The ability to communicate scientific concepts to expert and nonexpert audiences is an essential skill for chemistry and STEM students. Current chemistry curricula mainly focus on developing skills to communicate technical information to expert audiences, while relaying the same information to general audiences receives much less attention. Although numerous initiatives work to close this gap, many have logistical or financial barriers that make them difficult to integrate in a large classroom setting. Herein, we present an assignment focused on improving advanced students' (i.e., graduate and advanced undergraduate students) ability to communicate current organometallic chemistry research (i.e., technical information) to a general audience using infographics. Our assignment features a unique, iterative feedback model incorporating instructor, peer, and near-peer (general audience) groups to provide students with multiple opportunities to refine their communication skills. Anonymous student self-assessments of advanced undergraduate/ graduate students (infographic creators and peer reviewers) and first year, non-major undergraduate students (near-peer reviewers and general audience) indicate that the assignment led to (i) increased confidence in communication skills (advanced undergraduate/graduate students), (ii) a broadened understanding of advanced chemistry in everyday life (both), and (iii) increased recognition for the importance of scientific communication to different audiences (both). Reflections on student outcomes as well as recommendations and considerations for instructors are discussed.

The structures of three racemic (tetrahydro-[1,3]dioxino[5,4-d][1,3]dioxin-4-yl)methanol derivatives are reported, namely, 4-[(methylsulfonyloxy)methyl]-2,4,4a,6,8,8a-hexahydro-[1,3]dioxino[5,4-d][1,3]dioxine, C8H14O7S, 1, 4-[(benzyloxy)methyl]-2,4,4a,6,8,8a-hexahydro-[1,3]dioxino[5,4-d][1,3]dioxine, C14H18O5, 2, and 4-[(anilinocarbonyl)methyl]-2,4,4a,6,8,8a-hexahydro-[1,3]dioxino[5,4-d][1,3]dioxine, C14H17NO6, 3. Mesylate ester 1 at 173 K has triclinic P\overline{1} symmetry and both benzyl ether 2 at 173 K and phenyl urethane 3 have monoclinic P21/c symmetry. These structures are of interest because of the conformation of the cis-fused tetraoxadecalin ring system. This cis-bicyclo[4.4.0]decane ring system, i.e. cis-decalin, can undergo conformational equilibration. In the two most stable conformers, both six-membered rings adopt a chair conformation. However, there are significant consequences in these two stable conformers, with heteroatom substitution at the 1,3,5,7-ring positions as described. Only one conformation, denoted as `concave' or `inside', is found in these crystal structures. This is consistent with previously reported structures of the 1,1-geminal dihydroxy aldehyde and tosylate analogs.

AbstractAn efficient CuPd nanoparticle (NP) catalyst (3 nm CuPd NPs deposited on carbon support) is designed for catalyzing electrochemical allylic alkylation in water/isopropanol (1:1 v/v) and 0.2 m KHCO3 solution at room temperature. The Pd catalysis was Pd/Cu composition‐dependent, and CuPd NPs with a Pd/Cu ratio close to one are the most efficient catalyst for the selective cross‐coupling of alkyl halides and allylic halides to form C−C hydrocarbons with product yields reaching up to 99 %. This NP‐catalyzed electrochemical allylic alkylation expands the synthetic scope of cross‐coupling reactions and can be further extended to other organic reaction systems for developing green chemistry electrosynthesis methods.

The surfaces of icy moons are covered by fractures, other tectonic features, and active or ancient remains of cryovolcanism. These observations suggest active or recent tectonics, but there is still much unknown about the specific conditions surrounding the formation of these features. One important process leading to the fracture of the ice shell is the freezing and consequent pressurization of its ocean, because water expands upon freezing. However, the influence of dissolved non‐condensable gases (herein referred to as volatiles) on the aforementioned dynamics remains poorly constrained. In this study, we present a new experimental investigation to explore the effect of dissolved volatiles in the internal pressure evolution of 10 cm diameter water spheres subjected to freezing temperatures between ~−60°C and ~−20°C. Our experiments reveal that spheres with a reduced initial amount of volatiles dissolved undergo an abrupt transition with dramatic increase of (a) the time between consecutive ice shell fractures and (b) the pressure required to break the shell. We show from a simple numerical model that this transition occurs when exsolution (i.e., nucleation and growth of bubbles) occurs and the fluid inside the shell becomes significantly more compressible. Exsolution is, in turn, triggered by the gradual thickening of the ice shell, which increases the concentration of dissolved volatiles and eventually leads to saturation. These results suggest that the content of volatiles of icy satellites plays a significant role in their geologic history and potential for habitability.

We reported the first systematic study of the solid-state aldol reactions of solvated and unsolvated lithium pinacolone enolate with a variety of solid aromatic aldehydes utilizing a mortar and pestle condition in comparison with the simple ball milling condition or tetrahydrofuran (THF) solution condition. In solution, the reactions are highly-selective with the aldol condensation product at room temperature. Under the condition of mortar and pestle, the reactions with unsolvated lithium pinacolone enolate showed the mixture of aldol condensation product and aldol addition product at room temperature. With the usage of solvated lithium pinacolone enolate, higher yields for most substrates were obtained. Furthermore, repeating the reactions under a simple ball billing condition with no other precautions at room temperature, we achieved high selectivity and yield of products for all substrates, indicating the powerful ability and the utility of solid-state, mechanochemical aldol reaction conditions.

A mononuclear W(iv) bis-dithiolene complex stabilized by an oxo ligand shows a reductive reactivity toward CO2, from which formate and a dinuclear W(v) complex are generated. An unusual structural rearrangement was observed during the reaction. Structural and spectroscopic characterization for a novel triply bridged dinuclear W(v) complex is reported.

OF CURVATURE AND DISSOLVED GAS ON SURFACE FEATURES​. E. Nathan​1​, M. Berton​2​, T. Girona​3​, H. Karani​4​, C. Huber​1​, J. Head​1​, and P. Williard​ 5​, ​1​Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, RI 02912, USA, (erica_nathan@brown.edu), ​2​College of Engineering, Virginia Commonwealth University, ​3​Jet Propulsion Laboratory, California Institute of Technology, ​4​Department of Engineering Sciences and Applied Mathematics, Northwestern University, ​5​Department of Chemistry, Brown University.

THE DYNAMICS OF SUBSURFACE GLOBAL OCEANS. T. Girona1, M. Berton2, H. Karani3,4, C. Huber3, J. Head3, P.G. Williard2, and A. Denton3. 1Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA. 2Department of Chemistry, Brown University, Providence, RI 02912, USA. 3Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, RI 02912, USA. 4Department of Engineering Sciences & Applied Mathematics, Northwestern University, Evanston, IL 60208, USA.

Solution characterizations and ligand binding constants were determined for n-butyllithium in hydrocarbon and ethereal solvents using diffusion-ordered NMR. In hydrocarbon solvents, n-butyllithium exists primarily as an octamer at -40 °C and deaggregates to a hexamer when the temperature is increased. In the presence of THF or diethyl ether, n-butyllithium exists predominantly as a tetra-solvated tetramer and deaggregates to a tetra-solvated dimer in the presence of a large excess or neat THF. The ligand binding constants for the tetra-solvated tetramers were measured using 1H NMR/DOSY titration.

N-Acetylglucosaminidases (GlcNAcases) play an important role in the remodeling and recycling of bacterial peptidoglycan by degrading the polysaccharide backbone. Genetic deletions of autolysins can impair cell division and growth, suggesting an opportunity for using small molecule autolysin inhibitors both as tools for studying the chemical biology of autolysins and also as antibacterial agents. We report here the synthesis and evaluation of a panel of diamides that inhibit the growth of Bacillus subtilis. Two compounds, fgkc (21) and fgka (5), were found to be potent inhibitors (MIC 3.8 ± 1.0 and 21.3 ± 0.1 μM, respectively). These compounds inhibit the B. subtilis family 73 glycosyl hydrolase LytG, an exo GlcNAcase. Phenotypic analysis of fgkc (21)-treated cells demonstrates a propensity for cells to form linked chains, suggesting impaired cell growth and division.

We report the direct measurement of ligand-binding constants of organolithium complexes using a 1H NMR/diffusion-ordered NMR spectroscopy (DOSY) titration technique. Lithium hexamethyldisilazide complexes with ethereal and ester donor ligands (THF, diethyl ether, MTBE, THP, tert-butyl acetate) are characterized using 1H NMR and X-ray crystallography. Their aggregation and solvation states are confirmed using diffusion coefficient-formula weight correlation analysis, and the 1H NMR/DOSY titration technique is applied to obtain their binding constants. Our work suggests that steric hindrance of ethereal ligands plays an important role in the aggregation, solvation, and reactivity of these complexes. It is noteworthy that diffusion methodology is utilized to obtain binding constants.

Lithium β-ketocarboxylates 1(COOLi), prepared by the reaction of lithium enolates 2(Li+) with carbon dioxide, readily undergo decarboxylative disproportionation in THF solution unless in the presence of lithium salts, in which case they are indefinitely stable at room temperature in inert atmosphere. The availability of stable THF solutions of lithium β-ketocarboxylates 1(COOLi) in the absence of carbon dioxide allowed reactions to take place with nitrogen bases and alkyl halides 3 to give α-alkyl ketones 1(R) after acidic hydrolysis. The sequence thus represents the use of carbon dioxide as a removable directing group for the selective monoalkylation of lithium enolates 2(Li+). The roles of lithium salts in preventing the disproportionation of lithium β-ketocarboxylates 1(COOLi) and in determining the course of the reaction with bases and alkyl halides 3 are discussed.

We report on the generation of a perfluoroalkyl Grignard reagent ((F)RMgX) by exchange reaction between a perfluoroalkyl iodide ((F)R-I) and a Grignard reagent (RMgX). (19)F NMR was applied to monitor the generation of n-C3F7MgCl. Additional NMR techniques, including (19)F COSY, NOESY, and pulsed gradient spin-echo (PGSE) diffusion NMR, were invoked to assign peaks observed in (19)F spectrum. Schlenk equilibrium was observed and was significantly influenced by solvent, diethyl ether, or THF.

A new Au22 nanocluster, protected by bis(2-diphenyl-phosphino)ethyl ether (dppee or C28 H28 OP2 ) ligand, has been synthsized and purified with high yield. Electrospray mass spectrometry shows that the new cluster has a formula of Au22 (dppee)7 , containing 22 gold atoms and seven dppee ligands. The cluster is found to be stable as a solid, but metastable in solution. The new cluster has been characterized by UV-Vis-NIR absorption spectroscopy, collision-induced dissociation, and (31) P-NMR. The properties of the new cluster have been compared with the previous Au22 (dppo)6 nanocluster (dppo = 1,8-bis(diphenyl-phosphino)octane or C32 H36 P2 ), which contains two fused Au11 units. All the experimental data indicate that the new Au22 (dppee)7 cluster is different from the previously known Au22 (dppo)6 cluster and represents a new Au22 core, which contains most likely one Au11 motif with several Au2 (dppee) or Au(dppee) units. The Au22 (dppee)7 cluster provides a new example of the ligand effects on the nuclearity and structural polymorphism of phosphine-protected atom-precise gold nanoclusters.