A widely used principle is that shifts in the wavenumber of carboxylate stretching modes upon bonding with a metal center can be used to infer if the geometry of the bonding is monodentate or bidentate. We have tested this principle with ab initio modeling for aqueous metal carboxylate complexes and have shown that it does indeed hold. Modeling of the bonding of acetate and formate in aqueous solution to a range of cations was used to predict the infrared spectra of the metal-carboxylate complexes, and the wavenumbers of the symmetric and antisymmetric vibrational modes are reported. Furthermore, we have shown that these shifts in wavenumber occur primarily due to how bonding with the metal changes the carboxylate C-O bond lengths and O-C-O angle.

Aqueous pK(a) values are calculated from first principles for a set of carboxylic acids using the SMD solvation model with various model chemistries, thermodynamic cycles, and treatments of explicit solvation. In all, 108 unique theoretical protocols are examined. The direct (D) and water proton exchange (PX) cycles are trialled along with a new approach, termed the semidirect (SD) cycle. The SD thermodynamic cycle offers some improvements over the D and PX schemes, as it bypasses the gas-phase heterolytic bond dissociation calculation required in the conventional D approach while also avoiding an aqueous OH(-) calculation required by the PX method when using water as the reference acid. With all three cycles, the recommended model chemistry employs M05-2X/cc-pVTZ Gibbs energies of solvation with a single discrete water molecule and a high-level composite method for the gas-phase reaction energies. With the SD cycle, these calculations result in a mean unsigned error of less than 1 pK(a) units, with respective mean signed error and maximum unsigned error of less than 0.5 and 2 pK(a) units. Similar results are obtained with the D and PX cycles, and further improvement is required in both the gas and aqueous phase ab initio energy calculations before we can truly discriminate between the thermodynamic cycles investigated here.

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To gain insight into how citrate bonds to ZnO, we have studied how aqueous citrate bonds to zinc cations (Zn2+) as well as zinc oxide nanoclusters [(ZnO)n, n=8 to 12] through density functional theory modelling. The infrared (IR) spectra of each complex in water has been calculated at the M05‐2X/cc‐pVTZ level of theory with the SMD solvent model and is presented over the region of 1700 cm−1 to 1250 cm−1; this region corresponds to the stretching modes of the carboxylate group, which change when bonding occurs. Citrate forms bidentate chelating and monodentate bonds with Zn2+; bidentate bonds result in antisymmetric stretching modes of lower wavenumber, while monodentate bonds result in higher wavenumber modes. The most stable structures involve bonds between multiple carboxylate groups and the Zn2+ and sometimes involve the hydroxyl group. Carboxylate groups not involved in bonding generally do not exhibit shifts in their infrared spectra. Similar trends are also observed in complexes of (Zn)2‐citrate, (Zn)3‐citrate and (Zn)‐citrate2. Citrate bonds weakly with the nanoclusters, forming one or two monodentate bonds to different zinc atoms; the IR spectra are not as strongly affected as when bonding occurs with Zn2+.

The ongoing coronavirus pandemic required us to quickly adapt and familiarise ourselves with new skills and technologies in the shift to online teaching. Irregular communication due to extended lockdowns has meant that while knowledge on effective online teaching has been developed, this knowledge has not been properly disseminated to our junior teaching staff. As they operate predominantly in student-facing positions, it is essential that our junior staff be equipped with information on best practice in online teaching as well as with an awareness of the resources available to support them. PURPOSE OR GOALTo address the gap outlined above, we developed a new professional development program for our junior teaching staff, focusing mainly on online teaching. The goal was to share our collective knowledge on best practice in online teaching, and to demonstrate how various technologies could aid in promoting active learning in an online setting. The program also aimed to initiate a community of practice around teaching and the online teaching space. APPROACH OR METHODOLOGY/METHODSIn designing our program, we considered student feedback from previous semesters, and more recent feedback on the online teaching experience from 2020. The final program covered the following topics: general advice, navigating Zoom and physical setup for online teaching, online tools for active learning, engagement within teaching teams, online feedback, and blended synchronous learning. Tools and technologies showcased in the program were embedded in the delivery to allow first-hand experience. ACTUAL OR ANTICIPATED OUTCOMESAn exit survey indicated that in general, participants found the program useful, with an average rating of 8.27 (out of 10). The top areas that participants indicated that they would like more assistance were quizzes and tools for active learning (31%), providing feedback to students (22%), and blended synchronous learning (20%). Zoom (12%) and the physical setup for online teaching (15%) did not rank highly, in line with our observation that a large percentage of participants had some prior experience with online teaching in 2020. CONCLUSIONS/RECOMMENDATIONS/SUMMARYIn summary, we piloted a professional development focused mainly on online-teaching for junior staff. The program was well-received, and the collected feedback will used for implementation and improvement of future run.