One Step Towards Green and Sustainable Chemistry: Replacing Harsh and Corrosive Acids in Organic Chemistry Teaching Laboratories

Dr. Shainaz Landge, Assistant Professor and Dr. Abid Shaikh, Associate Professor, Department of Chemistry ($10,023.00) Replaced toxic and corrosive acids such as hydrochloric and sulfuric acids from organic chemistry teaching laboratories with greener alternatives

Isomerization Mechanism in Hydrazone-Based Rotary Switches: Lateral Shift, Rotation, or Tautomerization?

Two intramolecularly hydrogen-bonded arylhydrazone (aryl = phenyl or naphthyl) molecular switches have been synthesized, and their full and reversible switching between the E and Z configurations have been demonstrated. These chemically controlled configurational rotary switches exist primarily as the E isomer at equilibrium and can be switched to the protonated Z configuration (Z-H^+) by the addition of trifluoroacetic acid. The protonation of the pyridine moiety in the switch induces a rotation around the hydrazone C═N double bond, leading to isomerization. Treating Z-H^+ with base (K_(2)CO_3) yields a mixture of E and “metastable” Z isomers. The latter thermally equilibrates to reinstate the initial isomer ratio. The rate of the Z → E isomerization process showed small changes as a function of solvent polarity, indicating that the isomerization might be going through the inversion mechanism (nonpolar transition state). However, the plot of the logarithm of the rate constant k vs the Dimroth parameter (E_T) gave a linear fit, demonstrating the involvement of a polar transition state (rotation mechanism). These two seemingly contradicting kinetic data were not enough to determine whether the isomerization mechanism goes through the rotation or inversion pathways. The highly negative entropy values obtained for both the forward (E → Z-H^+) and backward (Z → E) processes strongly suggest that the isomerization involves a polarized transition state that is highly organized (possibly involving a high degree of solvent organization), and hence it proceeds via a rotation mechanism as opposed to inversion. Computations of the Z ↔ E isomerization using density functional theory (DFT) at the M06/cc-pVTZ level and natural bond orbital (NBO) wave function analyses have shown that the favorable isomerization mechanism in these hydrogen-bonded systems is hydrazone–azo tautomerization followed by rotation around a C–N single bond, as opposed to the more common rotation mechanism around the C═N double bond

Introducing the Remote Mentoring of Undergraduate Research Students (ReMentURS) Workshop Series: Initial Evaluation and Plans for Wider Implementation

The primary objective of the Remote Mentoring of Undergraduate Research Students (ReMentURS) workshop series is to design a remotely available professional development training that will provide rigorous research concept and skills introduction to incoming undergraduate research students. This pilot run eight-week remote learning workshop series includes digital presentations, informational videos, virtual demonstrations, and aligned comprehension checks to foster student mindsets towards becoming independent research scientists. Preliminary assessment of the of ReMentURS program reveals that participants self-report gaining a variety of skills through the series and are likely to use the content in their future course and research laboratories. ReMentURS material can be shared with any undergraduate student who is interested in joining a research group to familiarize them with basic research techniques. Student learning gains will continue to be evaluated throughout the series and this initial assessment will be used towards the betterment of the future workshops

Incorporation of Molecular Simulation Program to Improve Students’ Understanding in Gas Chromatography Laboratory

Organic Chemistry is known as one of the “difficult course” in college curriculum. When any abstract theory is introduced, students have the misconception that they will not be able to learn the new material. Conventional teaching techniques can be blended with interactive teaching tools to convey the contents in an engaging manner. The major intention of this project was to utilize a free molecular simulation program such as NetLogo to deliver the “challenging” concepts such as Gas Chromatography in organic chemistry courses. The project was designed to promote “creative thinking” so students will understand and implement the information in advanced courses as well. The on-going study is carried over two semesters and this proposal will focus on the first semester (Fall 2015) results to see the impact of simulation program. The primary audience for this session would be the higher education chemistry students and professors

Microwave Assisted and Conventional Approaches towards the Synthesis of Trifluoromethylated Alcohol Derivatives

Trifluoromethylated alcohols were synthesized via various heating techniques such as with Microwave assistance and by Conventional means. The isomerized product separation was analyzed using differing instrumental characterization techniques. The detailed study was carried out using different bases and solvent. The regioselectivity of the product was altered with the change in solvent and base

Stereoselective Synthesis of α-Fluoro-β-Trifluromethyl-α-β- Unsaturated Esters by Horner-Wadsworth-Emmons Coupling

α-Fluoro-β-trifluoromethyl-α,β-unsaturated esters were synthesized via the reaction of diethyl (1-fluoro-1-carbethoxymethyl) phosphonate with a variety of aromatic/heterocyclic trifluoromethyl ketones and trifluoroacetaldehyde ethyl hemiacetal by the Horner-Wadsworth-Emmons (HWE) coupling. The effect of base, solvent, as well as reactant ratio has been investigated. The present method is highly stereoselective, attractive and convenient for the synthesis of the target compounds due to the availability of the reagents, simplicity of the approach and good yields of the products

Pilot Study for STARS (Self Tracking, Assessment and Reflection Study) in General Chemistry Course

In this time management study, we focused on a class of undergrad students in their first semester of chemistry (Principles of Chemistry I) course. The intended purpose for this project was to understand on how the use of instructor designed time management tools and intervention techniques relate to the student success as measured by exams and overall course grades. The overarching goal was to help them responsibly allocate their time and resources to focus more on their study habits and success. The expected outcome is a positive correlation between better study habits, more time spent studying, and higher overall exam grades. The final assessment was carried out by giving surveys to ascertain whether the tools were used and how their helpfulness was perceived

Pilot Study for STARS in General Chemistry course

Abstract: Managing time is the art which is carefully driven by the motivated students, while the less successful students often struggle. This study targets the use of instructor designed time management tools and intervention techniques and its relation to success as measured by exam grades and course grades in general chemistry course. Two sections of general chemistry I participated in this study. This study will help to investigate the assessment tools given to students. Results from this study will be used to streamline the procedure and surveys which can be used for future data collection in chemistry courses

Incorporation of Freshmen in Research for Early Experience (IFREE)

In this presentation, the researchers will describe the implementation of a new University Research Experience (URE) for undergraduate students in STEM fields. “Planned Progressive Pathways (P3): Incorporation of Freshmen in Research for Early Experience (IFREE)” is a program that will involve students in research beginning in their freshman year. Faculty members will measure students’ efficacy beliefs to examine if this has any influence on graduation rates. This project is a good fit for the SOTL as the researchers will describe student learning and developments as they gain experience as well as a deeper appreciation for STEM as a discipline

Enantioselective Friedel-Crafts Reaction of Indoles with Trifluoroacetaldehyde Catalyzed by Cinchona Alkaloids

The first direct asymmetric synthetic preparation of trifluoro-1-(indol-3-yl)ethanols (TFIEs) is described by an enantioselective organocatalytic method from indoles and inexpensive trifluoroacetaldehyde methyl hemiacetal. The reaction is catalyzed by hydroquinine to produce TFIEs in an almost quantitative yield and with enantioselectivities up to 75% at room temperature. The enantioselectivity is strongly dependent on the concentration of substrates and catalyst due to the competitive noncatalyzed reaction. Chirality, 2011. © 2011 Wiley-Liss, Inc