Three intrinsic properties of solvent were used to evaluate the effects of solvent on polymorph formation of prasugrel hydrochloride. In situ Raman spectroscopy, FTIR, and powder X-ray diffraction were used to characterize two solvent-free polymorphs and five solvates of prasugrel hydrochloride, the two of which were reported for the first time. Reactive crystallization in 24 different pure solvents was studied at 313.15 K. It was found that polymorph formation of prasugrel hydrochloride directly depends on the solvents used in the experiments. Form I was obtained in solvents with low values of hydrogen bond donor ability (HBD), while form II was obtained in solvents with high values of HBD. The thermodynamic and kinetic reasons for the solvent effects were explained by using the solubility data and the nucleation experiments. The solubilities of forms I and II were experimentally determined by a gravimetric method, and an equation based on the linear free energy approach for predicting solubility was applied to correlate the solubility of form II. It was found that the values of HBD of the solvents also affect the solubility of prasugrel hydrochloride. From desolvation experiments of the five solvates in seven pure solvents at 293.15 and 313.15 K, it was found that the polymorphs of prasugrel hydrochloride obtained after desolvation are closely related to the solvents. The heterogeneous nucleation of form I during the solvent-mediated polymorphic transformation was also studied at 313.15 K, and it was found that the solute–solvent interactions will also affect the nucleation rate of form I. A hypothesis was then proposed that prasugrel hydrochloride form I is prone to crystallize when van der Waals force dominates the interaction between the solute and the solvent molecules, while prasugrel hydrochloride form II is prone to nucleate and grow when hydrogen bonding dominates the interaction between the solute and the solvent molecules.

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Nonmonotonic composition dependence is often observed for numerous properties in the aqueous mixtures of small amphiphilic molecules. The molecular picture underlying this structure–activity relationship, however, remains largely elusive. We herein studied water reorientation dynamics in the aqueous mixture of dimethyl sulfoxide (DMSO), which has a significant nonmonotonic composition dependence, using molecular dynamic simulation and an extended molecular jump model. The analysis indicates that this nonideal behavior is driven by the collective frame diffusion component of water reorientation, which decelerates in the water-rich regime because of the strengthened hydrogen bonds and accelerates in the water-poor regime as the hydrogen bonding network is broken into smaller aggregates. The current work therefore connects the microheterogeneity in the solvation structure of DMSO–water with its nonmonotonic hydration dynamics and sheds new light on how microsegregation leads to the multiscale hydration nonideality in general.

A solid zirconiumdodecatungstophosphate Zr 0.7 H 0.2 PW 12 O 40 (abbreviated as ZrHPW) with nanotube structure has been synthesized using natural cellulose fiber as a template. The structure and morphology were characterized to show that the primary Keggin structure remained intact in a nanotube with large surface area (256 m 2 /g). On the basis of the research of acidity, ZrHPW exhibited higher acid strength, both Brønsted acidity and Lewis acidity in one to show higher efficiency, and reusable catalytic activity in biodiesel production from low-quality feedstocks. A synergistic effect results from the channels in the nanotube and doubly catalytic sites to provide an efficient approach to acidic sites for reactants, as well as enough space for subsequent recycling.