12 research outputs found

    A Bidentate Ligand Featuring Ditopic Lewis Acids in the Second Sphere for Selective Substrate Capture and Activation

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    We present a ligand platform featuring appended ditopic Lewis acids to facilitate capture/activation of diatomic substrates. We show that incorporation of two 9-borabicyclo[3.3.1]nonane (9-BBN) units on a single carbon tethered to a pyridine pyrazole scaffold maintains a set of unquenched nitrogen donors available to coordinate FeII, ZnII, and NiII. Using hydride ion affinity and competition experiments, we establish an additive effect for ditopic secondary sphere boranes, compared to the monotopic analogue. These effects are exploited to achieve high selectivity for binding NO2− in the presence of competitive anions such as F− and NO3−. Finally, we demonstrate hydrazine capture within the second-sphere of metal complexes, followed by unique activation pathways to generate hydrazido and diazene ligands on Zn and Fe, respectively.We report the synthesis of a bidentate ligand featuring secondary sphere ditopic Lewis acids. We verify a Lewis acid additivity effect for the ditopic boranes compared to a monotopic analogue using hydride ion affinity and competition studies. We show chemoselective nitrite capture in the presence of other anions. Pre-organized hydrazine adducts in the second sphere of Zn and Fe are functionalized to hydrazido and diazene ligands, respectively.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/176032/1/ange202218907.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/176032/2/ange202218907_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/176032/3/ange202218907-sup-0001-misc_information.pd

    The UCSC Genome Browser database: 2022 update.

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    The UCSC Genome Browser, https://genome.ucsc.edu, is a graphical viewer for exploring genome annotations. The website provides integrated tools for visualizing, comparing, analyzing, and sharing both publicly available and user-generated genomic datasets. Data highlights this year include a collection of easily accessible public hub assemblies on new organisms, now featuring BLAT alignment and PCR capabilities, and new and updated clinical tracks (gnomAD, DECIPHER, CADD, REVEL). We introduced a new Track Sets feature and enhanced variant displays to aid in the interpretation of clinical data. We also added a tool to rapidly place new SARS-CoV-2 genomes in a global phylogenetic tree enabling researchers to view the context of emerging mutations in our SARS-CoV-2 Genome Browser. Other new software focuses on usability features, including more informative mouseover displays and new fonts
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