Crystallographic investigation into the self-assembly, guest binding, and flexibility of urea functionalised metal-organic frameworks

Introduction of hydrogen bond functionality into metal-organic frameworks can enhance guest binding and activation, but a combination of linker flexibility and interligand hydrogen bonding often results in the generation of unwanted structures where the functionality is masked. Herein, we describe the self-assembly of three materials, where Cd2+, Ca2+, and Zn2+ are linked by N,Nʹ-bis(4-carboxyphenyl)urea, and examine the effect of the urea units on structure formation, the generation of unusual secondary building units, structural flexibility, and guest binding. The flexibility of the Zn MOF is probed through single-crystal to single-crystal transformations upon exchange of DMF guests for CS2, showing that the lability of the [Zn4O(RCO2)6] cluster towards solvation enables the urea linkers to adopt distorted conformations as the MOF breathes, even facilitating rotation from the trans/trans to the trans/cis conformation without compromising the overall topology. The results have significant implications in the mechanistic understanding of the hydrolytic stability of MOFs, and in preparing heterogeneous organocatalysts

Experiential Learning is the Key to Enriching Student Success and Advancing Cancer Research Education

Cancer is the leading cause of death in Canada, transcending all ages, genders, ethnicities, and socioeconomic status. However, many Canadians are unaware that cancer is a diverse set of diseases that require different diagnostic tools and treatment strategies. Thus, public education focusing on cancer research is critical to change the current conversation around the disease. The development of educational tools that engage and clearly illustrate the mechanisms of cancer research is a justified social need that requires proper training. It is hypothesized that university students immersed in cancer research and education through experiential learning become effective community educators. The Windsor Cancer Research Group (WCRG) offers many experiential learning opportunities for undergraduate and graduate students by connecting them to local researchers, health care professionals, patients and caretakers. To obtain an empirical measure of the program’s success and needs for improvement, a survey was developed that investigates how these opportunities enrich technical and transferable skills, reinforce interest in biomedical careers, encourage students to be community educators and build self-efficacy. The survey has been distributed to current and past student participants of WCRG’s experiential learning opportunities. After two weeks, results will be collected and assessed to obtain a better understanding of the effects of experiential learning while also demonstrating the impact of enhancing academic programs through experiential learning. Creating an accessible platform for the public to learn more about cancer research, and its impact on patient care also addresses a clear social need that promotes healthy and safe communities within Windsor-Essex

The semiquinone radical anion of 1,10-phenanthroline-5,6-dione: synthesis and rare earth coordination chemistry

Reduction of 1,10-phenanthroline-5,6-dione (pd) with CoCpR2 resulted in the first molecular compounds of the pd˙− semi-quinone radical anion, [CoCpR2]+[pd]˙− (R = H, (1); R = Me4, (2)). Furthermore compounds 1 and 2 were reacted with [Y(hfac)3(thf)2] (hfac = 1,1,1-5,5,5-hexafluoroacetylacetonate) to synthesise the rare earth-transition metal heterometallic compounds, [CoCpR2]+[Y(hfac)3(N,N′-pd)]˙− (R = H, (3); R = Me4, (4))

The modular synthesis of rare earth-transition metal heterobimetallic complexes utilizing a redox-active ligand

We report a robust and modular synthetic route to heterometallic rare earth-transition metal complexes. We have used the redox-active bridging ligand 1,10-phenathroline-5,6-dione (pd), which has selective N,N′ or O,O′ binding sites as the template for this synthetic route. The coordination complexes [Ln(hfac)3(N,N’-pd)] (Ln = Y [1], Gd [2]; hfac = hexafluoroacetylacetonate) were synthesised in high yield. These complexes have been fully characterised using a range of spectroscopic techniques. Solid state molecular structures of 1 and 2 have been determined by X-ray crystallography and display different pd binding modes in coordinating and non-coordinating solvents. Complexes 1 and 2 are unusually highly coloured in coordinating solvents, for example the vis-NIR spectrum of 1 in acetonitrile displays an electronic transition centred at 587 nm with an extinction coefficient consistent with significant charge transfer. The reaction between 1 and 2 and VCp2 or VCpt2 (Cpt = tetramethylcyclopentadienyl) resulted in the isolation of the heterobimetallic complexes, [Ln(hfac)3(N,N′-O,O′-pd)VCp2] (Ln = Y [3], Gd [4]) or [Ln(hfac)3(N,N′-O,O′-pd)VCpt2] (Ln = Y [5], Gd [6]). The solid state molecular structures of 3, 5 and 6 have been determined by X-ray crystallography. The spectroscopic data on 3–6 are consistent with oxidation of V(II) to V(IV) and reduction of pd to pd2− in the heterobimetallic complexes. The spin-Hamiltonian parameters from low temperature X-band EPR spectroscopy of 3 and 5 describe a 2A1 ground state, with a V(IV) centre. DFT calculations on 3 are in good agreement with experimental data and confirm the SOMO as the dx2−y2 orbital localised on vanadium

Experiential Learning is the Key to Developing Transferable Skills in Cancer Research and Education

Although cancer is the leading cause of death in Canada, many Canadians are unaware that cancer is a diverse set of diseases that require different diagnostic tools and treatment strategies. Thus, education focusing on cancer research is critical to advance current public conversations around the disease. It is hypothesized that university students immersed in cancer research and education through experiential learning become effective community educators. The Windsor Cancer Research Group (WCRG) offers many experiential learning opportunities for undergraduate and graduate students by connecting them to local researchers, health care professionals, patients and caretakers. In order to gain more insight into an empirical measure of the training program’s success and needs for improvement, a survey was developed to assess both the transferable skills acquired by student participants of WCRG’s experiential learning opportunities. The results from this study show that these experiences enrich the training of students, reinforces their interest in biomedical careers, encourages them to be community educators, and builds self-efficacy. Student involvement in creating accessible platforms embedded with educational tools for the public, and its impact on patient care, also addresses a clear social need for proper communication about cancer research and the promotion of healthy and safe communities

A new approach to generating research-quality phenology data: The USA National Phenology Monitoring System

The USA National Phenology Network (www.usanpn.org) has recently initiated a national effort to encourage people at different levels of expertise—from backyard naturalists to professional scientists—to observe phenology and contribute to a national database that will be used to greatly improve our understanding of spatio-temporal variation in phenology and associated phenological responses to climate change. Many phenological observation protocols identify specific single dates at which individual phenological events are observed, but the scientific usefulness of long-term phenological observations can be improved with a more carefully structured protocol. At the USA-NPN we have developed a new approach that directs observers to record each day that they observe an individual plant, and to assess and report the state of specific life stages (or phenophases) as occurring or not occurring on that plant for each observation date. Observations of animal phenophases are similarly recorded, although for a species as a whole rather than for a specific individual. Evaluation is phrased in terms of simple, easy-to-understand, questions (e.g. “Do you see open flowers?”) which makes it appropriate for a broad audience. From this method, a rich dataset of phenological metrics can be extracted, including the duration of a phenophase (e.g. open flowers), the beginning and end points of a phenophase (e.g. traditional phenological events such as first flower and end flowering), multiple distinct occurrences of phenophases within a single growing season (e.g multiple flowering events, common in drought-prone regions), as well as quantification of sampling frequency and observational uncertainties. The system also includes a mechanism for translation of phenophase start and end points into standard traditional phenological events to facilitate comparison of contemporary data collected with this new “phenophase status” monitoring approach to historical datasets collected with the “phenological event” monitoring approach. These features greatly enhance the utility of the resulting data for statistical analyses addressing questions such as how phenological events vary in time and space, and in response to global change

Molecular and electronic structure of the dithiooxalato radical ligand stabilised by rare earth coordination

Heterometallic rare earth transition metal compounds of dithioxalate (dto)2–, [NiII{(dto)LnIIITp2}2] (Ln = Y (1), Gd (2); Tp = hydrotris(pyrazol-1-yl)borate) were synthesised. The Lewis acidic rare earth ions are bound to the dioxolene and chemical reduction of 1 and 2 with cobaltocene yielded [CoCp2]+[NiII{(dto)LnIIITp2}2]˙− Ln = Y (3), Gd (4). The reduction is ligand-based and 3 and 4 are the first examples of both molecular and electronic structural characterisation of the dithiooxalato radical (dto)3˙−

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Illustration of accordion with red, white, and black diamonds in backgroundhttps://scholarsjunction.msstate.edu/cht-sheet-music/7742/thumbnail.jp