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Immersive Virtual Reality (iVR) can help students visualise and explore complex chemical concepts, such as protein enzyme structures and interactions. We designed a set of collaborative iVR-based learning tasks on the interaction between a protein enzyme and its substrate. We investigated how 18 pairs (36 students) in undergraduate chemistry courses changed their understanding of enzyme–substrate interactions through iVR learning tasks. Videos of pre- and post-interviews and student-generated diagrams were analysed. Before iVR, students had abstract models of the structure of a protein enzyme or its interaction with a substrate molecule. Over 90 per cent of the students (33/36) explained enzyme–substrate interactions using simplistic lock-and-key diagrams, exclusively focusing on the shape. Although many students employed key scientific terms like activation energy in their explanations, they were unsure how enzymes lowered activation energy or how catalytic reactions occurred. After iVR, all students discussed the inadequacy of 2D diagrams for representing complex enzyme–substrate interactions. About 90 per cent of students (32/36) used concrete ideas such as electron density and orientation of reactants in the active site to explain the probability of successful interactions between the enzyme and its substrate. Our findings provide evidence of how interactive iVR learning tasks can help students explore complex molecular structures, integrate ideas, and build a concrete understanding of challenging science concepts.

Recent studies have reported a growing trend of using student-generated diagrams for assessment in science teaching and research. However, many educators tend to use diagrams to explore students’ perceptions of scientists and their work rather than explore conceptual understanding of abstract concepts. In this study, we used diagrams to investigate students’ conceptual understanding of the nature of hydrogen bonds among water molecules in snowflakes. Participants were 70 first- and second-year university students. Following a sequence of interview prompts, the students drew diagrams to illustrate the interactions amongst water molecules in snowflakes. Sixty students’ diagrams were analyzed inductively using a constant comparison method. Most diagrams showed that the students did not have major challenges drawing the water molecule structure, recognizing polarity of a water molecule, or recognizing the intermolecular nature of hydrogen bonds. However, the diagrams revealed varied ways in which students conceptualized the formation of hydrogen bonds. A third of the diagrams revealed students’ alternative conceptions about the role of lone pairs of electrons in the formation of hydrogen bonds. Most diagrams which showed a good understanding of the nature of a hydrogen bond revealed students’ difficulties in recognizing molecular interactions in a 3D space. Our findings suggest that student-generated diagrams can provide a powerful way to understand students’ conceptions of abstract science concepts.

In recent years, chemistry educators are increasingly adopting immersive virtual reality (IVR) technology to help learners visualise molecular interactions. However, educational studies on IVR mostly investigated its usability and user perceptions leaving out its impact on improving conceptual understanding. If they evaluated students’ knowledge gains, they tended to use information recall tests to assess knowledge gains. Employing interviews and diagram-drawing tasks, this study explored how students’ conceptual understanding of the nature of hydrogen bonds and the shape of snowflakes changed through a collaborative IVR experience on snowflakes. Participants were 68 undergraduate chemistry students. Videos of pre-/post-interviews and student-generated diagrams were analysed. The results indicated a marked improvement in students’ conceptual understanding of the nature of hydrogen bonds among water molecules in snowflakes. After IVR, 57 students provided scientifically acceptable explanations of the nature of hydrogen bonds. Improvements in students’ understanding were related to the intermolecular nature of hydrogen bonds, the role of lone pairs of electrons in forming hydrogen bonds, and molecular interactions in 3D space. This study suggests that collaborative IVR could be a powerful way for students to visualise molecular interactions, examine their alternative conceptions, and build more coherent understanding. Implications for the design and implementation of IVR activities for science learning are discussed.

ABSTRACTEngineering degree programmes include a significant amount of practical work for which national accrediting bodies stipulate a set of laboratory-learning outcomes. This paper sets out to understand how students’ interactions in the laboratory contribute to the attainment of laboratory-learning outcomes. The investigation was conducted in the traditional face-to-face laboratory mode. Results from surveys of final-year students and instructors are reported. Students’ and instructors’ perspectives of the relative importance of four main types of student interaction to meet each of the Engineers Australia laboratory-learning outcomes are also presented. Students primarily expected to interact with instructors more than with students (directly or through observation of interactions) or equipment for their achievement of the learning outcomes, whereas instructors reported that all of the interactions are important to achieve the learning outcomes.

Laboratories play a crucial role in the undergraduate science curriculum and the effectiveness of learning in laboratories is influenced by learners’ interactions with other students, the instructors, and the equipment used. In this study, a pre-lab survey was used to collect information about students’ expectations of interactions in chemistry laboratories and how they can be ranked according to their importance. Post-lab surveys were used to capture students’ perspectives about the frequency of interactions that existed in laboratory sessions they had completed. Direct observations of some laboratories were also conducted principally to validate students’ self-reported interactions. The data were also sorted by three levels of student achievement in order to relate students’ expectations of the importance of different interactions (pre-lab survey) and their self-reported frequency of interactions (post-lab survey) with their laboratory grades. Results from the pre-lab survey showed that student–instructor interactions were anticipated to be the most important ahead of conducting the laboratory activity, whereas results from the post-lab surveys showed that the most frequent interactions occurred between students. Students’ self-reports (post-lab survey) and the direct observations agreed well suggesting that the post-lab survey is a robust tool for capturing the frequencies of student interactions in this and future studies. The results also showed that students gaining high grades both anticipated the importance of, and then engaged more frequently in, two-way communications with both students and instructors whereas students with lower grades placed a relatively higher reliance upon passive interactions such as the pre-lab briefing, the laboratory manual and internet sources. Finally, recommendations are offered to curriculum designers, instructors and students based on the overall findings of the study.

AbstractAssessment of students’ performance in laboratory activities evaluates students’ achievements and weaknesses in practical work. This is vital from both student and institutional perspectives. Practical skills assessment methods evaluate students on three major components: the ability to collect data and perform calculations, to analyse the cause of failures in the process, and finally students’ active engagement and participation in the practical work. A conventional, report-based, assessment method combined with an alternative method, termed in-class assessment, were developed and used for second-year Fluid Mechanics laboratory work. In this article, we describe these two approaches and present the results of a quantitative investigation of students’ responses. Students expressed similar experience and satisfaction levels for each of the assessment methods that measured the attainment of different but essential personal and professional skills stipulated by the professional body for students graduating with an engineering degree. These skills include the development of research skills, conceptual understanding, application of techniques, preparing a report, team working abilities and the communication skills needed to interact with peers and demonstrators effectively. This article shows that the use of in-class assessment can serve as a useful complement to conventional report-based assessment methods ensuring optimal laboratory learning for students across engineering knowledge and skills areas.

Human African Trypanosomiasis (HAT), a neglected disease endemic in Sub-Saharan Africa, is usually fatal if left untreated. It is caused by the parasite Trypanosoma brucei, and is spread by the tsetse fly. The drugs currently available to treat HAT are few, and limited in efficacy. Furthermore, resistance towards these drugs is beginning to grow. In the last 25 years, only one advance has been made into HAT treatment and consequently, there is an increasing need for new drugs to be sought that are able to effectively treat this disease. This review provides a brief overview of drug discovery research for HAT, focusing on research published in the last four years, identifying new molecules with the potential to be developed into anti-HAT agents. The methods of drug discovery have been grouped into three key areas; new molecules inspired by known antitrypanosomal agents, target-based screening, and phenotypic screening.

This one-semester, mixed methods study underpinning social cognition and theory of planned behaviour investigated the attitudes, self-efficacy, and experiences of 559 first year undergraduate chemistry students from two cohorts in modified process-oriented guided inquiry learning (POGIL) classes. Versions of attitude toward the study of chemistry (ASCI v2), and chemistry attitudes and experiences questionnaire (CAEQ) were adopted, modified, and administered to understand and gauge students’ affective outcomes before (pre) and after (post) POGIL intervention. Students’ post-POGIL perceptions of their attitudes, self-efficacy and experiences were statistically significantly higher. In addition to confirmatory testing of reliability of data obtained from ASCI v2 and CAEQ in an Australian POGIL context, the findings suggest that POGIL intervention provides positive affective experiences to students who are new to chemistry or have limited prior chemistry knowledge.

Various studies have found a trend connecting diabetes mellitus or carbohydrate malabsorption syndromes to kidney stone formation. However, the underlying mechanism causing this impact is unclear. This study aimed to investigate whether some of this correlation is due to the underlying chemistry of sugars as crystal growth modifiers. Thus, the impact of major dietary monosaccharides (glucose, fructose, and galactose) and disaccharides (lactose and sucrose) on the formation of calcium oxalate was investigated from a crystallization perspective. The nucleation rate of calcium oxalate generally showed a promotion when monosaccharides were present. An analysis of the crystals with Raman spectroscopy found that signals for the monosaccharides are present within the crystal, showing an association between the sugars and calcium oxalate. When lactose was present, there was an obvious promotion of nucleation. When sucrose was present, an interaction with both the crystal and the solution ions was observed. The presence of galactose had the most influence on the zeta potential of calcium oxalate when zinc ions were present, resulting in the smallest zeta potential value. These results suggest that the sugars in urine may promote calcium oxalate formation and agglomeration, and this may suggest a chemical connection to the higher prevalence of stones in diabetic patients.

Magnetic molecular models help students explore molecular structures and interactions. In this study, we investigated how pairs of students used magnetic models to explore hydrogen bonding and the 6-fold symmetry of snowflakes. Fourteen first-year students enrolled in a chemistry unit participated in pairs. Students’ interactions with the magnetic models and their peers were video recorded and later transcribed. Students’ hand-drawn diagrams, verbal explanations, and gestures were used to evaluate students’ conceptual understanding. Students showed distinctly different patterns of interaction depending on their prior knowledge of hydrogen bonding and how they socially interacted. Pairs with alternative prior understanding of hydrogen bonding relied on prompts while using magnetic models to feel the attraction and repulsion between two water molecules. They then constructed a tetrahedral structure and discussed its similarities with the branches of snowflakes. Pairs with a better understanding of hydrogen bonding interacted more with each other, used magnetic models to create ring structures, and explained their similarities with the 6-fold symmetry of snowflakes. Despite gaining a new understanding of hydrogen bonding, most student pairs’ explanations did not extend to the massive 3D expansion of molecular structures to form a snowflake. Educators should consider the affordances of magnetic models and students’ group dynamics when teaching molecular interactions to explain macroscopic-level phenomena.

Pedagogical practitioners who emphasise active learning in undergraduate chemistry courses widely use the Student Assessment of Learning Gains (SALG) instrument to measure students' perceptions of their gains in knowledge and skills in chemistry. Although numerous studies have reported SALG results in support of successful pedagogical interventions, a comprehensive construct-verified version measuring students' perceptions of their chemistry learning is lacking. This paper aims to identify latent constructs of the SALG instrument that was administered in Process Oriented Guided Inquiry Learning (POGIL) classes by using exploratory and confirmatory factor analyses. When the SALG was administered on two separate occasions with two different groups of students following four weeks of instruction on topics in stereochemistry, the results revealed a four-factor structure consisting of 32 items that included Active Learning, Concept Learning, Resources, and Process Skills. These findings demonstrate an approach to collect evidence to support the match between intended constructs and measured variables in light of a targeted pedagogical intervention.

The preparation of a series of diastereoisomeric tetracamphorsulfonates derived from racemic tetramethoxyresorcin[4]arenes was achieved by reactions with an excess of (S)-(+)-10-camphorsulfonyl chloride in pyridine followed by isolation using flash chromatography. Tetradeprotonation of a number of tetramethoxyresorcin[4]arenes using n-butyllithium in tetrahydrofuran, followed by reactions using (S)-(+)-10-camphorsulfonyl chloride, gave the same tetracamphorsulfonates. Mono-, di- and tricamphorsulfonates were also prepared following selective deprotonation. In the reactions with tetraisopropyloxy- and tetracyclopentyloxyresorcin[4]arenes, only the mono- and dicamphorsulfonates were formed. X-ray crystallographic analysis established the absolute configurations of three diastereoisomerically pure tetracamphorsulfonates, including a diastereoisomer prepared from 6,12,18,24-tetramethoxy-2,8,14,20-tetrakis(2-methylpropyl)resorcin[4]arene. An additional pair of diastereoisomers was also prepared using (R)-(–)-10-camphorsulfonyl chloride and 6,12,18,24-tetramethoxy-2,8,14,20-tetrakis(2-methylpropyl)resorcin[4]arene, for one of which the structure was confirmed by an additional X-ray structure determination. Hydrolytic removal of the camphorsulfonyl residue(s) from the various diastereoisomers gave enantiomers of known absolute configurations. In some cases, the chiral nonracemic tetraalkoxyresorcin[4]arenes were converted into known tetrabenzoxazine derivatives by using N,N-bis(methoxymethyl)[(S)-(–)-(α-methylbenzyl)]amine in thermal or microwave-assisted reactions. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

The measurement of the pKa of racemic tetramethoxyresorcin[4]arenes explains the failure to obtain good yields in attempted Mannich reactions of these substrates under classical reaction conditions. The failure is related to the lack of adequate concentrations of the iminium ions that results from the reduced acid strength of tetraalkoxyresorcin[4]arenes compared with that of the parent octahydroxyresorcin[4]arenes. However, the preparation of a series of Mannich bases derived from racemic tetraalkoxyresorcin[4]arenes was accomplished under microwave-assisted aprotic reaction conditions and the use of preformed iminium ion intermediates. When the reactions were carried out with the use of chiral bis(aminol) ethers, mixtures of diastereomers were obtained that could be separated by flash chromatography. The absolute configurations of the enantiomerically pure tetrabenzoxazine derivatives were established in some cases by X-ray crystallographic analysis and by a comparison of the nuclear magnetic resonance spectroscopic data. The alkylation of racemic tetramethoxyresorcin[4]arenes was achieved with the use of an excess of 2-bromo-N-[(R)-(+)-(α-methylbenzyl)]acetamide in acetonitrile containing potassium carbonate. Enantioselective ligand-assisted reactions of aromatic aldehydes are also reported with the use of dialkylzinc reagents both in the absence and in the presence of terminal alkynes.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

Structural studies have confirmed that it is possible to exploit the relatively low nucleophilicity of the “external” amino substituents on the Co^III complex of 1,8-diaminosarcophagine (“sarcophagine” = sar = 3,6,10,13,16,19-hexaazabicyclo[6.6.6]icosane) in acylation and alkylation reactions leading to a variety of functionalized cage amine complexes. With the appropriate choice of solvent, all these reactions can be conducted with high efficiency, and the new complexes display properties foreshadowing the application of cage systems in, for example, electroactive polymers.

Characterisation, largely through crystal structure determinations of their metal complexes, of the polyamine products of several reactions between (in all but one case) polyalcohol benzenesulfonates and 1,2- and 1,3-diamines, confirmed that intramolecular reaction pathways are important only in the 1,2-diamine reactions. Even under conditions where the amine reactants are in large excess, however, it is possible to obtain products resulting from alkylation of a diamine by more than one molecule of sulfonate (or, in one case, of a bromochloroalkane). In metal ion complexes formed by the new ligands there are examples of only partial coordination of the N-donor sites, giving species which might be suitable for further, selective functionalisation at the unbound centres. Conversion of the complexes into macrocyclic derivatives also suited to further functionalisation is straightforward.

A remote laboratory that measures the enthalpy of vaporization (ΔHvap°) and the entropy of vaporization (ΔSvap°) of n-octane was designed, constructed, and offered to second-year physical chemistry undergraduates at the University of New England (UNE) and Curtin University. The experiment was delivered in real-time, using equipment controlled remotely via the internet. A survey instrument was developed to investigate the learning process from the students’ viewpoint and was followed by focus group interviews. Guidance from the laboratory manual and from the visual hints available through the webcam was important for their learning and was used most frequently among all the interactions. The students were satisfied with the laboratory and would like to perform other remote experiments. Types of learning interactions, such as experiment construction and technical skill learning, could be partly achieved with support from technicians and the meticulous design of online guidance.

A series of six calix[4]arene derivatives bearing allyl groups and/or benzyl groups functionalized at the phenolic oxygen atoms were synthesized and their cation-binding abilities for silver(I) and thallium(I) ions were evaluated through solvent extraction experiments. The results showed that both silver(I) and thallium(I) picrates were readily extracted by the tetrasubstituted p-t-butylcalixarene derivatives, while no extraction of sodium or potassium picrates was observed. The high extractability of thallium(I) picrate by these ligands was independent of the functional groups present, but the extraction of silver picrate seemed to be dependent on the conformational rigidity of the calixarene; those locked into the cone conformation showed the highest extractability for silver picrate.

Syntheses and room-temperature single-crystal X-ray structure determinations are recorded for an array of p-t-butylcalix[n]arenes, n= 4 or 6, diversely functionalized at the phenolic oxygen atoms: the 1,3-diallyl 2,4-dimethyl ether for n= 4 (1), the hexaallyl ether for n= 6 (2), and the 1,3-dibenzyl 2,4-bis(dimethylthiocarbamoyl) derivative for n= 4 (3), with a view to establishing ligand baseline conformations for subsequent metal complexation studies, and for exploring any inclusion properties. Compound (1) is monoclinic, P21/c, a16·751(9), b20·772(7), c27·91(1) Å, β 99·39(4)°, Z= 8, conventional Ron |F| being 0·060 for No4396 'observed' (I> 3σ(I)) reflections. Compound (2) is triclinic, P-1, a19·63(2), b14·57(2), c14·188(9) Å, α 107·84(8), β 93·26(7), γ 99·48(10)°, Z= 2, R0·067 for No7315. Compound (3), as its methanol monosolvate, is triclinic, P-1, a15·592(4), b15·17(3), c14·31(2) Å, α 88·8(1), β 64·3(1), γ 75·7(1)°, Z= 2, R0·076 for No3802. The conformation of (1) is similar to that previously established for an analogue in which two of the t-butyl groups were absent; the conformation of (2) is that of a flattened 1,2,3-alternate form, the asymmetric unit being a pair of half (centrosymmetric) dimers; the conformation of (3) is 1,3-alternate.

Alkylation of p-t-butylcalix[6]arene with ethyl bromoacetate results in a mixture of product ethers from which a tetraether can most easily be isolated in moderate yield; this product exhibited a degree and pattern of substitution which were unexpected given the literature on reactions of this type. A room-temperature, single-crystal X-ray study shows the tetraether compound to be triclinic P-1, a16·375(5), b14·296(9), c10·29(2) Å, α 72·4(1), β 87·12(9), γ 72·22(4)°, Z= 1; conventional Ron |F| was 0·095 for 2858 independent 'observed' reflections. The molecule is disposed about a crystallographic inversion centre and adopts a 1,2,3-alternate conformation distorted by different ethoxycarbonylmethyl substituent dispositions within the inversion-related halves. The benzene molecules occupy lattice sites between the calixarene molecules and are well removed from inclusion in the calixarene cavity, which is largely blocked by two of the ethoxycarbonylmethyl substituents.

The Mitsunobu reaction has been of much use in general synthetic organic chemistry. The major drawback of this reaction has been the removal of the by-products triphenylphosphine oxide and the dialkyl hydrazinedi-carboxylate. We report here that (p-dimethylaminophenyl)diphenylphosphine, an alternative phosphine, greatly assists the work-up procedure of this useful reaction.

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The article discusses changes in the methods of teaching chemistry under the Active Learning in University Science (ALIUS) project in Australia. The project aims to improve the lecture attendance among college students which makes them actively engaged in their learning. The Australian Learning and Teaching Council funds the project with programs including lectures, didactic teaching methods and monocultural learning environments.

The article discusses project funded by the Australian Learning and Teaching Council which is designed to establish excellence in science learning and teaching in Australian universities. Six universities across the country were chosen for the initial implementation of the project. According to the article, during the duration of the project, leaders will undergo leadership training to equip them with skills necessary to foster change in classroom practices.