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The pivot to online teaching caused by the COVID-19 pandemic enabled science and engineering librarians at Vanderbilt University to expand their teaching roles within graduate-level courses in biomedical engineering, chemistry, and physics. In addition to addressing traditional information literacy skills related to information retrieval and resource evaluation, these new lessons addressed important science process skills such as academic reading, responsible conduct of research, and research data management. A facility with cloud-based teaching tools such as Zoom breakout rooms and Excel for Microsoft 365 allowed for engaging instructional experiences, even within synchronous online instructional environments. By integrating these topics into the graduate curricula, these guest lectures supported the professional development of early career graduate students and deepened relationships with the course instructors of record.

The Zr6 nodes of the metal-organic frameworks (MOFs) UiO-66 and UiO-67 are metal oxide clusters of atomic precision and can be used as catalyst supports. The bonding sites on these nodes - that is, hydrogen-bonded H2O/OH groups on UiO-67 and non-hydrogen-bonded terminal OH groups on UiO-66 - were regulated by modulation of the MOF syntheses. Ir(C2H4)2(C5H7O2) complexes reacted with these sites to give site-isolated Ir(C2H4)2 complexes, each anchored to the node by two Ir-Onode bonds. The supported iridium complexes on these sites have been characterized by infrared (IR) and extended X-ray absorption fine structure (EXAFS) spectroscopies and density functional theory calculations. The ethylene ligands on iridium are readily replaced by CO, and the νCO frequencies of the resultant complexes and those of comparable complexes reported elsewhere show that the support electron-donor tendencies increase in the order HY zeolite 蠐 UiO-66 < UiO-67 (= NU-1000) < ZrO2 < MgO. The sharpness of the IR νCO bands shows that the degree of uniformity of the support bonding sites decreases in the order ZrO2 ≈ UiO-67 ≈ NU-1000 < MgO < UiO-66 蠐 HY zeolite. The reactivity of supported Ir(CO)2 complexes with C2H4 to form Ir(C2H4)(CO) and Ir(C2H4)2(CO) is influenced by the support electron-donor properties, with the reactivity increasing in the order MgO = ZrO2 = NU-1000 (not reactive) < UiO-66 < UiO-67 蠐 HY zeolite. Density functional theory calculations characterizing the complexes supported on NU-1000, UiO-66/67, and HY zeolite concur with the use of the calculated νCO bands as indicators of electron-donor properties of the supported metal catalysts. Our calculations also show that the reactivity of the supported Ir(CO)2 complexes with C2H4 is correlated with the electron-donor properties of the iridium center. The supported Ir(C2H4)2 samples are precatalysts for ethylene hydrogenation and ethylene dimerization, with the activity for each reaction increasing with increasing electron-withdrawing strength of the support.

The catalytic properties of the metal-organic framework Fe2(dobdc), containing open Fe(II) sites, include hydroxylation of phenol by pure Fe2(dobdc) and hydroxylation of ethane by its magnesium-diluted analogue, Fe0.1Mg1.9(dobdc). In earlier work, the latter reaction was proposed to occur through a redox mechanism involving the generation of an iron(IV)-oxo species, which is an intermediate that is also observed or postulated (depending on the case) in some heme and nonheme enzymes and their model complexes. In the present work, we present a detailed mechanism by which the catalytic material, Fe0.1Mg1.9(dobdc), activates the strong C-H bonds of ethane. Kohn-Sham density functional and multireference wave function calculations have been performed to characterize the electronic structure of key species. We show that the catalytic nonheme-Fe hydroxylation of the strong C-H bond of ethane proceeds by a quintet single-state σ-attack pathway after the formation of highly reactive iron-oxo intermediate. The mechanistic pathway involves three key transition states, with the highest activation barrier for the transfer of oxygen from N2O to the Fe(II) center. The uncatalyzed reaction, where nitrous oxide directly oxidizes ethane to ethanol is found to have an activation barrier of 280 kJ/mol, in contrast to 82 kJ/mol for the slowest step in the iron(IV)-oxo catalytic mechanism. The energetics of the C-H bond activation steps of ethane and methane are also compared. Dehydrogenation and dissociation pathways that can compete with the formation of ethanol were shown to involve higher barriers than the hydroxylation pathway.