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A self-assembled Fe4L6 cage with internally oriented carboxylic acid functions was shown to catalyze a variety of dissociative nucleophilic substitution reactions that proceed via oxocarbenium ion or carbocation intermediates. The catalytic behavior of the cage was compared to that of other small acid catalysts, which illustrated large differences in reactivity of the cage-catalyzed reactions, dependent on the structure of the substrate. For example, only a 5% cage confers a 1000-fold rate acceleration of the thioetherification of vinyldiphenylmethanol when compared to the rate with free carboxylic acid surrogates but only a 52-fold acceleration in the formation of small thioacetals. Multiple factors control the variable reactivity in the host, including substrate inhibition, binding affinity, and accessibility of reactive groups once bound. Simple effective concentration increases or the overall charge of the cage does not explain the variations in reactivity shown by highly similar reactants in the host: small differences in structure can have large effects on reactivity. Reaction of large spherical guests is highly dependent on substitution, whereas flat guests are almost unaffected by size and shape differences. The cage is a promiscuous catalyst but has strong selectivity for particular substrate shapes, reminiscent of enzymatic activity.

Varying the functional groups in endohedrally functionalized self-assembled Fe4L6 cages allows control of binding affinity and stoichiometry, and fluorescence emission.

An endohedrally functionalized self-assembled Fe4 L6 cage complex can catalyze oxa-Pictet-Spengler cyclizations of tryptophols and various aldehyde derivatives, showing strong rate accelerations and size-selectivity. Selective molecular recognition of substrates controls the reactivity, and the cage is capable of binding and activating multiple different species along the multistep reaction pathway. The combination of a functionalized active site, size-selective reactivity, and multistep activation, all from a single host molecule, illustrates the biomimetic nature of the catalysis.

Academic institutions are faced with the complex problem of accurately determining the hazards associated with a proposed or ongoing project. For many reasons, compressed gas safety can be a signif...

Supporting and sustaining positive educational change is an area of increasing focus in higher education and remains a persistent challenge. Using student partnerships is one promising way to help promote these much-needed changes. This case study focuses on Departmental Action Teams (DATs), which are groups of faculty, students, and staff working together in the same department to make sustainable improvements to undergraduate education. Here we focus on DATs from four different departments, across two research-intensive universities in the USA, to draw attention to the important roles that students play as change agents in these groups. We also reflect upon the inherent challenges in building partnerships that incorporate meaningful power sharing to effect educational change

Due to the “wicked problem” of the Academy’s resistance to innovation, new teaching and learning programs struggle to become integrated into the fabric of the Academy, which slows the uptake of evidence-based practices. This wicked problem is rooted in the lack of slow, intentional mechanisms for cultural change in the Academy. In this article, we analyze the institutionalization journey of the Departmental Action Team (DAT) project, which is a model for slow, intentional change. Over the last four years, partnering with two campus centers for teaching and learning (CTLs) allowed the DAT project to make institutionalization progress.This analysis is focused on the institutionalization activities of the DAT project team and their co-creation of value with diverse stakeholders across two institutions. Results of the analysis include the definition of seven areas of effort (Team Development, Program Design, Awareness Communication, Program Implementation, Program Assessment, Outcomes Communication, and Financial Stability) that are valuable for the institutionalization of innovative educational programs. Within each area of effort, we describe specific strategies for institutionalization progress. We also analyze the timing of different areas of effort and present a model describing the cycling between areas of effort over time. Throughout the analysis, we provide recommendations for CTL staff working to institutionalize innovations.

A self-assembled Fe(II)(4)L(6) cage was synthesized with 12 internal amines in the cavity. The cage forms as the dodeca-ammonium salt, despite the cage carrying an overall 8+ charge at the metal centers, extracting protons from displaced water in the reaction. Despite this, the basicity of the internal amines is lower than their counterparts in free solution. The 12 amines have a sliding scale of basicity, with a ~6 pKa unit difference between the first and last protons to be removed. This moderation of side-chain basicity in an active site is a hallmark of enzymatic catalysis.

This article describes how a focus on outcomes can be a tool for guidingsystemic change. By focusing on positive outcomes to be achieved, agroup can guide its collective efforts toward an ideal future rather thanbecoming fixated on individual problems to solve. While there is supportfor an outcome-guided approach in the literature on individual and organizationalchange, this approach has not been used extensively to supportdepartment-level changes in science, technology, engineering, and mathematics(STEM) education.

A self-assembled Fe4 L6 cage complex internally decorated with acid functions is capable of accelerating the thioetherification of activated alcohols, ethers and amines by up to 1000-fold. No product inhibition is seen, and effective supramolecular catalysis can occur with as little as 5 % cage. The substrates are bound in the host with up to micromolar affinities, whereas the products show binding that is an order of magnitude weaker. Most importantly, the cage host alters the molecularity of the reaction: whereas the reaction catalyzed by simple acids is a unimolecular, SN 1-type substitution process, the rate of the host-mediated process is dependent on the concentration of nucleophile. The molecularity of the cage-catalyzed reaction is substrate-dependent, and can be up to bimolecular. In addition, the catalysis can be prevented by a large excess of nucleophile, where substrate inhibition dominates, and the use of tritylated anilines as substrates causes a negative feedback loop, whereby the liberated product destroys the catalyst and stops the reaction.

Self-assembly of a carboxylic acid-containing ligand into an Fe4L6 iminopyridine cage allows endohedral positioning of the acid groups while maintaining a robust cage structure. The cage is an effective supramolecular catalyst, providing up to 1000-fold rate enhancement of acetal solvolysis. This enhanced reactivity allows a tandem deprotection/cage-to-cage interconversion that cannot be achieved with other acid catalysts. The combination of rate enhancements and sequestration of the reactive function confers both activity and selectivity on the process, mimicking enzymatic behavior.

Context-based learning (CBL) is advocated as beneficial to learners, but more needs to be understood about how different contexts used in courses influence student outcomes. Gilbert defined several...

We study the effects of homeschool background and time use on academic performance among students at Patrick Henry College, a private religious institution with a 63-credit core classical liberal a...

The present study explored the experience and understanding of gender for gay and queer men who perform drag. It is part of a 20-year program of research focused on how LGBTQ gender identities arise, why they coalesce, and how they are enacted within their social contexts. Interviewers on this topic involving 18 participants were subjected to a grounded theory analysis. Drag genders were tied to common experiences of overcoming social messages that maligned femininity within men, an appreciation of performance arts, and a desire to use social power to confront issues of sexism, genderism, and/or heterosexism. At the same time, participants reported differences in experiencing gender as binary or fluid and in whether they experienced their gender as shifting when engaged in performance. The study contributes to the program of research on LGBTQ genders by examining how drag gender is both essential and constructed, and how it resist sets of oppressive values and is eroticized. It examines how gendered communication functions when performed for audiences and how the social position of these men is both elevated and stigmatized within LGBTQ community. Drag gender’s multiple meanings are credited to its position between gay and transgender politics within this socially transformative moment in time.

A self-assembled Fe4L6 cage is capable of co-encapsulating multiple carboxylic acid containing guests in its cavity, and these acids can act as cofactors for cage-catalyzed nucleophilic substitutio...

Cultivating institutional transformation has been of recent interest in education research. This theoretical paper presents six principles for supporting sustained change efforts at the department level. Considering change efforts at the level of “principles” is valuable because principles are grounded in theoretical and empirical knowledge, but are abstract enough to be adapted to many contexts. For each principle we argue for its value, drawing on previous literature in higher education, organizational change, discipline-based education research, and design thinking. We then give illustrative examples of how each principle was embodied within the Departmental Action Team (DAT) project. The DAT project facilitates the implementation of effective changes within university science, technology, engineering, and mathematics departments. We conclude with a discussion of how these principles can be applicable across a variety of institutional transformation efforts.

Four olive oils with varying amounts of total phenols were exposed to four different heating conditions. Chemical parameters such as free fatty acid, peroxide values, UV absorbency, total phenols, individual phenols, α-tocopherol, squalene, oleocanthal, fatty acid profile and smoke point were measured before and after heating to evaluate the impact of heating conditions on the oils. We found olive oils have reasonably high smoke point that is suitable for typical home-cooking conditions and fresh olive oil with low FFA and high phenolics are important for the conservation of olive oil quality and health benefits. A larger degree of oxidation occurred as with increase of heating time and temperature, oils with high level of phenols produced less polar compounds than oils with lower levels of phenols, including refined oils. A significant amount of total phenols and individual phenols such as oleocanthal remained after heating at 121 °C for 10 and 20 minutes, most of squalene stay intact even after heating at 220 °C.

Departments are now recognized as an important locus for sustainable change on university campuses. Making sustainable changes typically requires a shift in culture, but culture is complex and difficult to measure. For this reason, cultural changes are often studied using qualitative methods that provide rich, detailed data. However, this imposes barriers to measuring culture and studying change at scale (i.e., across many departments). To address this issue, we introduce the Departmental Education and Leadership Transformation Assessment (DELTA), a new survey aimed at capturing cultural changes in undergraduate departments. We describe the survey's development and validation and provide suggestions for its utility for researchers and practitioners.

Making decisions about the production and use of chemical substances is of central importance in many fields. In this study, a research team comprising teachers and educational researchers collaborated in collecting and analyzing cognitive interviews with students from 8th grade through first-year university general chemistry in an effort to map progression in students’ ability to make decisions about the consequences of using and producing chemicals. Study participants were asked to explain their reasoning about which fuel would be best to power a small vehicle. Data were analyzed using a “chemical thinking” lens to characterize conceptual sophistication and complexity of reasoning. Results revealed that most reasoning was intuitive in conceptual sophistication and relational in argumentative nature, driven by the consequences of using the fuels based on their composition. Implications are discussed for the design of learning experiences and assessments that better support students’ development of decisi...

Professional development that bridges gaps between educational research and practice is needed. However, bridging gaps can be difficult because teachers and educational researchers often belong to different Communities of Practice, as their activities, goals, and means of achieving those goals often differ. Meaningful collaboration among teachers and educational researchers can create a merged Community of Practice in which both teachers and educational researchers mutually benefit. A collaboration of this type is described that centered on investigating students’ abilities to apply chemical thinking when engaged in authentic tasks. We describe the design-based principles behind the collaboration, the work of the collaborative team, and a self-evaluation of results interpreted through a Communities-of-Practice perspective, with primary focus on the teachers’ perceptions. Analysis revealed ways in which teachers’ assessments shifted toward more research-based practice and ways in which teachers navigated t...

Given the diversity of materials in our surroundings, one should expect scientifically literate citizens to have a basic understanding of the core ideas and practices used to analyze chemical substances. In this article, we use the term ‘chemical identity' to encapsulate the assumptions, knowledge, and practices upon which chemical analysis relies. We conceive chemical identity as a core crosscutting disciplinary concept which can bring coherence and relevance to chemistry curricula at all educational levels, primary through tertiary. Although chemical identity is not a concept explicitly addressed by traditional chemistry curricula, its understanding can be expected to evolve as students are asked to recognize different types of substances and explore their properties. The goal of this contribution is to characterize students' assumptions about factors that determine chemical identity and to map how core assumptions change with training in the discipline. Our work is based on the review and critical anal...

The solving of problems in biochemistry often uses concepts from multiple disciplines such as chemistry and biology. Chemical identity (CI) is a foundational concept in the field of chemistry, and the knowledge, thinking, and practices associated with CI are used to answer the following questions: “What is this substance?” and “How is it different from other substances?” In this study, we examined the relevance of CI in biochemical contexts and first explored the ways in which practicing biochemists consider CI relevant in their work. These responses informed the development of creative exercises (CEs) given to second-­semester biochemistry students. Analysis of the student responses to these CEs revealed that students incorporated precursors to CI thinking in more than half of their responses, which were categorized by seven previously identified themes of CI relevant to the presented biochemical contexts. The prevalence of these precursors in student responses to the CEs, coupled with the examples provided by practicing biochemists of contexts in which CI is relevant, indicate that CI thinking is relevant for both students training to be biochemists and practicing biochemists.

The value of the concept of substance, both in its theoretical and phenomenological constructions, should be considered in the learning of chemistry. The central idea of chemical identity is defined to consist of the assumptions, knowledge and practices of chemists in determining whether substances are the same or not the same. Within a collaboration between two universities, one in Costa Rica and the other in the United States, an exploratory study was conducted to uncover trends and to validate empirically, within undergraduate and graduate levels of education, including professors, a hypothetical learning progression of chemical identity that was previously reported. This work is presented in two parts. In this first part, a brief history of the macroscopic concept of substance is presented, as well as a summary of the hypothetical learning progression of chemical identity and how it relates to the theoretical framework of chemical thinking. This manuscript precedes the second part in which the results, implications and conclusions are presented.ResumenEl valor del concepto de sustancia, tanto como construcción teórica y fenomenológica como macroscópica, debe ser considerado en el aprendizaje de la química. Este trabajo define una idea principal en química —identidad química— que consiste en las sugerencias, conocimientos y prácticas de trabajo de los químicos para saber si las sustancias químicas son diferentes o iguales entre sí. Dentro de una colaboración entre una universidad en los Estados Unidos y otra en Costa Rica, fue conducida una investigación exploratoria para descubrir tendencias y validar empíricamente una progresión de aprendizaje hipotética sobre la identidad química, que fue reportada anteriormente, para alumnos y profesores de pregrado y postgrado. Este trabajo es presentado a través de dos documentos. En el primero, a continuación, se presenta una breve historia del concepto macroscópico de sustancia, un resumen de la progresión de aprendizaje hipotética, y cómo se ubica dentro del marco teórico del pensamiento químico. Este manuscrito conduce al segundo trabajo en el que se presentan el marco analítico, y los resultados, implicaciones y conclusiones.