During the COVID-19 pandemic, an at-home laboratory program was created and implemented for a section of the general chemistry course at the University of Southern California. The experiments were designed to only utilize safe household items and no special equipment. These laboratory activities, spanning over 4 weeks, focused on concepts usually covered in the final one-third of our second-semester chemistry laboratory, including pH, acid−base titrations, buffers, solubility, phase equilibria, and thermodynamics. In this article, we describe the design of the laboratories and our experience with this experiment, while also providing an assessment on how similar activities could be integrated profitably into a regular general chemistry course.

We describe the solid-state structural evolution in four hybrid hexaiodoplatinate(IV) compounds, demonstrating the increasingly important role that extended hydrogen bonding plays in directing the structure across the series. The compounds are APtI, where A is one of the following amines: ammonium, NH; methylammonium, CHNH; formamidinium, CH(NH); guanidinium, C(NH). These are closely related in structure and properties to the hybrid halide perovskites of lead(II) that have recently established their prowess in optoelectronics. The first three of these compounds crystallize in the vacancy-ordered double perovskite APt□I (□ indicates a vacant site) structure in the KPtCl archetype, despite the relatively large perovskite tolerance factors involved. The last compound, (GUA)PtI, crystallizes in a vacancy-ordered variant of the hexagonal CsNiCl structure: the KMnF structure. A combination of solid-state Pt andH NMR spectroscopy and detailed density functional theory calculations helps to reveal structural trends and establish the hydrogen-bonding tendencies. The calculations and measured optical properties support the surprising observation in these iodosalt compounds that, for smaller A cations, the conduction bands are considerably disperse, despite lacking extended I-Pt-I connectivity.

Perovskite-derived hybrid platinum iodides with the general formula A2PtIVI6 (A = formamidinium FA and guanidinium GUA) accommodate excess I2 to yield hydrogen-bond-stabilized compounds where the I2 forms catenates with I− anions on the PtI6 octahedra.

Shear-phase early transition metal oxides, mostly of Nb, and comprising edge-and corner-shared metal−oxygen octahedra have seen a resurgence in recent years as fast-charging, low-voltage electrodes for Li + -ion batteries. Mo oxides, broadly, have been less well studied as fast-charging electrodes.Here we examine a reduced Mo oxide, Mo 4 O 11 , that has a structure comprising only corner-connected MoO 4 tetrahedra and MoO 6 octahedra. We show that an electrode formed using micrometer-sized particles of Mo 4 O 11 as the active material can function as a high-rate Li + -ion electrode against Li metal, with a stable capacity of over 200 mAh g −1 at the high rate of 5C. Operando X-ray diffraction (XRD), entropic potential measurements, and ex situ Raman spectroscopy are employed to understand the nature of the charge storage. The crystal structure dramatically changes upon the first lithiation, and subsequent cycling is completely reversible with low capacity fade. It is the newly formed and potentially more layered structure that demonstrates high-rate cycling and small voltage polarization. A space group and unit cell for the new structure is proposed. This finding expands the scope of candidate highrate electrode materials to those beyond the expected Nb-containing shear-phase oxide materials.