Achieving Balanced Energetics through Cocrystallization

Achieving energetic materials with a balanced ratio of oxidant to fuel is a challenge that has been difficult to meet through molecular synthesis. The alternative approach, composite formulation, fails to achieve intimate association of the components to the detriment of performance. Herein, the energetic oxidizer ammonium dinitramide (ADN) is combined with fuel‐rich pyrazine‐1,4‐dioxide via cocrystallization. The result is a material with a balanced oxidant/fuel ratio in which the components maintain intimate association. The material exhibits desirable physical and energetic properties which are much improved over ADN and comparable to contemporary energetics.Balanceakt: Eine neu entwickelte Methode ermöglicht die Herstellung von sauerstoffbalancierten energetischen Materialien durch Kokristallisation. Sie vermeidet die Risiken der molekularen Synthese und erreicht eine innige Verbindung von oxidierenden und Brennstoffgruppen. Angewendet auf Ammoniumdinitramid macht die Methode ein energetisches Material mit verbesserten physikalischen und energetischen Eigenschaften zugänglich.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152711/1/ange201908709-sup-0001-misc_information.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/152711/2/ange201908709.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/152711/3/ange201908709_am.pd

Anion–Cation Mediated Structural Rearrangement of an In-derived Three-Dimensional Interpenetrated Metal–Organic Framework

Postsynthetic modification of metal–organic frameworks (MOFs) has proven an effective method of synthesizing architectures that have proven challenging to produce via classic solvothermal means. Herein we report the anion–cation assisted solid-state transformation of a three-dimensional MOF (ATF-1) to a series of two-dimensional structures (YCM-21-Z) via treatment with quaternary ammonium halides. It is important to note that this reaction requires no exogoneous building blocks (inorganic cation and/or organic linker) for conversion to occur. This reaction led to the synthesis of a chemically unique framework YCM-21-Bnpy in which phase-pure synthesis cannot be achieved by solvothermal means. The mechanism of transformation was studied with data supporting a nucleophilic halide (Br, Cl, or F) mediated de-intercalation and cation-assisted flattening of the In secondary building unit as the key mechanistic steps

Role of Elevated S-adenosylhomocysteine in Rat Hepatocyte Apoptosis: Protection by Betaine

Previous studies from our laboratory have shown that ethanol consumption results in an increase in hepatocellular S-adenosylhomocysteine levels. Because S-adenosylhomocysteine is a potent inhibitor of methylation reactions, we propose that increased intracellular S-adenosylhomocysteine levels could be a major contributor to ethanol-induced pathologies. To test this hypothesis, hepatocytes isolated from rat livers were grown on collagen-coated plates in Williams’ medium E containing 5% FCS and exposed to varying concentrations of adenosine in order to increase intracellular S-adenosylhomocysteine levels. We observed increases in caspase-3 activity following exposure to adenosine. This increase in caspase activity correlated with increases in intracellular S-adenosylhomocysteine levels and DNA hypoploidy. The adenosine-induced changes could be significantly attenuated by betaine administration. The mechanism of betaine action appeared to be via the methylation reaction catalyzed by betaine-homocysteine-methyltransferase. To conclude, our results indicate that the elevation of S-adenosylhomocysteine levels in the liver by ethanol is a major factor in altering methylation reactions and in increasing apoptosis in the liver. We conclude that ethanol-induced alteration in methionine metabolic pathways may play a crucial role in the pathologies associated with alcoholic liver injury and that betaine administration may have beneficial therapeutic effects