions. Students were assessed using pre-tests and post-tests which measured their understanding and ability to apply 1H NMR spectroscopy. Qualitative data were collected through a survey given to students at the end of the semester. Results indicate that neural scaffolding of 1H NMR spectroscopy in SI sessions helps students to better understand this topic.

© 2016 American Chemical Society Soulsby et al.; NMR Spectroscopy in the Undergraduate Curriculum: First Year and Organic Chemistry Courses Volume 2 ACS Symposium Series; American Chemical Society: Washington, DC, 2016.


Introduction Prior results have indicated the effectiveness of using neural scaffolding for teaching organic chemistry students topics such as nomenclature, polarity, bonding, and reaction types (1–5). This chapter will discuss the use of neural scaffolding to teach undergraduate organic chemistry students beginning topics of 1H NMR spectroscopy in a supplemental instruction (SI) setting. The introduction of spectroscopy into the organic chemistry curriculum at Metropolitan State University of Denver (MSU Denver) occurs either as a separate topic near the end of the first semester course or is incorporated as a regular part of the curriculum throughout the semester, depending upon the professor. SI is designed to parallel the professor’s lecture material. MSU Denver is located in downtown Denver and is a commuter campus that serves predominantly undergraduate students with 93% being from the metro Denver area. The university has open enrollment policies and a student body of 21,000 mostly non-traditional students with an average age of 26 years. MSU Denver is Colorado’s leader in providing students of color a STEM education, and the diversity of the campus mirrors that of the state’s demographics. The university ranks in the top 100 national colleges and universities for its Latino enrollment and for graduating students of color. The university’s student population statistics indicate that 32% are first generation college students, 33% are Pell grant recipients, and 54% percent are female students. The SI program was implemented to help increase students’ success rate in critical STEM classes such as organic chemistry. Student support of the program, as evidenced by attendance records and surveys, indicates that SI is very beneficial in helping them to efficiently complete chemistry classes that they need for graduation and for future careers. Qualitative and quantitative data indicate students’ difficulty in understanding 1H NMR spectroscopy as taught in organic chemistry courses (4). Specifically the findings reveal that students struggle to understand hydrogen environments, signals and multiplicity, to determine how functional groups affect chemical shifts, to recognize patterns, to compile the pieces of information to ascertain the structure, and to confirm that the final structure matches the data. The curriculum described in this chapter uses a constructivist framework to address some of these issues that students experience and to expand the amount of neural scaffolding utilized within SI sessions for 1H NMR spectroscopy at MSU Denver.

Supplemental Instruction Supplemental Instruction, a voluntary, structured peer assisted learning program targeting low success rate classes, was first implemented at Metropolitan State University of Denver in organic chemistry for the fall 2010 semester. SI Peer Leaders receive weekly pedagogical training by an experienced chemical educator in teaching techniques and in effective methods for teaching concepts in chemistry. They also receive additional assistance on an individual basis for developing curricular materials, for specific teaching techniques that work best for particular topics, and for help with conducting sessions. The SI Peer Leaders 62 Soulsby et al.; NMR Spectroscopy in the Undergraduate Curriculum: First Year and Organic Chemistry Courses Volume 2 ACS Symposium Series; American Chemical Society: Washington, DC, 2016.


for organic chemistry are undergraduate students who have an outstanding overall academic achievement record, a high grade in the organic chemistry course to which they are assigned, an exceptional understanding of the concepts covered in the course, professor recommendation, and ability to work well with other students to lead SI study sessions. The SI Peer Leaders for organic chemistry who have already graduated are currently enrolled in top graduate programs in chemistry or in dental and medical schools. At MSU Denver, SI sessions are approximately fifty minutes in duration and are held twice a week; sessions are usually held just before the class to accommodate the commuter students who comprise the student body. The benchmark used in comparing SI attendees versus non-SI attendees is an attendance of 50% or more of the SI sessions offered for the corresponding course. Organic chemistry SI sessions are popular with students, as indicated by both student feedback and the fact that some students attend SI sessions 75-100% of the time. The SI sessions are carefully planned by the SI Peer Leaders with the assistance of the chemical educator and more experienced SI peer leaders. The chemistry professor of the class is consulted on a regular basis as well, and the SI Peer Leader assigned to a course section attends all the lectures for that section. In addition to SI sessions, the SI peer leaders hold regular office hours each week for students who need more help or have scheduling issues. Based on student surveys, open office hours were implemented to meet the needs of students whose schedules did not match with SI sessions or regular office hours. For the open office hours, organic SI Peer Leaders work with students from any of the sections of a course at the department’s large blackboard wall, with instructional sessions focusing on questions posed by the students. All of these delivery methods are very popular with the MSU Denver students. Attendance at SI sessions, though voluntary, is strongly encouraged by faculty and peers, which often results in half or more of the students in the class attending SI sessions. SI is open to students of varying academic abilities; and at MSU Denver all academic levels, from students struggling to master key topics to top students wanting a better understanding of the material, are involved in the typical SI sessions. The goal of Supplemental Instruction is to teach students how to solve chemistry problems in groups and by themselves so that they can learn to work independently and confidently challenge new material. Therefore, the SI Peer Leaders at MSU Denver are trained in the use of neural scaffolding, chunking, questioning techniques, small group dynamics, and other teaching methods. These methods are the ones primarily utilized with the teaching of 1H NMR spectroscopy in SI sessions. Additionally, the SI Peer Leader attends the lectures for the class to which the SI is attached and is therefore familiar with the topics that the professor is currently teaching the students and the methods the professor is using. The SI Peer Leader consults regularly with the chemistry professor for the class.

63 Soulsby et al.; NMR Spectroscopy in the Undergraduate Curriculum: First Year and Organic Chemistry Courses Volume 2 ACS Symposium Series; American Chemical Society: Washington, DC, 2016.


Constructivism The methods and results discussed in this chapter are embedded in a constructivist theoretical framework. Originating in the cognitive sciences, constructivism is a theory of learning that involves understanding how people integrate newly learned material with their existing knowledge and then make sense of it (6, 7). Constructivism is applied extensively in chemistry and science education in general and is the dominant epistemology used in science education (8). Bodner (9) states that knowledge is actively constructed by people, and that these constructions are modified as they acquire new experiences. Learning is a complex process that may occur within a social context, but it is ultimately the individual who must learn the material (9). In summarizing the major principles of constructivism, Staver (10) includes as critical components actively building knowledge by the individual and by communities, and language-based social interactions in the building of knowledge. Piaget (11) portrayed individuals as active, not passive, participants in intellectual development. In the research reported in this chapter, the students in the SI sessions are actively involved in learning the material both individually and within a community of learners, and they learn to communicate using the chemical terms customarily associated with chemistry topics such as spectroscopy. Spectroscopy is a key component in constructing a web of knowledge in organic chemistry. Ultimately that web of knowledge is constructed within the individual’s neural network, but working in groups and learning the components of 1H NMR spectroscopy in a group setting are beneficial in this process. The SI Peer Leaders use primarily three different types of groups: whole group discussion, small groups, and pairs. The number of students attending the SI session determines the size of the groups. At the beginning of the semester, pairs and whole group discussion are used frequently; but as the number of students attending the SI session grows, the use of small groups consisting of three to five students increases. The SI session plan also influences the group size. Some topics are best presented to the entire group, especially when covering difficult material with which students are struggling to gain a basic understanding. However, working on problems is usually best in small groups. With large SI sessions, comparable problems are given to different small groups and then presented to the whole group. As students work together, they help each other to construct knowledge about 1H NMR spectroscopy. Pairing a stronger student with a weaker student benefits both students; the stronger student solidifies their knowledge by teaching it to someone else, and the less capable student gains a better understanding of the material since they have received guidance from a peer. For example, in an SI session students construct a table of multiplicities together as a whole group. Later in the session, the students work in small groups to determine the number of hydrogen environments and expected splitting pattern. By working either in a large group or small groups, students benefit by learning how to construct the knowledge that they will need to understand 1H NMR spectroscopy. The guidance of the SI Peer Leader is essential for helping the students in the session to construct this knowledge correctly. 64 Soulsby et al.; NMR Spectroscopy in the Undergraduate Curriculum: First Year and Organic Chemistry Courses Volume 2 ACS Symposium Series; American Chemical Society: Washington, DC, 2016.


Neural Scaffolding Neural scaffolding, which assists students in understanding difficult concepts by bridging gaps from mastered lower level knowledge to a higher level of knowledge with which they are struggling, has been a central component of the teaching methods utilized with students since the beginning of MSU Denver’s Supplemental Instruction program (1, 3). Neural scaffolding has been found to be effective for organic topics such as nomenclature, addition reactions for alkenes, substitution and elimination reactions, assigning R,S configurations, synthesis, electrophilic aromatic substitutions, acidity/basicity, and mechanisms (1, 2). Connecting general chemistry concepts such as electronegativity, polarity, and bonding to organic chemistry has also been taught using neural scaffolding (5). The basic process of applying neural scaffolding to organic chemistry is for the SI Peer Leader to recognize that the students are struggling with the concept, to identify the knowledge gap(s) by asking targeted questions, and to bridge the knowledge gaps using instructional methods that help the struggling students to gain an understanding of the material. Without the help of a more capable peer (12) such as an SI Peer Leader, the student would not be able to complete the task. In earlier work, Gabel (3) identified a number of key components for implementing neural scaffolding in organic SI sessions. These include reducing degrees of freedom, marking critical features, controlling frustration, and fading. The plan for incorporating neural scaffolding with 1H NMR spectroscopy is to first ascertain the challenges that students have in understanding the topic, and to then develop a systematic approach for addressing these challenges while applying the key components identified earlier. A number of major challenges with understanding 1H NMR spectroscopy were ascertained through SI sessions. The stumbling blocks fell into these four major categories: 1) information overload, 2) unfamiliar vocabulary, 3) lack of ability to incorporate new skills, and 4) inability to apply prior knowledge to spectroscopy (4). Often professors give organic students spectra and ask them to determine the structure of the organic molecule. Coupled with the stumbling blocks outlined earlier, this frequently leaves the students powerless to proceed to accomplish the task at hand. The methods described in this chapter are based on systematic neural scaffolding to help the student across the 1H NMR spectroscopy barriers one step at a time. Because the knowledge level is the most basic level of understanding (13), it was determined that the students first needed to learn about hydrogen environments and then link this concept to the number of signals anticipated in the 1H NMR spectrum. Furthermore, moving from the most elementary organic molecules to gradually more complex ones was essential for the neural scaffolding to be successful. Thus, a worksheet, a portion of which is shown in Figure 1, was developed for use in the SI sessions. Additionally, the worksheet would be used consistently across all SI sessions instead of having the SI Peer Leaders using different structures in the various organic sessions associated with different professors. Once the students comprehended the meaning of hydrogen environments and their associated link to number of signals expected in the spectrum, the students progressed to splitting patterns. This method requires students to explore hydrogen environments, signals and splitting patterns over 65 Soulsby et al.; NMR Spectroscopy in the Undergraduate Curriculum: First Year and Organic Chemistry Courses Volume 2 ACS Symposium Series; American Chemical Society: Washington, DC, 2016.


and over as they systematically move from simple molecules to more complex ones. The repetition is important in the retention of material (14). The goal is to aid memory formation as elucidated by research. The structural protein β-actin is believed to be involved in memory formation (15), and current research in this area by Singer (16, 17) supports the role of β-actin in long-term potentiation, a process in which the nerve cell synapses are stimulated again and again thus facilitating memory formation. Therefore, the process described above for teaching 1H NMR spectroscopy is designed to aid in memory formation.

Figure 1. Sample problems from first problem set given to students in SI sessions. The SI Peer Leaders helped develop the neural scaffolding packet for teaching 1H NMR spectroscopy with the help of the experienced chemical educator (Author

1). All of the organic chemistry SI Peer Leaders were given the same packet of information, worksheets to use, and answer keys. The SI Peer Leader packet summarized the important components of 1H NMR spectroscopy in the order that they were to be covered in SI sessions. First was hydrogen environments which was then linked to proton signals expected. (Figure 1). Next multiplicity was covered, and a completed table, shown in Table 1, was provided as a guide to show what the students in the SI sessions should construct with the assistance of 66 Soulsby et al.; NMR Spectroscopy in the Undergraduate Curriculum: First Year and Organic Chemistry Courses Volume 2 ACS Symposium Series; American Chemical Society: Washington, DC, 2016.

the SI Peer Leader. Drawing the 1H NMR spectrum signal patterns on the board reinforced this concept. Then chemical shifts were covered along with common functional groups. The table provided in the packet given to SI Peer Leaders included the information shown in Table 2. Again, the table is to be used as a guide by the SI Peer Leader to help students in the session construct a similar table on the board. Constructing spectra to show anticipated chemical shifts coupled with actual spectra reinforced this concept.


Table 1. Completed Table on Multiplicity for SI Peer Leaders To Use as a Guide in SI Sessions Peaks

Name

N+1 Rule

1

Singlet

No H Neighbors

2

Doublet

1 H Neighbor

3

Triplet

2 H Neighbors

4

Quartet

3 H Neighbors

5

Pentet

4 H Neighbors

6

Sextet

5 H Neighbors

7

Septet

6 H Neighbors

8

Octet

7 H Neighbors

Table 2. Information Given in SI Peer Leader Packet for General Chemical Shifts Signal

Chemical Shift (ppm)

Environment next to 1 oxygen

3.5 - 4

Environment next to 1 halogen

3.5 – 4

Carboxylic acid singlet

10 – 11

Aldehyde singlet

9 – 10

Alcohol singlet

Variable

Monosubstituted benzene

7–8

Di-substituted benzene

7–8

The SI Peer Leader packet also included worksheets containing 1H NMR spectroscopy problems for the students in the sessions. The chemical structures on the first problem set (Figure 1) began with methane, ethane, propane, butane, pentane, and hexane, and asked the student to identify the different hydrogen environments found in these molecules and then to give the number of signals expected. The students worked on these elementary problems before moving to 67 Soulsby et al.; NMR Spectroscopy in the Undergraduate Curriculum: First Year and Organic Chemistry Courses Volume 2 ACS Symposium Series; American Chemical Society: Washington, DC, 2016.


more complex ones that included substituents such as methyl groups. Gradually splitting patterns were introduced after students had an understanding of hydrogen environments. By designing the initial session in this fashion, the degrees of freedom were greatly reduced and allowed the students to focus on just two aspects of 1H NMR spectroscopy: hydrogen environments followed by multiplicities. This also diminished the information overload while emphasizing just two critical features of 1H NMR spectroscopy and decreased the level of student frustration. The purpose of this method was to allow the students to become more familiar with the vocabulary of 1H NMR spectroscopy and to comprehend how to apply it in simpler problems before moving on to more complex applications. At a later time, shielding and deshielding were introduced as this topic related to downfield shifting using organic compounds with oxygen, such as the problems shown in Figure 2.

Figure 2. Problems that contained oxygen given to students in SI sessions.

Likewise, they were instructed about the expected 1H NMR signals exhibited by common functional groups such as aldehydes, carboxylic acids, and alcohols as shown in Table 2. Afterwards, aromaticity was added, and students learned about the expected patterns with substituents on benzene rings. Sample problems are shown in Figure 3. Repetition is very important for establishing neural pathways in the brain. Through the processing and reprocessing of the material, it is more likely that the information will enter long term storage for later retrieval (14). By doing similar questions about hydrogen environments, number of signals, and number of peaks per signal, the student can reinforce these neural pathways. Integration was one of the last topics covered and it is included in the problems shown in Figure 3. Coupling constants and other nuclei such as 13C, 19F, and 31P were not covered in the SI session packets because the focus was on helping the students develop a foundation with proton NMR spectroscopy before expanding to other nuclei and more complex topics such as coupling constants. Likewise, topics such as contamination by solvent or starting material and the presence of side products in the 1H NMR spectrum were reserved for discussion by instructors and teaching assistants in the laboratory setting rather than being presented in SI sessions which were linked to organic chemistry lectures.



Figure 3. Portion of aromatic problem set given to students in SI sessions.

Results and Analysis Data Gathering and Statistical Methods Students in Organic Chemistry I classes that had SI attached were given a pre-test on the first day of class before any instruction occurred. Just before the end of the semester these students were given a post-test. Some of the questions were multiple choice; whereas other questions asked students to draw the structure of an organic molecule. It should be noted that the pre-test and post-test contained identical questions. The questions on these tests were not used for instructional purposes in any of the SI sessions. The data were tested for significant differences on the answers to questions that pertained to number of signals in the 1H NMR spectrum, splitting patterns, and drawing the correct structure for a given 1H NMR spectrum and the associated molecular formula. The structure was only counted correct if it was drawn accurately; there was no partial credit. Attendance was taken at each SI session throughout the semester, and those students who attended 50% or more of the sessions were classified as the SI group. Those who attended less than 50% of the SI sessions were in the non-SI group. Attendance at SI sessions was voluntary. The data from the two groups were compared using t-tests at the 95% confidence level on the post-test questions pertaining to 1H NMR spectroscopy. The t-tests were 2-tailed with unpaired samples and with unequal variance. As expected, students could not correctly answer the 1H NMR spectroscopy questions on the pre-test. Students in all Organic Chemistry I classes that had SI were also given a survey at the end of the semester that was used to gather the qualitative data. The organic chemistry classes did not have recitation sessions, but tutoring was available at the Student Academic Success Center on campus. Students could 69

Soulsby et al.; NMR Spectroscopy in the Undergraduate Curriculum: First Year and Organic Chemistry Courses Volume 2 ACS Symposium Series; American Chemical Society: Washington, DC, 2016.

also hire private tutors. There was no attempt to change the teaching style of the individual professors of each of the organic chemistry classes. All of the SI Peer Leaders were experienced at leading SI sessions except one.

Quantitative Data


On the pre/post-test, students were asked to predict the number of signals that they would expect from the 1H NMR spectrum of ethyl acetate using a multiple choice format as shown in Figure 4.

Figure 4. Question about number of signals for ethyl acetate spectrum. The results indicate that the students who attended SI 50% or more of the time did better than those who attended less than 50% with the SI attendees scoring 66% vs 58% for the non-SI attendees, a difference of 8% as illustrated in Figure 5.

Figure 5. Comparison of the results for number of signals expected for 1H NMR spectrum of ethyl acetate for the SI group versus the non-SI group. For the question regarding the number of signals for propyl acetate, Figure 6, both groups scored 63%, but the students who attended SI more than 50% of the time showed a 34% improvement from pre-test to post-test versus a 28% improvement for students who attended SI less than 50% of the time. Results are shown graphically in Figure 7. 70 Soulsby et al.; NMR Spectroscopy in the Undergraduate Curriculum: First Year and Organic Chemistry Courses Volume 2 ACS Symposium Series; American Chemical Society: Washington, DC, 2016.


Figure 6. Question about number of signals for propyl acetate spectrum.

Figure 7. Percentage improvement from pre-test to post-test for the question regarding the number of signals expected for the 1H NMR spectrum of propyl acetate for both the SI group and the non-SI group. When the results for predicting the number of signals for the two questions (Figures 4 and 6) are combined, the SI attendees scored 65% versus 60% for the non-attendees. The students were also tested on splitting patterns. The results (4) indicate that the students who attended SI 50% or more of the time did better on the 1H NMR spectroscopy question regarding splitting pattern of diethyl ether, as shown in Figure 8, than those who attended less. The results, as depicted graphically in Figure 9, were 70% for SI attendees versus 63% for non-SI attendees on the pre/post-test question shown in Figure 8.

Figure 8. Question about splitting pattern for diethyl ether CH2 protons. 71 Soulsby et al.; NMR Spectroscopy in the Undergraduate Curriculum: First Year and Organic Chemistry Courses Volume 2 ACS Symposium Series; American Chemical Society: Washington, DC, 2016.


Figure 9. Comparison of the results for splitting pattern expected for 1H NMR spectrum of diethyl ether for the SI attendees versus the non-SI group.

The ultimate goal in the SI sessions was for the students to gain depth of understanding of 1H NMR spectroscopy so that they could draw the correct structure given the spectrum. Students were asked to draw the chemical structure of C4H8O2 given the 1H NMR spectrum. Figures 10 and 11 illustrate this question.

Figure 10. Question regarding drawing the structure for C4H8O2 from 1H NMR spectrum.

The structure was only counted as correct if the student drew the structure for ethyl acetate. No partial credit was given. Findings indicate that the group who attended SI 50% or more of the time scored 10% better on the difficult question of drawing the structure with 33% of those students drawing ethyl acetate versus 23% for the non-attendees. Results are represented graphically in Figure 12. For a similar question regarding the spectrum for benzaldehyde, shown in Figures 13 and 14, comparable results were found.



Figure 11. 1H NMR spectrum for C4H8O2.

Figure 12. Comparison of the results between the SI and non-SI groups for drawing the structure from the 1H NMR spectrum shown in Figure 11.

Figure 13. Question on drawing structure for C7H6O from 1H NMR spectrum. 73 Soulsby et al.; NMR Spectroscopy in the Undergraduate Curriculum: First Year and Organic Chemistry Courses Volume 2 ACS Symposium Series; American Chemical Society: Washington, DC, 2016.


Figure 14. 1H NMR spectrum for C7H6O. These are shown graphically in Figure 15. We found that of those attending 50% or more SI sessions, 28% got the structure correct versus 18% for non-SI attendees, a difference of 10%.

Figure 15. Comparison of the results between the SI and non-SI groups for drawing the structure given the 1H NMR spectrum shown in Figure 14. For the question shown in Figure 16 and its accompanying 1H NMR spectrum shown in Figure 17 the results were more dramatic, with 43% of the SI-attendees getting the question correct and only 19% of the non-SI attendees drawing the correct structure for 4-bromophenol, a difference of 24%.

Figure 16. Drawing the structure for C6H5OBr from 1H NMR spectrum. 74 Soulsby et al.; NMR Spectroscopy in the Undergraduate Curriculum: First Year and Organic Chemistry Courses Volume 2 ACS Symposium Series; American Chemical Society: Washington, DC, 2016.


Figure 17. 1H NMR spectrum for C6H5OBr.

The results are portrayed graphically in Figure 18.

Figure 18. Comparison of the results between the SI and non-SI groups for drawing the correct structure for C6H5OBr given the 1H NMR spectrum.

The t-tests indicate that there was not a significant difference between the SI and the non-SI groups on the questions pertaining to number of signals. The data were examined by the individual questions as well as aggregated. However, on the questions asking the students to draw the correct structure given the molecular formula and the spectrum, there was a significant difference between the two groups at a 98% confidence level (p < .02, N = 175). 75 Soulsby et al.; NMR Spectroscopy in the Undergraduate Curriculum: First Year and Organic Chemistry Courses Volume 2 ACS Symposium Series; American Chemical Society: Washington, DC, 2016.

Qualitative Data


Students were given a survey asking whether they liked the method used for teaching 1H NMR spectroscopy in SI sessions. Of the results, 89% responded positively, 9% gave a neutral response, and only 2% were not in favor of the method. Students were also given an open-ended question asking why they did or did not prefer the method. The following comments were made by students in their responses: Student 1: “The SI Leader has given us procedures and keeps reinforcing it and we do a few problems every time. It has been very helpful.” Student 2: “It breaks down a complicated concept into easy to digest pieces. It was great.” Student 3: “The step-by-step method makes the problems more approachable.” Student 4: “I liked going over examples, solving problems together.” Student 5: “Repetition in practice problems.” Student 6: “We’ve been going over practice problems which I really needed so that I could understand how to begin and complete them.” Student 7: “It helps to look at NMR and try to understand why we get the molecule that we do.” Student 8: “It explains specific parts before putting it all together.” Student 9: “By fundamentally understanding it, I can approach problems better.” Student 10: “I found the practice and method to be very helpful.” Student 11: “It does a great job explaining and breaking things down.” Student 12: “I understood it so well, that was one of the best parts of this class.” Student 13: “That was one of the easiest portions of the course to understand.” Student 14: “…a better understanding on how it was broken down into steps.” Student 15: “Nice packets.” Students were also asked to give their suggestions for improvement. The responses primarily fell into two categories. Some students indicated that no changes were needed, while others wanted more practice, more examples, and more handouts. Additionally, the SI Peer Leaders were asked to comment on what they thought of the new method and their assessment of the sessions devoted to 1H NMR spectroscopy. All of the SI Peer Leaders supported the new method, and they believed the additional scaffolding made the teaching of 1H NMR spectroscopy easier for the students to follow. They also responded that the packet given to the SI Peer Leaders made it easier for them to plan these sessions and was consistent across all sessions of organic chemistry. They indicated that they received many positive verbal responses from the students in the sessions. 76 Soulsby et al.; NMR Spectroscopy in the Undergraduate Curriculum: First Year and Organic Chemistry Courses Volume 2 ACS Symposium Series; American Chemical Society: Washington, DC, 2016.


Discussion The results indicate that even though students who attended 50% or more SI sessions 50% did better than those who attended less or not at all, there was only a significant difference in performance on the questions asking the students to draw the structure of the organic molecule. The questions asking about number of signals were similar to those in the packets that were reviewed during SI sessions, but the students also attended lectures given by the professors of the various classes. No attempt was made to change how the professors taught their classes. Therefore, students might learn this material well enough from lecture, and only those students who were having difficulty or wanted more depth of understanding attended the SI sessions. However, the questions pertaining to drawing the organic structures for molecules require a higher level of understanding (13) and involved more analysis and synthesis than the questions on signals. It appears that the scaffolded problems that students worked during SI sessions built a better foundation and provided enough repetition to reinforce their neural networks. This allowed them to do a better job analyzing and synthesizing the 1H NMR spectroscopy material for the more difficult questions. The qualitative data indicate overwhelming support by the students for the neural scaffolding method that was used in the SI sessions. The only negative response indicated that the student preferred to learn 1H NMR spectroscopy using spectra. Suggestions for improvement reveal that students want more practice problems not less. Additionally, all of the SI Peer Leaders endorse the neural scaffolding method for teaching 1H NMR spectroscopy in SI sessions. Further verification of the method was obtained from the many positive comments that the SI Peer Leaders received.

Conclusions The open-ended responses from students indicate that they preferred to learn NMR spectroscopy by the neural scaffolding approach. This method allows for a gradual learning of the material so that a solid foundation is established in comprehension of hydrogen environments and the associated connection to number of signals in the 1H NMR spectrum before progressing to splitting patterns. This was followed by the introduction of concepts related to downfield shifting. It was decided that the discussion in SI sessions would focus on molecules containing oxygen to help the students develop an understanding of the meaning of downfield shifting and the correlation to spectra of molecules containing oxygen. Constructing the anticipated spectrum as well as teaching with the actual 1H NMR spectrum was used throughout the neural scaffolding to allow students to visualize the signals on a spectrum and how this related to the material being covered in lectures. Major functional groups were also covered, and students had the opportunity to see how these usually appeared on the spectra. Aromatic rings were introduced last and discussions included patterns students could expect to see from various 1H


example molecules such as those with para substituents. Students were also introduced to integration in SI sessions. Even though the neural scaffolding approach was only used in SI sessions, this method could apply equally well to classroom usage. Incorporation of the problem sets into group work and other active learning methods would be the best fit. Some of the items could be developed as clicker questions or used in on-line applications.


Acknowledgments The authors would like to acknowledge the following chemistry professors who agreed to have SI attached to their organic chemistry classes: Susan Schelble, Russell Barrows, Milton Wieder, Anna Marie Drotar, Donald McElwee, and Ethan Tsai. The authors would also like to acknowledge the following students who served as SI Peer Leaders for organic chemistry and who assisted in the development of the neural scaffolding model for 1H NMR spectroscopy presented in this chapter: Dustin Politica, Ryan Fitt, Michiko Nakajima Paschall, Dan Radulovich, Alicia Gamble, Jeremy O’Brien, Jed Wilson, Samuel Gordon, Joseph Salazar, Devin Rourke, Mitchell Magrini, Nicholas Kuehl, Sean Norris, and Igor Merkhasin. The Supplemental Instruction program would not be possible without the many students who attended the SI sessions and participated in this research. Metropolitan State University of Denver received grant monies from several sources to support the Supplemental Instruction program: National Institutes of Health grant 5R25GM058381-07, Grant 3R25GM058381-07S1 funded by ARRA monies, and National Science Foundation Scholarships in Science, Technology, Engineering, and Mathematics (S-STEM) DUE Award 1259336. The authors would also like to acknowledge support from the MSU Denver Chemistry Department and the Metropolitan State University of Denver School of Letters, Arts & Sciences Dean’s Office and the Auraria Higher Education Center. Approval was received from the Institutional Review Board at Metropolitan State University of Denver to collect and use the student data and their comments for publication.

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