Multicomponent reactions enable the synthesis of large molecular libraries from relatively few inputs. This scalability has led to the broad adoption of these reactions by the pharmaceutical industry. Here, we employ the four-component Ugi reaction to demonstrate that multicomponent reactions can provide a basis for large-scale molecular data storage. Using this combinatorial chemistry we encode more than 1.8 million bits of art historical images, including a Cubist drawing by Picasso. Digital data is written using robotically synthesized libraries of Ugi products, and the files are read back using mass spectrometry. We combine sparse mixture mapping with supervised learning to achieve bit error rates as low as 0.11% for single reads, without library purification. In addition to improved scaling of non-biological molecular data storage, these demonstrations offer an information-centric perspective on the high-throughput synthesis and screening of small-molecule libraries.

Introducing chemical equilibrium concepts in undergraduate general chemistry promotes improved understanding of chemical reactions. We have developed an engaging laboratory experiment exploring the equilibrium of cobalt complexation in alcohols using UV−vis spectroscopy and successfully implemented in a large general chemistry class of 378 students at Brown University. The octahedral to tetrahedral (pink to blue) cobalt complex transition generates vivid visualizations, increasing students' interest in learning. The equilibrium constants can be measured using UV−vis absorption spectroscopy and the Beer−Lambert law. Vast differences in molar absorptivity coefficients between octahedral and tetrahedral geometries of cobalt complexes prompt discussions on absorptivity, orbital splitting, and color change under the purview of learning Le Chatelier's principle. Additionally, the experimental results regarding the equilibrium constant allowed students to examine possible mechanistic pathways. Student responses to conducting the experiment were positive, most notably because this experiment encouraged them to analyze their experimental results critically and propose possible reaction mechanisms and equilibrium expressions while appreciating the sharp color transition that the complexation equilibrium undergoes.

A majority of the electricity currently generated is regrettably lost as heat. Engineering high-efficiency thermoelectric materials which can convert waste heat back into electricity is therefore vital for reducing our energy fingerprint. ZT, a dimensionless figure of merit, acts as a beacon of promising thermoelectric materials. However, engineering materials with large ZT values is practically challenging, since maximizing ZT requires optimizing many interdependent material properties. Motivated by recent studies on bulk indium selenide that suggest it may have favorable thermoelectric properties, here we present the thermoelectric properties of monolayer indium selenide in the presence of uniaxial strain using first-principles calculations conjoined with semiclassical Boltzmann transport theory. Our calculations indicate that conduction band convergence occurs at a compressive strain of −6% along the zigzag direction and results in an enhancement of ZT for p-type indium selenide at room temperature. Further enhancements occur at −7% as the valence bands similarly converge, reaching a maximum ZT value of 0.46, which is one of the largest monolayer InSe figures of merit recorded to date at room temperature. The importance of strain is directly reflected by the enhanced transport coefficients observed at strains nearing those which give rise to the band degeneracies we observe. Our studies demonstrate that strain-induced transitions can play a key role in the engineering of promising thermoelectric materials.