ROY confined in hydrogen-bonded frameworks: coercing conformation of a chromophore
Abstract not provided
Tang, Sishuang↗
Engineering topics
Hu, Chunhua T.
Publications and source records attributed to Hu, Chunhua T..
Melt Crystallization for Paracetamol Polymorphism
Trimorphic paracetamol, one of the most commonly used analgesic and antipyretic drugs, has been a model system for studying transformations among phases of molecular crystalline materials. During crystallization from the melt and the glass above 0 °C, three new polymorphs of paracetamol (N-acetyl- para -aminophenol or acetaminophen) were discovered, doubling the number of known ambient forms. The crystal structure of one new form was solved using a combination of powder X-ray diffraction and computational techniques. Growth kinetics became anomalous near the glass transition: as temperature decreased, growth rate increased; this rare and poorly understood phenomenon is commonly identified as the glass-to-crystal (GC) growth mode. In addition, two polymorphs displayed optical evidence of helicoidal morphologies, a characteristic of at least 25% of molecular crystals, that has been resistant to a universal explanation.
36 MATERIALS SCIENCE↗
Guest Exchange through Facilitated Transport in a Seemingly Impenetrable Hydrogen-Bonded Framework
Abstract not provided
Li, Yuantao↗
The Third Ambient Aspirin Polymorph
Polymorphism in aspirin (acetylsalicylic acid), one of the most widely consumed medications, was equivocal until the structure of a second polymorph II, similar in structure to the original form I, was reported in 2005. Here, the third ambient polymorph of aspirin is described. Lastly, it was crystallized from the melt and its structure was determined using a combination of X-ray powder diffraction analysis and crystal structure prediction algorithms.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗