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Semiconductor nanocrystals (NCs) offer prospective use as active optical elements in photovoltaics, light-emitting diodes, lasers, and photocatalysts due to their tunable optical absorption and emission properties, high stability, and scalable solution processing, as well as compatibility with additive manufacturing routes. Over the course of experiments, during device fabrication, or while in use commercially, these materials are often subjected to intense or prolonged electronic excitation and high carrier densities. The influence of such conditions on ligand integrity and binding remains underexplored. Here, we expose CdSe NCs to laser excitation and monitor changes in oleate that is covalently attached to the NC surface using nuclear magnetic resonance as a function of time and laser intensity. Higher photon doses cause increased rates of ligand loss from the particles, with upward of 50% total ligand desorption measured for the longest, most intense excitation. Surprisingly, for a range of excitation intensities, fragmentation of the oleate is detected and occurs concomitantly with formation of aldehydes, terminal alkenes, H2, and water. After illumination, NC size, shape, and bandgap remain constant although low-energy absorption features (Urbach tails) develop in some samples, indicating formation of substantial trap states. The observed reaction chemistry, which here occurs with low photon to chemical conversion efficiency, suggests that ligand reactivity may require examination for improved NC dispersion stability but can also be manipulated to yield desired photocatalytically accessed chemical species. 

The structural and electronic adaptability ranges of a [VO(SeO 3 )(HSeO 3 )] framework found in organically templated vanadium selenites were determined using a three step approach, informed by cheminformatics descriptors, involving (i) the extraction of the most important reaction parameters from historical reaction data, (ii) a fractional factorial design on those parameters to better explore chemical space and (iii) decision tree construction on organic molecular properties to determine the factors governing framework formation. This process enabled the elucidation of both the structural and electronic adaptability ranges and provided the context to extract chemical understanding from the structural features that give rise to these respective ranges. This work resulted in the synthesis and structural determination of five new compounds.