Unprecedented Packing Polymorphism of Oxindole: An Exploration Inspired by Crystal Structure Prediction.

Crystal polymorphism, characterized by different packing arrangements of the same compound, strongly ties to the physical properties of a molecule. Determining the polymorphic landscape is complex and time-consuming, with the number of experimentally observed polymorphs varying widely from molecule to molecule. Furthermore, disappearing polymorphs, the phenomenon whereby experimentally observed forms cannot be reproduced, pose a significant challenge for the pharmaceutical industry.

"Click"-Like η -Metalation/Demetalation of Aryl Iodides as a Means of Turning "ON/OFF" Halogen Bond Donor Functionality.

η -Metalated aryl halides are recognized as a class of halogen bond (XB) donors. Click-like η -metalation/demetalation of aryl iodides by cyclopentadienylruthenium(II) ([CpRu ] ) is shown to turn ON/OFF (amplify/suppress) XB donor functionality. [CpRu(MeCN) ][PF ] is shown to react quantitatively with iodobenzenes (ArI , n=1,2) to yield [CpRu(η -ArI )][PF ] compounds.